Where to find it: Deliver tab > Project Folder Storage > Open Projects…

Prefer a guided walk-through with pictures? See How to: Get started.

Geo-Surface Drain Pro can keep your projects in a folder on your own computer and save your work as you go — the way a desktop program does. You choose the folder once, and from then on every project you create lives inside it.

We suggest making a folder called Geo-Surface Projects somewhere sensible, such as your Documents folder. Inside it, each project gets its own subfolder holding that project's design, elevation data, field boundary and analysis results as ordinary files.

Turning It On

The first time you save a project backup you're offered this with a Store projects in a folder? prompt — after the save, never while you are typing. You can accept it then, or turn it on later from the Project Folder Storage card on the Deliver tab — tick Store projects in a folder on this computer and choose your folder. Once it's on, it stays on.

The first-run prompt offers Choose projects folder… or Not now — and choosing "Not now" costs you nothing. The manual Backup and Restore files described below keep working exactly as before, and you can switch folder storage on whenever you're ready.

Turning it off again later is equally safe: your projects stay on your disk untouched, and the app simply goes back to manual backups until you turn it on again.

It is perfectly normal to open the app, start drawing, pull in LiDAR and drop a reference overlay on the map before you have thought about a name. When you then create a project, everything already on your map becomes part of that project and is written to its folder immediately — nothing is cleared, and nothing is lost. The create form says so, and the confirmation afterwards tells you the work is saved.

If you genuinely want a clean start instead, use Start the new project empty instead beside the Create button. That one clears the map, and it only appears when there is work on the map to clear.

Opening an existing project that happens to be empty is the one case that still clears the map, because that is what opening it means. If the work on screen has never been saved, the app says so in plain words and offers Save it as a new project first, which takes you straight to naming a project for it.

Every so often, when you open the app, your browser may ask you to approve access to your projects folder again. You'll see a Reconnect to projects folder button naming your folder.

This is completely normal and nothing has gone wrong. Browsers deliberately re-check folder permissions from time to time as a safety feature — it stops any website quietly holding on to access to your files forever. As the app puts it: one click and your projects are right where you left them.

If the folder itself has been moved or renamed, the app tells you it can't find it and offers to let you point at it again. Choose the folder in its new location and your projects come straight back.

Because your projects are plain folders on disk, moving your whole working library to another machine is simply a matter of copying the folder.

1. Copy your projects folder — onto a USB drive, an external SSD, or into a cloud-sync folder such as OneDrive, Dropbox or Google Drive
2. On the other computer, open Geo-Surface Pro and choose that folder as your projects folder
3. Every project appears in the list, ready to open

This works because the app finds your projects by looking in the folder — there is no hidden database or index kept somewhere else that has to travel with them. If a project folder is there, it shows up. That also means you can reorganise, copy or archive projects with ordinary file tools and the app will simply reflect what it finds.

Elevation data is the bulky part of a drainage project. A single field carrying high-resolution elevation and a full set of analysis layers is a substantial amount of data, and it adds up quickly once you're managing dozens or hundreds of fields.

If You Manage a Lot of Fields

• Give it a big drive. A serious project library deserves real space. Don't squeeze it onto a nearly-full system drive
• An external SSD is an excellent choice. You can point your projects folder straight at one. It keeps the library off your main drive, and it travels between machines
• Keep an eye on free space. Saving needs somewhere to write, the same as any other program

The single best habit: point one cloud backup at your projects folder and let it run. Everything you do from then on is protected automatically.

While a project is open, your work is saved automatically about every 20 seconds — but only when something has actually changed, so it never writes for the sake of it.

Routine auto-saves happen quietly in the background so you're not interrupted every 20 seconds. After a big step — loading elevation data or a boundary — you'll see a Project saved confirmation.

Checking When It Last Saved

The Project Folder Storage card on the Deliver tab always shows the current state: your project name, when it last saved, and a reminder that auto-save runs about every 20 seconds. The project name also appears beside the app title at the top of the screen — hover it to see the same reassurance.

Saving On Purpose

• Save now — in the Project Folder Storage card on the Deliver tab
• Save & switch project — the circular-arrows button near the right end of the top bar. It saves your work first, then reloads the app and returns you to the project list so you can open something else. If the save can't complete for any reason, the reload is cancelled and you stay exactly where you are — it will never trade your work for a reload. With no project open it asks first (Reload without a project?), because anything unsaved would be lost

Where to find it: Deliver tab > Project Folder Storage > Open Projects… (it also opens by itself when you start the app with folder storage on)

The Projects dialog lists everything in your projects folder. From here you can:

• Open a project — click it in the list
• New project — type a name and click Create (or press Enter). Use something you'll recognise later, such as Smith Farm NW quarter. Whatever is on the map comes with it (see above)
• Restore backup ZIP… — bring a backup file in as a new project in your folder. This is how a design someone emails you joins your working library
• Search — type in Search projects by name... to filter a long list
• See when you last worked on each project — each line shows when it was last opened and saved; the open project is marked OPEN and the others show their region (for example US, CA or UK). The most recently used projects sit at the top
• Delete a project — the trash icon beside it
• Change folder… — point the app at a different projects folder
• Continue without a project — work in a single session without saving to the folder

There are two ways to keep your work, and they're for different jobs. Most people use both.

Your Projects Folder	Backup Files (.zip)
Your day-to-day working library	A single project captured at a moment in time
Saves itself as you work	Created when you click Backup Project
Holds all your projects together	One file, one project
Best for: getting your own work done	Best for: sending a design to someone, or archiving a job

When to Use a Backup File

• Sending a design to a client. They can open it in the free Geo-Surface Viewer to explore the design, the terrain analysis and the 3D view — without needing Geo-Surface Pro and without being able to alter your work
• Sending a project to a colleague or contractor
• Archiving a finished job as a single file you can file away
• Marking a milestone before you try a significantly different design approach

Restoring a Backup While a Project Is Open

A backup never overwrites the project you have open. If you click Restore Project on the Deliver tab while a folder project is open, the app asks first: the open project is saved and closed, stays in your list exactly as it is, and the backup is added as its own new project and opened. Click Save, close and open the backup to go ahead, or Cancel. Restore backup ZIP… in the Projects dialog does the same.

See Project Backup & Restore for everything a backup file contains and exactly how restoring works.

The sidebar on the left holds the three tabs; the map fills the rest, with the drawing tools on its left edge and the map toolbar in its bottom-left corner. The top bar holds the things that apply to the whole app. The profile chart opens along the bottom of the map. See the picture in Welcome.

From left to right:

• Menu button (three lines): hides the sidebar so the map gets the whole width; press it again to bring the sidebar back
• App name and project: the open project's name shows under the app name
• Region button (for example US): the region the app is in; click it to switch region. See Regions
• Workspace: Drainage Design or Landforming (Beta), see Workspaces below
• Find any tool or setting… (Ctrl+K): the tool finder
• Search locations: type a town, road or place to move the map there; it searches the country or region the app is set to
• User manual (book button): opens this manual
• Version (for example v3.3): worth quoting if you contact support
• Units button: each click moves to the next system: in (feet and inches), 0.1 ft (decimal feet) and m (metric). Every panel, map label, profile and report follows. In metric, depths and pipe sizes show in millimetres, areas in hectares and flows in L/s. The units only change how numbers are shown and typed, never the design
• What's New: the release notes; a dot means there is something you have not read
• Help & feedback: the support assistant — see 24/7 Project-Aware AI Support
• Save & switch project (circular arrows): saves the open project and returns to the project list — see Your Projects Folder
• Fullscreen

The three tabs follow the job. The row of buttons under the tabs jumps to the parts of the open tab.

Project — the field

• Define Your Field: Upload field boundary or Draw field boundary; Edit Boundary reshapes it. See Define Project Area
• Get Elevation Data: Download elevation for this field, or Other elevation sources for your own survey, GeoTIFF or an existing design. See Get Elevation Data
• Mark Culverts (optional, Drainage workspace)
• Create Analysis Layers: Create Drainage Layers. See Analysis Layers
• Soil Information for the field
• Project drainage coefficient and Region at the foot of the tab. See Design Parameters

Design — the design itself

In the Drainage workspace the buttons under the tabs are Design, Sizing, Simulation and Surface:

• Design (the Active Design card): pick or find a run, its depths, grades and pipe, and the grade tools Best-Fit, Guided and Freeform. The sliders button beside Active Design opens Drainage settings. See Design Parameters and Grade Analysis & Best Fit
• Sizing (Tile Sizing): Auto Size Mains. See Tile Sizing & Specifications
• Simulation (Drainage simulation, Beta). See Drainage Simulation (Beta)
• Surface (Surface with drains carved in)

The drawing tools are not in the sidebar: they sit on the map (below). In the Landforming workspace the Design tab holds Landforming Design instead — see Landforming.

Deliver — files and backups

One section opens at a time: Send the design to the machine (Beta), Project Backup, Project Folder Storage, Professional Reports, Quick Exports, Overburden guidance, Analysis Data and Raw Data. See Exporting Your Designs and PDF Reports.

Where to find it: Design tab (Drainage workspace) > the rail on the left edge of the map, below the zoom buttons

The tools come in four groups, top to bottom (see Drawing Drain Routes, Laying Out Laterals and Line & Measurement Tools):

• Create: Draw drain, Copy offset, Mirror across the main, Aligned lateral
• Batch: Herringbone laterals, Respace laterals, Update laterals, Reconnect laterals
• Edit: Move drain, Edit drain vertices, Split, Trim drain lines, Extend selected drain
• Delete (red): Erase selected drain, Erase by area, Erase all runs

The tool that is on is highlighted. Right-click a run on the map for the same tools on that run.

• Move the rail: drag it by the grip (the dots in the small pill at its top) or by the empty space between buttons. It stays where you put it; double-click the grip to put it back
• Pin it: click the pin in the same pill to lay the tools along the top of the map; click it again to float the rail back
• Short screen: the rail folds into one Tools button; choosing a tool closes it again

Undo and Redo are the two curved arrows beside the zoom buttons.

Where to find it: bottom-left corner of the map

• Layers: opens Map Layers — the base map, elevation, the analysis layers, soils, your design's colours, reference layers and the land grid, each with an on/off box and a see-through slider. See Analysis Overlays and Base Layers
• Contours: contour lines at the interval you pick, on the active surface. See Terrain Visualization
• Measure & annotate: distance, area and angle, and labels, text, arrows, shapes, legends, north arrow, scale bar and more. See Annotations & Grid Overlay
• GPS: your position on the map. See Navigation & Controls
• GPS survey: record a drain by walking or driving it. See GPS Survey
• Reference overlays: your own images and KMZ files on the map. See Reference Layer Overlays

3D View is at the bottom right of the map once elevation is loaded. See 3D Terrain Viewer.

The Profile Chart

The chart along the bottom shows the ground and your design along the selected run: the elevation profile, the grade line, the min and max depth lines, connections, surface inlets and violations. Hover it for station, elevation and depth. Open or close it with the Profile Chart button at its right end, and drag its top edge to resize it. While a drawing or editing tool is on, the chart tucks away so the map is free for your clicks; the grade tools open it. It shows in the Drainage workspace only. See Grade Analysis & Best Fit.

Where to find it: top bar > Workspace

• Drainage Design: tile and surface drains — the tool rail, the profile chart, culverts, sizing, the simulation, reports and machine files
• Landforming (Beta): the Design tab holds Landforming Design; the tool rail, profile chart and the drainage report and export sections are put away

Switching only shows and hides panels: nothing in your project changes, and both designs stay in the project. The project remembers the workspace it was saved in. Switching puts away any map tool that was on.

Where to find it: top bar > Search locations in… (it names your region, for example Search locations in USA… or in Denmark…)

Prefer a guided walk-through with pictures? See How to: Every tool, by where it lives.

The location search in the top bar finds a town, road or place in the country the app is set to.

Use your device's GPS to track your real-time location on the map - perfect for field surveys and site visits.

The full list is in Keyboard Shortcuts below. Besides Ctrl+K, the one to remember is Esc: it cancels whatever you are doing and closes the active tool, popup or dialog. When in doubt, press Esc.

Efficient ways to navigate during design work:

There are a lot of tools in Geo-Surface Drain Pro. Rather than hunting through panels, press Ctrl+K anywhere in the app and start typing.

How It Works:

1. Press Ctrl+K (or click Find any tool or setting… in the top bar)
2. Type what you're after — "offset", "pipe size", "backup", "contours", "units"
3. Use the arrow keys to move through the results and press Enter, or click a result
4. The app takes you straight to that control, wherever it lives — switching tab or workspace and opening the right panel — and points to it. It never presses the control for you

You don't have to know the exact name. Searching for "parallel" finds Copy offset; "metric" finds the units switch; "wet" finds the wetness layer. You can also filter by category: All, Project, Design, Landforming, Map and Deliver. Press Esc to close.

Choosing a result puts away any map tool you had active, including a drain you had started but not finished, so the next click on the map does what the new tool expects. Just opening the finder and closing it again changes nothing. In the free viewer, a result that belongs to Geo-Surface Pro explains what the full version adds instead of opening.

Shortcut	What It Does
Ctrl+K	Open the tool finder
F1	Explain a tool, setting, or heading: then click the item you want help with
Ctrl+Z	Undo
Ctrl+Y	Redo (Ctrl+Shift+Z also works)
Esc	Cancel whatever you're doing — closes the active tool, popup or dialog
[ / ]	With a run selected, step to the previous or next run on the same main (mains step through the mains). Not while you are typing, drawing or in a dialog
M S L I / M T	While the Draw menu is open on the tool rail: pick Main, Sub-Main, Lateral or Surface Inlet (tile), or Main Drain or Tributary (surface). Enter draws the highlighted type, the arrow keys move between types
Alt+click	While editing drain vertices or the boundary, deletes the point you click; on the profile chart with Guided or Freeform, removes the grade point you click
Double-click	Finish the drain or boundary you're drawing. A drain needs two different points at least 1 m (about 3 ft) apart; a click and a double-click on the same spot creates nothing
Enter	Finish what you are drawing on the map, the same as a double-click: a drain, boundary, cut line, area selection or measurement. Ignored while you are typing in a box
Right-click while drawing	Does nothing: it never places a point, and the browser menu stays out of the way while a tool is active. Use Esc to cancel
Switching stage or workspace	Puts the active map tool away, the same as Esc, so a tool armed on the Design stage cannot edit drains from another one
Click the first point	Closes the boundary you’re drawing (the first point rings green when you’re close enough)
Backspace	While drawing a boundary, removes the last point you placed (Delete also works)
Ctrl+C / Ctrl+V	Copy and paste an annotation while in annotation edit mode
Delete / Backspace	Delete the selected annotation in annotation edit mode

You shouldn't have to leave what you're doing to find out what a setting means.

The "i" Buttons

Settings that deserve an explanation carry a small i beside them. Click one for a plain-language explanation in place — what the setting does, how it interacts with the others, and a worked example with real numbers. You'll find them throughout the drainage settings and the landforming panel. Press Esc to dismiss.

The "?" Buttons

Panel headers carry a ? button that opens this manual at the section covering that panel — no scrolling or searching. The drainage settings popup opens Design Parameters, and the Layers panel opens Analysis Overlays.

Explain Anything on Screen

Press F1, or in Geo-Surface Pro open Help & feedback and choose Pick a control. The cursor changes to a help pointer. Click any sidebar tool, setting, button, or heading and Geo-Surface opens a compact explanation beside it without running the control. From that popover you can open the matching manual section, or in Geo-Surface Pro ask the support assistant for more detail. F1 works in the demo and the free Viewer too. Press Esc to cancel the picker.

24/7 Project-Aware AI Support

Help & feedback gives you an advanced AI support partner inside Geo-Surface whenever you work. It can explain a result, guide a workflow, diagnose a problem, turn an issue into a clear support case, prepare a feature request, or help you contact a person. With your permission it uses the current workspace, available controls, design status, recent actions, warnings, and errors to give advice that fits the project state instead of a generic answer. The AI assistant is part of a Geo-Surface Pro membership: in the demo and the free Viewer the Help & feedback button carries a PRO badge and explains that instead of opening.

The panel tells you exactly what may be shared and asks before including sanitized project context. Field coordinates, raw geometry, elevation rasters, uploads, file names, report branding, and cost values are excluded; a map preview is sent only when you explicitly attach it. AI can make mistakes, so verify decisions that affect field operations.

A support case the assistant drafts for a person states the app version and release, the page (Pro, demo or viewer), your browser, your last 15 actions, the app's own recent warnings and refusal messages (with coordinates, paths, e-mail addresses and file names removed), the ground you are designing on and a count of your runs, and it asks you to reply with a project backup when the problem involves a design. You read and can edit all of it before pressing Send, and if you chose not to share project context only the version, page and step go with it.

The Manual Button

The book button in the top bar opens this guide at any time, and What's New beside it takes you straight to the latest release notes.

Hover Anything

Nearly every button describes itself if you hover over it for a moment. Hovering a drain on the map shows its name, type, pipe size, length, average grade and depth range without you selecting it at all.

Where to find it: Project tab > 1 Define Your Field

Every project starts with the field boundary. It sets the area the elevation is downloaded for, clips the analysis layers to your field, and is the edge the layout tools keep laterals inside. The Project tab works in order: Download elevation for this field stays grey until there is a boundary.

One field per project keeps reports and machine files clean. Soil information for the field is fetched on its own once the boundary is in.

Find your field

Zoom with the mouse wheel, or type a place, road or town into Search locations in the top bar. It searches the country or region the app is set to.

To see field and property lines while you work, open Map Layers and turn on the land grid: PLSS Overlay (townships and sections) in the US, Land Parcels in Canada (quarter sections in Manitoba, Saskatchewan and Alberta; lots and concessions in Ontario). The other regions have no land grid layer.

Where to find it: Project tab > Define Your Field > Upload field boundary

Click Upload field boundary (or drag the file onto it) and pick your file. The boundary appears on the map and the map zooms to it.

Supported files

• Shapefile: a ZIP holding the .shp, .shx, .dbf and .prj files. A field in several parts, or with holes (a pond, a yard), comes in as drawn, each hole with its own part
• KML / KMZ: from Google Earth, a farm-management program or a display export. Every polygon in the file is used, holes included; lines and points in the same file are ignored

Where to find it: Project tab > Define Your Field > Draw field boundary

1. Zoom in until the field edges are clear on the imagery
2. Click Draw field boundary
3. Click each corner of the field in turn, following the edge of the crop. Add extra points along curves
4. Finish by clicking the first corner again (it grows into a green ring when you are close enough), pressing Enter, or double-clicking
5. Wrong corner? Backspace (or Delete) removes the last one. Esc cancels the whole outline

The finished outline shows the field area. An outline with no area (every point in one straight line) is not accepted: draw at least three corners that are not in a line. A very small field is fine. The boundary does not need to be perfect: you can fix it with Edit Boundary.

Where to find it: Project tab > Edit Boundary (appears once a boundary exists)

Reshape a boundary without drawing it again:

• Extend: draw a shape overlapping the boundary to add that ground to the field
• Clip: draw a shape over the part to cut off
• Hole: draw a shape inside the field to leave out a yard, a wooded area or a wetland
• Vertex Edit: drag a corner to move it, click an edge to add a corner, Alt-click a corner to delete it

Undo / Redo (Ctrl+Z / Ctrl+Y) step through your edits and Esc cancels the tool. Click Apply to make the edited outline the field boundary, or Cancel to keep the original. Export Boundary Shapefile saves the boundary, under the Field Name you type, for use in other programs.

There is no fixed acreage limit, but one elevation download is held to about 3,000 cells along its longest side so your browser stays responsive. A full section (640 ac) still downloads at 1 m; a much larger area is offered only at coarser resolutions, and the download dialog tells you to draw a smaller boundary if you want 1 m detail. See Get Elevation Data.

Geo-Surface works in one region at a time. The region decides where elevation is downloaded from, the units a new project starts in, and the rainfall and soils sources.

Which region opens. Geo-Surface Pro, the demo and the free Viewer each have one address, and each opens in your region without asking:

1. a link that names a region (for example one from the coverage page) opens in that region;
2. otherwise the region you used last on this computer;
3. otherwise, when you are signed in, the region of your membership;
4. otherwise the country your browser is set to (its language and time zone; nothing is looked up online);
5. only if none of these says where you are does Geo-Surface show the region list.

If you already use Geo-Surface in the United States or Canada, nothing changes: it opens straight into your region as before.

Switching region. The region button at the top of the window, beside the Geo-Surface name, shows the region you are in (for example US or UK). Click it and pick another region: the page reloads in that region and remembers it next time. Search all regions… at the foot of the list opens the full region list with a search box. The region list is grouped (United States, Canada, United Kingdom, Europe, Australia & New Zealand, Somewhere else) and each entry says where its elevation comes from and how fine it is. A project remembers its own region: opening it in another region offers to switch.

• United States: elevation from USGS 3DEP (1 m LiDAR where it is published, 10 m elsewhere), NOAA rainfall entered by hand, SSURGO soils. Heights are NAVD88, and the report says so.
• Canada: elevation from NRCan HRDEM (1 m LiDAR where it is published), Environment Canada rainfall stations, Canadian and global soils. Heights are CGVD2013, and the report says so.

  Quebec. When the map is in Quebec, Map Layers > Map foundation adds three layers, all off until you turn them on, and place search also asks the province’s address register:

  • Watercourses (Québec): the streams and ditches of the Quebec high-resolution hydrographic network (GRHQ-HR), mapped from LiDAR by the Quebec ministries of Natural Resources and Forests (MRNF) and of the Environment (MELCCFP). Zoom in to see them. Click a line for its type as the network classifies it (for example Watercourse or Agricultural drainage), whether it is permanent or intermittent, its Strahler order and the area that drains to it, in acres or hectares. The type is the map’s classification, not a legal status.
  • Agricultural zone (Québec): the agricultural zone of the Commission de protection du territoire agricole du Québec (CPTAQ), lightly shaded with its boundary drawn. Click the map to see whether a point is inside it; the answer is the CPTAQ’s zone transposed onto the cadastre.
  • Declared field outlines (FADQ): the farm field outlines declared to La Financière agricole du Québec (BDPPAD 2026), shown from zoom 13. Click a field for its area and, when the farm declared it, Declared tile-drained: yes or no (what was declared to FADQ; no line when nothing was declared), and choose Use as field boundary to start a project from it. A boundary taken from an outline carries the FADQ credit into the PDF report, and keeps it when the project is saved and reopened; drawing or loading another boundary removes it. You are responsible for checking that the outline matches your field.
  • Adresses Québec: the provincial address register answers place searches in Quebec alongside OpenStreetMap, so a rural address on a rang (for example 6210 rang Saint-André, Saint-Hyacinthe) finds the farm. Each result says which source found it.

  All four are published under CC BY 4.0. The map, map exports and report maps credit the layers while they are shown.

  What the sources say about watercourses, as they state it:

  • Riparian strips: in farmland, a strip of vegetation at least 3 m wide is kept along a lake or watercourse, measured from the high-water line, with at least 1 m of it on the flat above the top of the bank when the top of the bank is less than 3 m from that line; along a ditch the strip is 1 m. Sources: UPA Montérégie, Aide-mémoire bandes riveraines; MAPAQ, Bandes riveraines en milieu agricole (2014).
  • Who decides: since 2006 the regional county municipality (MRC) has jurisdiction over the watercourses of its territory, including the free flow of their water (Loi sur les compétences municipales, sections 103 to 110). MAPAQ’s 2025–26 fiche on levelling and subsurface drainage states that drain outlets built in a watercourse generally need an authorization from the municipality or the MRC.
• United Kingdom (England and Scotland): in England, elevation comes from the Environment Agency 1 m LiDAR, which covers almost all of England. In Scotland it comes from the Scottish Remote Sensing Portal LiDAR (0.5–1 m), which covers part of Scotland today and the whole country by 2027: show the LiDAR Coverage layer to see where it is published. Geo-Surface picks the right source from where your field is. Wales and Northern Ireland have no open LiDAR service Geo-Surface can read, so there you bring your own elevation as in International. Heights are above Ordnance Datum Newlyn (ODN), new projects start in metric, files in British National Grid (EPSG:27700) are read directly, rainfall is entered by hand and soils come from SoilGrids. The report credits the data: it contains public sector information licensed under the Open Government Licence v3.0.
• New Zealand: elevation from the LINZ national 1 m LiDAR DEM wherever New Zealand has been surveyed by LiDAR, which covers nearly all the lowland farm regions. Heights are NZVD2016, and files in NZTM2000 are read directly. Where a field has no LiDAR, nothing is loaded and you are told so; set the base layer to LiDAR Coverage (LINZ 1 m) to see where it exists. New projects start in metric, rainfall is entered by hand, and soils come from the global SoilGrids map.
• Australia: elevation from Geoscience Australia's national 5 m LiDAR DEM where it is available (the coast, the Murray-Darling floodplains and towns; several irrigation districts, including the Murrumbidgee and Goulburn-Murray, are not covered). This is coarse 5 m elevation: fine for surface drainage planning and a first look, too coarse for tile design. For tile, replace it with your own RTK survey or 1 m LiDAR under Other elevation sources. The status line and a message after each download say 5 m national LiDAR (coarse). Heights are AHD; files in GDA2020 or GDA94 MGA zones and latitude/longitude are read directly. Set the base layer to LiDAR Coverage (GA 5 m) to see where it exists. New projects start in metric, rainfall is entered by hand, and soils come from SoilGrids.
• France: elevation comes from the IGN LiDAR HD terrain model (0.5 m). Where LiDAR HD is not published yet, Geo-Surface fills the gaps from IGN RGE ALTI 1 m and the status line says so; RGE ALTI is coarser in places, so check the status line before designing. Heights are NGF-IGN69, files in Lambert-93 (EPSG:2154) are read directly, and the report credits IGN under the Licence Ouverte 2.0.
• Switzerland: elevation comes from swisstopo swissALTI3D (0.5 m), which covers the whole country and Liechtenstein. Heights are LN02, files in LV95 (EPSG:2056) are read directly, and the report credits swisstopo.
• Czechia: elevation comes from the ČÚZK DMR 5G terrain model, built from airborne LiDAR and served as a 2 m grid, covering the whole country. Heights are Bpv (Baltic Vertical Datum – After Adjustment), files in S-JTSK / Krovak East North (EPSG:5514) are read directly, and the report credits ČÚZK under CC BY 4.0.
• Finland: elevation comes from the National Land Survey of Finland 2 m laser-scanned terrain model, covering the whole country. It is read from a research mirror without a service guarantee: if it does not answer and you have your own free National Land Survey API key, enter it under Drainage settings › Data sources and Geo-Surface reads the survey’s own service instead. Heights are N2000, files in TM35FIN (EPSG:3067) are read directly, and the report credits the National Land Survey of Finland under CC BY 4.0.
• In France, Switzerland, Czechia and Finland new projects start in metric, rainfall is entered by hand, soils come from SoilGrids, and a field outside the country is refused rather than given made-up ground.
• Netherlands: elevation from AHN, the national 0.5 m LiDAR that covers the whole country. Heights are NAP, so polder fields read below zero, as they are. AHN leaves no ground where the laser did not reach it: narrow gaps such as field ditches and tree rows are filled from the ground beside them, while buildings, farmyards and open water stay empty. Files in RD New (Amersfoort) are read directly.
• Belgium (Flanders): elevation from the Digitaal Hoogtemodel Vlaanderen II, 1 m LiDAR covering all of Flanders and Brussels. Wallonia is not covered yet: a field there is refused with a message rather than loaded with false ground. Heights are TAW (Ostend), and files in Belgian Lambert 72 or Lambert 2008 are read directly.
• Germany (North Rhine-Westphalia): elevation from the Geobasis NRW 1 m terrain model, which covers the whole state. Heights are DHHN2016, and files in ETRS89 / UTM zone 32N or the older Gauss-Krüger zones 2 and 3 are read directly. The rest of Germany is not covered yet.
• Denmark: elevation from the Danish Elevation Model DHM/Terrain (Klimadatastyrelsen), 0.4 m LiDAR covering the whole country, delivered at the resolution you pick (1 m for most fields). Heights are DVR90. Files may also be in ETRS89 / UTM zone 32N.
• Norway: elevation from Kartverket's national terrain model (DTM1), 1 m LiDAR covering the whole country. Heights are NN2000. Files may also be in ETRS89 / UTM zone 33N or 32N.
• Estonia: elevation from the Land and Spatial Development Board (Maa- ja Ruumiamet), 1 m LiDAR covering the whole country. Heights are EH2000. Files may also be in the Estonian national grid (L-EST97).
• International (bring your own elevation): for fields anywhere else. Geo-Surface does not download elevation here: you bring it. Upload a GeoTIFF, import RTK or survey points, or import an existing design under Other elevation sources. New projects start in metric, rainfall is entered by hand, and soils come from the global SoilGrids map. Every design, sizing, report and export tool works on the surface you bring.

In the Netherlands, Belgium (Flanders) and Germany (North Rhine-Westphalia) new projects also start in metric, rainfall is entered by hand and soils come from SoilGrids.

In Denmark, Norway and Estonia new projects start in metric, rainfall is entered by hand and soils come from the global SoilGrids map. The LiDAR Coverage base layer shows where the national survey covers; a field outside it (across a border or out at sea) is refused rather than filled with made-up ground. The PDF report credits the elevation source as its licence asks and names the height datum.

Choosing a region: a link that names a region opens in it. Otherwise Geo-Surface opens in the region you used last or, the first time, in your own country, read from your browser; when it cannot tell (or a link names a region this version does not have), a Choose your region page lists every region with where its elevation comes from; pick yours. The region button at the top of the window switches region. Each project remembers its region: opening a project from another region asks to switch to it.

Starting drainage values: outside the United States and Canada, a new design starts from values that are typical for tile drainage in that country instead of US numbers: for example 16 m lateral spacing and 1.0 m depth in Denmark, 11 m and 0.9 m in the Netherlands, or 20 m and 0.75 m in the United Kingdom, along with that country's usual minimum grade, lateral size and drainage coefficient. Drainage settings shows them at the top of Tile design (Regional starting values for … (typical local practice)), with a Reset to regional values button that puts them back in the fields; nothing is saved until you click Save defaults. They are starting points, not a design for your field: adjust spacing and depth for your soil (the soil suggestion row helps), and widen the lateral spacing if you are pulling mole drains across the laterals. The settings you save are kept separately for each region, so your values in one country never become the starting values in another. A project you open always uses its own saved values.

Coordinate systems: in every region, any file that names its coordinate system is placed for you: latitude/longitude (WGS84), Web Mercator, UTM, the region's national grid, US State Plane (metres or US survey feet), Canadian MTM (for example MTM zone 8 in southern Quebec) and most other EPSG systems. NAD83 in all its versions (HARN, 2011, CSRS) is read as WGS84, as for UTM. When a file does not say which system it uses, you are asked; the list there offers the State Plane or MTM zone at your field, and you can search by EPSG code or name. Australian files in GDA94 (latitude/longitude or MGA94 zones) are moved the 1.5 m to GDA2020 for you, and ETRS89 UTM files that put the zone number in front of the easting (EPSG:4647, common in Germany) are read as well.

Where to find it: Project tab > 2 Get Elevation Data > Download elevation for this field (Recommended)

Once the field boundary is in, click Download elevation for this field. The elevation comes from the public LiDAR of your region: USGS 3DEP in the US, NRCan's HRDEM in Canada, the national survey elsewhere (see Regions). In the International region there is no download: bring your own elevation.

1. The Choose elevation resolution window lists the resolutions offered for your area, each with its size in cells and an approximate download size. The sensible one is marked Recommended (1 m for a normal field). Nothing finer than the elevation your region publishes is offered: Australia's 5 m data starts at 5 m, and a country that publishes finer than 1 m offers that too, marked as the data's own resolution. In Canada, a field that lies only in LiDAR projects published at 2 m starts at 2 m, and the window says so
2. Click Fetch. Most fields take 10 to 30 seconds
3. The field turns into a colour elevation map with hillshade, low ground purple and high ground yellow, and the heights in the legend at the top right of the map

One download is held to about 3,000 cells along its longest side so your browser stays quick. A full section (640 ac) still comes at 1 m; for a much larger area only coarser options are offered, and the window says to draw a smaller boundary for 1 m detail.

Check before you fetch: in Map Layers, set the base layer to LiDAR Coverage (1 m DEM index) in the US to see where 1 m LiDAR is published, or LiDAR Terrain in Canada.

Where to find it: Project tab > 3 Create Analysis Layers, the Active DEM line under the button

The line says what you actually got, not what you asked for, with the cell size measured on the ground. The PDF report names the same source.

• “1 m LiDAR · <project name>” (US): what you want. In the US the app reads the published 1 m LiDAR project tiles directly, and fills any cell they miss from the USGS elevation server; when that share is noticeable the line adds it, for example (4% filled from the national DEM)
• “USGS 11 m national DEM (no 1 m LiDAR published here)”: no 1 m LiDAR exists for the field yet. You can still lay drains out, but check grades on the ground, or use an RTK survey as the ground (below)
• “USGS 8 m national DEM (1 m LiDAR available — re-fetch at 1 m)”: 1 m data exists, so fetch again at the resolution named. If the area is too big for that, the line asks you to draw a smaller boundary instead
• “… (1 m LiDAR archive not reachable …)”: your connection to the 1 m archive dropped during the fetch and the elevation server answered instead. Fetch again later
• “Canadian HRDEM LiDAR” (Canada). Where Canada has no LiDAR, the app says so instead of loading coarser ground
• “… · published at 2 m here” (Canada): you asked for finer than 2 m, but the LiDAR under the field is published at 2 m only, so the 2 m LiDAR was loaded and a message says so. Only when 2 m has no elevation either do you see No LiDAR coverage in the area you drew
• Elsewhere the line names the region's own source, for example “1 m LiDAR · Danish Elevation Model DHM/Terrain” in Denmark or “5 m national LiDAR (coarse) · Geoscience Australia” in Australia
• “… · partial (N % covered)”: the elevation covers most of the field but not all of it, and a message says how much. If less than half the field has elevation, nothing is loaded and you see No LiDAR coverage in the area you drew (US: No elevation coverage in the area you drew)

In the US, a drain that runs past the edge of your downloaded surface takes the ground beyond the edge from the same 1 m tiles. Where no 1 m tile exists there, those profile points come from the elevation server instead; they are drawn orange on the profile and a notice says where they came from.

The elevation comes from government servers, and now and then they are slow or down. The app tries three times and also tries the same LiDAR from its public cloud archive. Your boundary and design are never affected.

• Backup Elevation Source Used: the server did not answer (or had no elevation for most of the area), so the same government LiDAR was read from the public archive. Click OK. If the backup could only deliver coarser cells, the box says so: fetch again later for the full resolution
• Coarse Elevation Data: the elevation loaded but is coarser than you asked for, with the delivered and requested cell sizes. Small drainage features may be smoothed out
• No LiDAR coverage in the area you drew (US: No elevation coverage in the area you drew): the server and the public archive both answered, with no elevation for the field. The field is outside the surveyed area; this is not an outage, and trying again will not change it
• Government Elevation Server Not Responding: nothing answered and no elevation was loaded. Click Keep Trying (3 more attempts) or Cancel for Now and come back later. Outages usually clear within minutes; scheduled maintenance within a few hours

Where to find it: Map Layers > Elevation Data > HD Elevation

HD Elevation combines elevation colours with hillshade relief. Pick a colour scheme from Color Ramp under the layer (Spectral is the default); the colours stretch to your field's own height range, so even flat ground shows variation, and your choice is remembered. Turn the layer off, or fade it with its slider, from the same panel.

Spot heights: click anywhere on the map for the elevation at that point, in your units. With no elevation loaded, the app asks the government elevation service and names the source under the number.

Where to find it: Project tab > Get Elevation Data > Other elevation sources, or an existing design > Elevation only

Government LiDAR is right for planning, but it was flown years ago. Use your own elevation when the field has been levelled or ditched since, when there is no 1 m LiDAR where you farm, or when the machine will install to grade. Everything under Elevation only replaces the ground and never touches your runs. You do not need a field boundary first: if the project has none, Geo-Surface offers one from the area the file covers (see No boundary yet below). Every file is read on your own computer: nothing is uploaded, and there is no practical size limit.

• Upload Elevation Points / Import Survey Shapefile (.zip): a zipped point shapefile (.shp, .shx, .dbf and .prj). Placed from the .prj in any coordinate system it names (latitude/longitude, UTM, State Plane, MTM, your national grid and most other EPSG systems); NAD27 is refused by name
• Import Survey CSV/XYZ: a CSV, TXT or XYZ point file in latitude/longitude. For a file in UTM, use Use an RTK survey as the ground instead
• Import AGS surface: brings a land-forming design (or another AGS elevation file, such as an AGPS survey) back as the ground, so tile is designed to the finished grade
• Upload Your Own GeoTIFF: a finished elevation grid, such as a drone surface (rules below)

Point files: columns and units

A point shapefile shows Select Elevation Column: pick the height field (or the Z of a PointZ file), then the units. A CSV shows Map survey columns: Latitude, Longitude and Elevation, guessed from the header row, and feet or metres. Units are filled in only when the file states them; otherwise you must choose, so a metric survey is never read as feet by default. AGS files need no mapping.

How the surface is built

• Every shot is checked first. A lone shot more than 0.5 m (1.6 ft) off the ground its neighbours describe (a bumped rod), and shots at the same spot whose heights disagree by more than 5 cm (2 in), are listed. Each listed shot is kept unless you tick Drop; a ditch or bank surveyed with several shots is not listed
• The surface passes through every shot you kept, with straight-line blending between shots and no smoothing, so a surveyed ditch keeps its bottom and banks
• Nothing is guessed: ground beyond your outer shots, or across a gap wider than the survey spacing, is left empty, and the covered area is outlined on the map. If shots were left out, a notice says how many and why
• The Active DEM line reads Survey points (CSV), (shapefile) or (AGS) with your file's name, and the surface is saved in the project backup

GeoTIFF rules

• One elevation band, in a coordinate system the file names. Web Mercator (EPSG:3857) loads as it is; a file in any other coordinate system it names (latitude/longitude, UTM, US State Plane in metres or US survey feet, Canadian MTM, your region's national grid or another EPSG system) is placed on the map at its own resolution for you. A file with no coordinate system, or one that needs a grid shift Geo-Surface does not include (NAD27), is refused with its coordinate system named, and the elevation you had stays in place
• Heights in metres, or in feet / US survey feet when the file says so; those are converted for you
• A file with no usable heights is refused with the reason

No boundary yet: use the area the file covers

When the project has no field boundary, the file loads as usual and a Field boundary card asks Use the area this file covers as the field boundary?. The proposed outline is drawn on the map with a dashed line and its area is on the card.

• A GeoTIFF clipped to the field (cells outside the field are empty, the file's NoData value): the outline of the cells that hold elevation, following the clipped edge to within about one cell. Small gaps inside the field (under an acre) are filled; a separate patch of cells away from the field is left out. A file with no empty cells is its whole rectangle, and the card says so
• A survey (CSV/XYZ, point shapefile or AGS): the area your shots cover, drawn half the shot spacing inside the outer shots, so it never includes ground that was not surveyed. It is smaller than the field by about one shot spacing all round
• Use it makes it the field boundary, exactly like a drawn one: change it with the boundary tools, and it is saved with the project. One Undo takes it away again. I’ll draw my own keeps the file and leaves the boundary for you to draw or load
• No outline is offered for a survey of fewer than 20 shots or one whose shots lie along a single line; a notice asks you to draw the boundary
• A project that already has a boundary is not asked; data outside the boundary stays on the map as before
• The outline only shows where the file has data. You are responsible for checking that it matches the field

Common problems

• No boundary offered after a survey import: the survey has fewer than 20 shots, or its shots lie along one line; draw the field boundary or load a boundary file
• “Fewer than 3 valid lat/lon points” or most rows ignored: almost always a CSV in UTM or state plane read as latitude/longitude, or swapped latitude and longitude columns
• “No numeric fields found in the shapefile”: the heights are stored as text; make a numeric field in QGIS and re-save
• Heights off by a factor of about 3.3: feet read as metres or the other way round; choose the right unit and import again

Where to find it: Project tab > Get Elevation Data > Other elevation sources, or an existing design > Use an RTK survey as the ground (the teal card)

The machine installs from the ground as your RTK receiver measures it today. This card takes the survey straight from your display or data collector, in two cases: start a project where there is no usable LiDAR, or replace the LiDAR under a design you already drew. Only the ground changes: no run is drawn, moved or deleted.

1. Choose the survey

Click Choose survey files / ZIP (or Choose folder when the display saved a whole folder). It takes:

• Trimble: an AgGPS folder or a FieldLevel.xml exported from the display. If the file carries a field boundary and the project has none, that boundary is used
• Ag Leader: a display export (.agdata) or an SMS export (.agsetup). The heights are taken as the display recorded them, so there is nothing to choose. A file with several fields lists them, largest first; very small recordings (a test pass) sit behind Show all
• Point shapefile: the SHP, DBF and PRJ together, or a ZIP of them
• CSV / TXT points in latitude/longitude, UTM, Web Mercator or another coordinate system you name (next step)
• AGPS Pipe Pro .svy (its .nez and .lla companions also work). The job, rod length and UTM zone are read from the file. Its heights are ellipsoid heights in feet, not sea-level heights, so tie it to a reference point (step 3) when matching a LiDAR design

2. Survey columns and units (CSV / TXT)

Confirm the Longitude / Easting column, Latitude / Northing column, Coordinates (latitude/longitude; Web Mercator; UTM easting / northing with UTM zone, Datum WGS84, NAD83, ETRS89 or GDA2020, and Coordinate units; or Another system (State Plane, MTM, EPSG code)…, which searches by name or EPSG code and sets feet units for a system defined in feet), the Elevation column and the Elevation units (Metres, Feet (international) or US survey feet), then click Use these survey heights. The zone is taken from the file when it names one, otherwise from your field. If the survey lands more than 1 km from the field, the app says how far and in which zone it was read, and waits for you: a wrong zone moves a survey hundreds of miles.

3. Match heights at one reference point (existing design only)

A design drawn on LiDAR and a survey have different height references, so they are lined up at one stable surveyed point. Under Match heights at one reference point, click Choose reference on map and click a shot that will not move (a benchmark), click Sample planning ground at this point, check the survey height against the planning-ground height, and tick the confirm box. The pipes do not move, and the same point becomes the master benchmark in the machine files.

4. Check the listed shots

The same check as for point files (above). Tick the shots to leave out and click Build surface. Your choice is saved with the project, so a rebuild uses the same shots.

5. Build, review and apply

• No design yet: the button reads Build RTK ground. The survey becomes the ground straight away, and analysis layers, contours and drawing all work from it. Show survey coverage outlines the surveyed area; nothing beyond your outer shots is guessed
• Existing design: click Preview design on RTK survey. A review opens on the Design tab, Switch the design to the surveyed ground, with a summary and a Run-by-run comparison (click a run to see the surveyed ground and re-fitted grade on its profile). Nothing has changed yet. Then choose:
  • Re-fit the pipes to the surveyed ground: Best Fit works out each run's grade again with your depth and grade settings; Guided and Freeform grades stay as drawn
  • Keep the pipes exactly as designed: pipe elevations stay as drawn and only the cover depth is re-checked

Afterwards Designing against on the Design tab reads RTK survey · <file name>, the Active DEM line says the same, and the report names the survey as its elevation source. Check the run finder for violations as after any change. The LiDAR version of the project is kept: Download original planning project saves it.

Machine delivery changes too. On the Deliver tab, Send the design to the machine now says the design is built on the applied RTK survey: installable files are no longer marked Not recommended here, and a full installation package is marked Recommended. See Exports.

Surface options (cell size, survey pass spacing) are worked out from the survey; enter your own only if you need to.

Where to find it: Project tab > Get Elevation Data > Other elevation sources, or an existing design > Open a design made on another system (the navy card, Complete design + its survey)

Brings in the runs with their grades and pipe sizes and the survey they were designed on, as an editable project you can review, change and deliver again. Click Choose design files / ZIP or Choose design folder.

• Trimble WM-Drain: an AgGPS folder or FieldLevel.xml with designed runs. The file gives each run's pipe diameter but not its wall type or perforation, so those come from your drainage settings; change any run afterwards
• Ag Leader Intellislope: a tile plan (.agsetup, or .agdata from a display) with designed runs. Each run's ground profile, depth and grade settings and pipe size come across, and the field boundary in the file becomes the project boundary. A file with only surveys belongs on the RTK survey card instead

With project folders on, the design opens as a new project and the current one is not changed. With them off it replaces the open project (the card says so): save a backup first. The file is checked before anything happens, so a refused file or a cancel leaves your project as it was. Surface options › Cell size sets how finely the survey becomes ground (left on Automatic it is 2 m, coarser only when a very large survey needs it); the card says which size was used.

Where to find it: Project tab > 3 Create Analysis Layers > Create Drainage Layers

Once the elevation is in, click Create Drainage Layers. The app works out where water runs, where it collects, how wet each part of the field stays and which ground drains to which outlet. It all runs in your browser: nothing is uploaded and there is no queue. Typical fields finish in 5 to 30 seconds.

1. Have a field boundary and elevation loaded (downloaded, your own GeoTIFF, or a survey). The button stays grey until then, and the line under it says No elevation data loaded
2. Where a road or lane crosses a ditch or draw, mark and carve the culverts first (below)
3. Click Create Drainage Layers. The Processing Drainage Analysis window names each step, with an Elapsed counter and Typical: 5-30s, and says so if a field takes longer than usual. You can cancel at any time
4. When it finishes, Flow Lines and Ponding Predictor are on; the other layers are one click away in Map Layers > Analysis Layers

If something goes wrong, the window stays up with The analysis didn't finish and the reason, and offers Close or Try again.

Ponding Predictor, Ponding after rain and Depressions are clipped to the field boundary. Flow lines carry on beyond it so you can see where water enters and leaves the field. All layers are saved in the project backup, and anyone you share the project with can view them in the free viewer (which cannot create them).

Where to find it: Project tab > Mark Culverts (optional), between Get Elevation Data and Create Analysis Layers

In LiDAR a road or lane reads as an unbroken ridge: the culvert under it is invisible, so the model dams water against the road and every flow path below it is wrong.

1. Click Mark culvert, click the ditch on one side of the road and then on the other (inlet to outlet), then click Mark culvert again when you are done. Each culvert gets a tag (C1, C2…) and a row in the list, with buttons to zoom to, edit or delete it
2. Click Carve culverts into elevation. A thin channel is cut through each culvert, the list says how many are in the carved surface, and the app works on the carved elevation from then on (the Active surface box at the top of the sidebar names it, Burned Elevation (culverts)). Only the culverts are carved: your surface drains go into the elevation only when you click Burn drains into surface (Design tab), and once they are in, marking or deleting a culvert keeps them there
3. Click Create Drainage Layers so the layers use the carved surface

Import culverts… reads a shapefile or GeoJSON of lines or points, and you match your own columns for diameter, material and tag. A damaged shapefile record, or a file whose shape and attribute counts disagree, stops the import and says which. Hide on map hides the culvert lines without undoing the carve; Clear removes every culvert and takes them out of the elevation: you are back on the original elevation, or on the surface with only your burned drains when you had burned them in. Hold the mouse over a culvert to see its length, drop, peak flow and a recommended size.

If the analysis shows water piling up against a road you know drains, a missing culvert is nearly always the reason.

Where to find it: Map toolbar (bottom left of the map) > Map Layers > Analysis Layers. Each layer has a checkbox and a see-through slider.

Reference layers allow you to overlay custom images and vector data onto your project map. These can be scanned maps, photos, screenshots, KML files, or shapefiles that provide additional context for your drainage design.

Common Use Cases:

• Prior Designs: Overlay existing drainage maps to reference past installations
• Utility Locations: Import utility maps showing buried cables, pipelines, or water lines
• Soil Maps: Layer EC maps, soil survey data, or yield maps for reference
• Field Photos: Georeference aerial photos or drone imagery from other sources
• Planning Documents: Import survey drawings, engineer plans, or CAD exports
• Property Boundaries: Load parcel boundaries, easements, or legal descriptions

Raster Image Formats:

• JPG/JPEG: Photos, scanned maps, screenshots (manual georeferencing)
• PNG: Graphics, screenshots, exported maps (manual georeferencing)
• BMP: Windows bitmap images (manual georeferencing)
• Image + world file (BMP + BPW, JPG + JGW, PNG + PGW, .wld / .tfw): placed automatically. Select the picture and its world file together (Ctrl-click in the file dialog, or drop both), or zip the two. The coordinate system comes from an EPSG= line in the world file (AGPS files carry one) or a .prj beside it; otherwise you are asked once which system it is in: UTM (the zone under the map already filled in), latitude/longitude, Web Mercator, or any other system found by EPSG code or name (State Plane, MTM and so on).
• GeoTIFF: Georeferenced images with embedded coordinate data (auto-placed)
• MrSID (.sid): The tool recognises the format and provides conversion guidance; convert to GeoTIFF before loading because browsers cannot decode MrSID directly

JPG, PNG, and BMP images require 4-point manual placement to position and orient them on the map. GeoTIFF files are placed automatically using the coordinates stored inside the file — nothing to line up by hand.

Vector Data Formats (auto-loaded, no placement needed):

• KML: Google Earth files with points, lines, or polygons
• KMZ: Compressed KML files. A picture laid over the map in the file (a Google Earth image overlay, or the KMZ map package exported from Geo-Surface) loads as a reference image where the file places it
• Shapefile (ZIP): Zipped folder containing .shp, .dbf, .shx files. Lines load as lines and points load as points — one map feature per record in the file
• DXF: CAD drawings imported through the same Reference overlays button (Beta)

KML and KMZ are latitude / longitude (WGS84, EPSG:4326). A shapefile is placed from its .prj in any coordinate system it names (UTM, State Plane, MTM, your national grid and most other EPSG systems); without a .prj it must be latitude / longitude. A DXF asks for its coordinate system and units.

Where to find it: map toolbar (bottom left of the map) > Reference overlays (the last button)

1. Click Reference overlays to open Load Reference Data
2. Drop your file (or a picture and its world file together) in the box, or click Browse Files

The tool recognises the file type for you:

• GeoTIFF (.tif, .tiff): Placed on the map at the correct position automatically
• Image with its world file (.bmp + .bpw, .jpg + .jgw, .png + .pgw, or the two zipped): Placed automatically; you are asked for the coordinate system only if the world file does not name it
• Other images (.jpg, .png, .bmp) on their own: Opens the manual placement workflow
• Vector data (.kml, .kmz, .zip, .dxf): Loads through the same unified picker and zooms to the features
• Pictures inside a KML / KMZ (image overlays): Placed automatically at the corners the file gives them, turned if the file turns them. A file with several pictures loads each one, and a file with both pictures and features loads both. A message lists what was loaded and anything that was not, with the reason

You can add up to 15 reference images per project — that limit covers GeoTIFFs, hand-placed JPG/PNG/BMP images and pictures from a KML or KMZ together. Each one is placed independently, so you can build up several overlays on the same field. Once you reach fifteen, the app asks you to delete one from the Layers panel before adding another. The features in KML, KMZ, shapefile and DXF layers are not counted against that limit — load as many as you need. The dedicated Reference overlays button is the single import entry point; the Layers panel remains the place to manage visibility, opacity, and deletion.

Reference layers are saved inside your project backup and come back when you reopen the project. A project with no boundary yet opens on its reference layers, so an overlay loaded first is also where the map goes until you outline the field. To remove one, open the Layers panel and click the trash icon beside it.

GeoTIFF files contain embedded coordinate metadata that allows the application to automatically place them at the correct position on the map — no manual georeferencing required.

How It Works:

1. Click Reference overlays on the map toolbar
2. Upload a .tif or .tiff file
3. The image is parsed, georeferenced, and placed on the map automatically
4. The map zooms to fit the image extent

Supported Image Types:

• RGB / RGBA: Color images (aerial photos, satellite imagery, scanned maps)
• Single-band (grayscale): Automatically rendered with min/max contrast stretch

Supported Coordinate Systems:

• Latitude / longitude — WGS84 (EPSG:4326) and NAD83 (EPSG:4269 and EPSG:4617)
• Web Mercator (EPSG:3857)
• UTM zones — WGS84 (EPSG:326xx / 327xx) and NAD83 (EPSG:269xx), converted for you
• US State Plane, Canadian MTM, your national grid and most other EPSG systems, converted for you

If the app can't read the coordinate system (NAD27, for example, needs a grid shift Geo-Surface does not include) it tells you so and asks you to re-save the file — nothing is placed in the wrong spot silently.

If a GeoTIFF carries no location information at all, the app will say so and suggest saving it as a JPG or PNG and placing it by hand instead.

When you upload a JPG, PNG, or BMP image, a split screen opens: your image on the left, a map preview on the right. Each image you place is added as its own layer, so you can build up several overlays on the same field.

Step by Step:

1. Click 4 Reference Points on the Image

   Click identifiable features in the image such as:

   • Field corners or property corners
   • Road intersections
   • Building corners
   • Fence posts or utility poles
   • Any clearly visible landmark

   Important: Points do NOT need to be at the image corners. For scanned maps with white borders, click features inside the map content itself. Rotation and scaling are worked out for you.

2. Click the Same Locations on the Map

   For each point you clicked on the image, click the same real-world location on the map preview. The map starts centered on your current project area.

   As you place points, numbered markers (1, 2, 3, 4) appear showing your selections.

3. Preview the Placement

   After you place all 4 pairs, the app works out the rotation, scale and position, then shows the image on the map preview so you can check it.

   Review the placement. If the alignment isn't right, click Reset Points and try again with different reference points. If your four points sit in a straight line the app will tell you and ask for a better spread.

4. Add to Map

   Once satisfied with the preview, click Add to Map. The georeferenced image is added to your project as a semi-transparent overlay (85% opacity).

Tips for Best Results:

• Spread Points Out: Choose reference points spread across the entire image area, not clustered in one corner
• Use Precise Features: Sharp corners and intersections work better than vague features
• Zoom In: Pan and zoom the map preview to click reference locations as precisely as possible
• Don't Line Them Up: Four points in a straight line can't define a placement — spread them like the corners of a shape
• Check Scale: After georeferencing, verify distances roughly match reality using the map's scale

Vector data loads instantly without manual georeferencing. The system:

1. Reads the features from the file
2. Draws them as a new layer and zooms the map to fit them
3. Adds the layer to Map Layers > Reference Layers

Shapefile Requirements:

When uploading shapefiles, ensure your ZIP file contains at minimum:

• .shp: Main geometry file (required)
• .dbf: Attribute data file (optional but recommended)
• .shx: Shape index file (optional)

A shapefile draws as the shapes it actually holds: lines load as lines and points load as points, one map feature for every record in the file.

• Polylines: each run stays its own line, so a 109-run tile layout exported from another design program draws as 109 separate lines. A record made of several parts stays one feature
• Points: drawn as small orange dots — survey points, inlets, or whatever else the file marks
• Polygons: one outline per record, with any holes cut out of it

Elevation (Z) and measure (M) shapefiles load fine — the extra values are ignored, the positions are not. A shape type that cannot be drawn on a map, such as a MultiPatch mesh, is named in a message rather than loaded as something it is not.

KML/KMZ Features:

KML imports preserve:

• Styles: Line colors, fill colors, widths
• Names: Feature labels and descriptions
• Multiple Features: All points, lines, and polygons in the file
• Pictures: each image overlay becomes its own Ref Image at the box the file gives it, and is saved with the project like any other reference image. Load the KMZ map package exported from Geo-Surface and the map picture sits exactly where it was exported

A picture must be inside the file: a KMZ carries its pictures with it. A KML that points to a picture saved beside it, or to a picture on the web, loads its features and lists that picture as not loaded; load the KMZ instead. You are responsible for the accuracy of imported data.

Where to find it: map toolbar > Layers > Reference Layers (the last group)

Each overlay gets its own row, named in the order you added them: Ref Image 1, Ref Layer 2 and so on (an image is a Ref Image, KML, KMZ, shapefile and DXF layers are a Ref Layer).

• Show or hide: tick or untick the row.
• Opacity: a reference image has its own slider; drag it to fade the image against the map underneath. The setting is saved with the project. Vector layers have no slider.
• Delete: click the red trash button at the end of the row; the confirmation names the file.

Overlays sit under the elevation colours: switch HD Elevation off to see them clearly.

Multiple Reference Layers:

You can load multiple reference layers simultaneously. For example:

• Utility map as a georeferenced image
• Property boundary as a shapefile
• Prior drainage design as a KML file

Each layer can be toggled independently for different planning views.

Reference layers are automatically included in project backups created via the Deliver tab.

What's Saved:

• Raster Images: Converted to PNG format and stored in the backup ZIP
• Georeferencing Data: Extent, transformation, opacity settings
• Vector Data: Exported as GeoJSON in WGS84 coordinates
• Layer Names: Original file names preserved

Restore Behavior:

When you restore a project backup:

1. All reference layers are automatically recreated
2. Georeferenced images are positioned exactly as they were
3. Vector layers are re-imported with original styling
4. Layers appear in the Map Layers control ready to toggle

• Source Quality Matters: High-resolution scans produce better georeferencing results than blurry photos
• Use Vector When Possible: If you have the choice between a scanned map and a KML/shapefile of the same data, use the vector format - it's more accurate
• Test Alignment: After georeferencing, draw a test line over a known feature and compare with satellite imagery to verify accuracy
• Document Limitations: When sharing designs that relied on reference layers for utility placement, include disclaimers about accuracy and need for professional locates
• Backup Regularly: Reference layers are included in project backups, so save backups after adding reference data
• Legal/Survey Data: For official boundary data, use certified survey files in shapefile format rather than georeferencing scanned documents

Learn how to use Geo-Surface Drain Pro through our comprehensive video tutorial library. Click any video below to watch.

1. Open or create a project so your work saves itself. See Your Projects Folder
2. Define your field: Project tab > Define Your Field > Upload field boundary or Draw field boundary. Include the way to the outlet if it lies outside the field. See Define Project Area
3. Get the elevation: Project tab > Get Elevation Data > Download elevation for this field, or use your own RTK survey under Other elevation sources. See Get Elevation Data
4. Create the analysis layers: Project tab > Create Analysis Layers > Create Drainage Layers. See Analysis Layers
5. Read the field before you draw: flow lines show the draws where mains belong; depressions, ponding and wetness show where the water stands. See Analysis Overlays

How to: Get started.

1. Set your limits first: Design tab > sliders button beside Active Design > Drainage settings > Tile design (depths, grade, spacing, pipe). See Design Parameters
2. Draw the main from the outlet up the draw: tool rail > Draw drain > Main. See Drawing Drain Routes
3. Fit its grade: Best-Fit under Grade design, and read the profile chart. See Grade Analysis & Best Fit
4. Add sub-mains and laterals: draw one lateral, then lay the bank with Copy offset to a break line, Mirror across the main or Herringbone laterals. Targeting depressions instead of a pattern? Add surface inlets. See Laying Out Laterals and Surface Inlets
5. Clear the violations: Active Design > Violations steps through every run with a red S, D or ✕. See Depth Violation Detection and Connection Validation
6. Check for gaps: Map Layers > Drainage coverage
7. Size the mains: Design tab > Sizing > Auto Size Mains. See Tile Sizing & Specifications
8. Optional: try a heavy rain with and without the tile in the Drainage Simulation (Beta)
9. Deliver: the report, machine files and a backup — see Finishing below

How to: Your first tile plan, Grades and sizing, A targeted tile plan with surface inlets, Drainage simulation.

1. Mark culverts under roads and lanes (Project tab > Mark Culverts) so the water routes the way it really does
2. Find the draws with Flow Lines and Drainage Basins, and the depressions the ditch must cross
3. Set the ditch limits: Drainage settings > Surface design. See Design Parameters
4. Draw the main ditch from the outlet up the draw: tool rail > Draw drain > Surface > Main Drain; then Tributary up the side draws
5. Fit the grade with Best-Fit and clear the violations, as for tile
6. Carve the ditches into the ground: Design tab > Surface > Surface with drains carved in, then create the drainage layers again to see what is left standing
7. Deliver — see Finishing below

How to: A surface drainage plan.

1. Check how much water stands: Map Layers > Ponding after rain
2. Switch workspace: top bar > Workspace > Landforming. The Design tab now holds Landforming Design
3. Set it up: Analyze field (recommend settings), then choose the Outlets where water may leave and place your Benchmarks
4. Solve design surface and read the cut, fill and depths under Details
5. Check that it drains: Use design as active surface, then create the drainage layers again
6. View 3D Before / After, then Generate PDF Report and Export design… for the machine

See Landforming. How to: Land forming: fill the lows and flats.

1. Report: Deliver tab > Professional Reports > Generate Report. See PDF Reports
2. Machine files: Deliver tab > Send the design to the machine > pick the equipment brand. See Exporting Your Designs
3. Backup to share: Deliver tab > Project Backup > Backup Project. Your client can open it in the free Geo-Surface Viewer. See Project Backup & Restore

How to: Deliver: reports, machine files and backups.

Where to find it: Map toolbar (bottom left of the map) > GPS (the crosshair)

Shows where you are on the map from the device's own location. Allow location when the browser asks. The button steps through three states:

1. First press – GPS on, north up: a red dot marks your position and the map centres on it at the first fix
2. Second press – Track up: the icon becomes an arrow, the map follows you and turns so your direction of travel is at the top. It turns only while you are moving, so it does not spin when you stand still. The compass button that appears on the map takes you back to north up (GPS stays on)
3. Third press – GPS off

Hold the mouse over the button to see which state it is in. Accuracy depends on the device: a laptop GPS receiver or a phone sharing its location gives usable positions; Wi-Fi positioning is rougher; an RTK receiver is far tighter.

Editing waits while GPS is on

While GPS is on (either state) the app is for looking, so a bump in the field cannot move a run. You can still select runs, read profiles, use layers and measure, and every export still works. Editing tools, Undo, the Design panel values, drainage settings, boundary edits and anything that replaces the ground are locked: the right-click menu and the tool finder show Turn GPS off to edit. Press the GPS button until it is off and editing comes back.

Where to find it: Map toolbar > GPS survey (the route icon, beside GPS)

Walk or drive a proposed route with a laptop and the app turns your track into a run, exactly as if you had drawn it. Only your position comes from GPS: the heights come from the elevation loaded for the field (LiDAR or your survey), never from GPS altitude, which is far too rough for drainage.

1. Click GPS survey and choose the system (Surface or Tile) and the run type in Select Drainage Type. GPS turns on by itself if it was off
2. A red button at the bottom of the map reads Acquiring GPS… for a few seconds while the position settles, then Stop Survey (Recording…), and counts the points as you go. A magenta line follows your track
3. Start at the outlet, as when drawing, so the run flows the right way. A lateral, sub-main or tributary must start on its parent: nothing is recorded until you are within 30 ft of a suitable main, and the button says so (Walk to within 30 ft of a tile main or sub-main to start). The first point is snapped onto the parent
4. Click the red Stop Survey button (or GPS survey again) at the end of the route. The track becomes a run with its name, its profile opens in the chart, and it can be undone like any new run. A track of fewer than two points is discarded

GPS stays on after the survey, so the app is still in view mode: press the GPS button until it is off before you edit the new run (Best Fit, sizing, trim and so on). A wobbly track can be cleaned up with Edit vertices, or redrawn using it as a guide.

Which device: the full app runs in desktop Chrome or Edge, so the survey is recorded on a laptop. To see your position on a finished design on a tablet or phone, open a project backup in the free Geo-Surface Viewer, which has the same GPS button; it does not record surveys.

Design parameters are the limits every run is graded to: depths, minimum grade, pipe and ditch shape. They live in two places:

• Drainage settings — the starting values. Every new run you draw takes them by its type (tile main, sub-main, lateral, surface main or tributary). See Drainage settings below.
• The run's own settings — select a run and the Active Design card shows its values. Change them there to give one run different limits. See One run's settings below.

A new run is graded with Best Fit as soon as you finish drawing it, so you never start with blank values.

Where to find it: Design tab > Active Design > the sliders button at the right of the heading. Or press Ctrl+K and type “drainage settings”.

Drainage settings holds the values every new run starts with. Its sections are listed on the left: Tile design, Surface design, Flow estimates and Currency (in Denmark and Finland also Data sources, for your own elevation-service key). Click one to jump to it. Find a setting above the list narrows the dialog to the fields whose name matches what you type, in every section. The (i) beside a field explains it, and the ? in the title bar opens this page.

Area-weighted soil suggestion

Once your field's soils have loaded (see Soil-Informed Starting Parameters), Tile design opens with an Area-weighted soil suggestion. Each soil has its own suggested drain depth, spacing, drainage coefficient and envelope. The row weights them by the share of the field each soil covers, counting only the soils that need drainage (poorly, very poorly and somewhat poorly drained), and names every soil it left out with the reason. For the target lateral depth, lateral spacing, project drainage coefficient and lateral perforation it shows the suggestion (with its range), your current value (Now) and where your value sits against the soils' ranges, for example below its range. In Canada the suggestion comes from the field's one modelled soil summary instead of soil-survey map units.

Use these sets the project drainage coefficient straight away (see below) and fills the other three fields with the suggestion. Those three are kept when you click Save defaults; close the dialog without saving and they stay as they were. The lateral perforation is filled when most of the soil area agrees: Sock Filter when most of it needs a sock, Regular Perforated when most of it needs no envelope. Until soils have loaded, the row says how to get them.

Project drainage coefficient

The project drainage coefficient is how much water, in inches a day (mm a day in metric), your tile must carry off the ground above it. There is one for the whole project. You see it in four places: the Project tab, beside the Region; the Tile Sizing card on the Design tab; Drainage settings > Tile design; and the Auto Size Mains panel. Change it in any of them and all of them change at once.

Auto Size sizes every main and sub-main to it, and a surface inlet on a lateral sizes that lateral to it. Every run you have sized, whether by Auto Size or by hand on the profile, is checked against it: a run whose pipe carries less turns red in the profile's pipe-size editor, shows in the run finder's Violations list, and is starred in the report. Lower it and runs that now carry enough clear straight away; raise it and runs that fall short are flagged straight away. The report prints the project drainage coefficient and, separately, the coefficient each main was sized at.

It is saved with the project. A project saved before it existed opens on the coefficient its mains were last sized at (otherwise 3/8 in/day).

Tile design

Depths are a small table: Laterals, Sub-mains and Mains, each with a Minimum, Target and Maximum. Until you change the Sub-mains column it shows the lateral depths and follows them, so sub-mains are laid like laterals; type in it and new sub-mains take their own depths. Runs already drawn keep theirs. Target is where Best Fit tries to lay the pipe. A stretch shallower than Minimum is marked with a red S, deeper than Maximum with a red D (see Depth Violations). Set Maximum to the depth your plow reaches.

Setting	Starting value	What it does
Depth, laterals: Minimum / Target / Maximum	24 / 30 / 60 in (2.0 / 2.5 / 5.0 ft)	Tile laterals
Depth, sub-mains: Minimum / Target / Maximum	The lateral depths, until you set them	Tile sub-mains, which often sit deeper than laterals. Change type between lateral and sub-main moves a run to the new type's depths when its own depths were never changed; depths you edited stay. One Undo puts it back
Depth, mains: Minimum / Target / Maximum	36 / 42 / 60 in (3.0 / 3.5 / 5.0 ft)	Tile mains. Mains sit deeper so laterals join near the top of the main
Lateral Spacing	50 ft	Centre-to-centre distance between laterals. The layout tools start from it; drained area, pipe sizing and the report use it
Min Grade	0.1%	Least fall toward the outlet (0.1% is 1 ft per 1,000 ft). Best Fit goes deeper rather than flatter
Max Bend per Vertex	45°, not enforced	Used only when Enforce Max Bend per Vertex while drawing & editing is ticked (see below)
Default Tile Specifications	Lateral 4", Regular Perforated; main Unassigned	The pipe each new run starts with. Lateral Size 3"–10"; Lateral Perforation Regular Perforated, Narrow Slot or Sock Filter; Main Size Unassigned or 4"–48"; Main Wall Type Unassigned, Single-Wall or Dual-Wall. A main left Unassigned gets its size from Auto Size. Outside the US and Canada the sizes are the ones sold in your country, in millimetres (see Pipe Sizes below), and any size you add is offered too
Pipe Sizes	3"–48" in the US and Canada (3, 4, 6, 8, 10, 12, 15, 18, 21, 24, 30, 36, 42, 48); the sizes sold in your country elsewhere	The one list of pipe sizes every size picker, Auto Size, the map colours and the report use. Add a size: type it (inches, or millimetres in a metric country) and click Add. A size already on the list is refused (21" is there already), as is one smaller than 2" (50 mm) or larger than 72"; the line under the box says why. In millimetres you can also give its inside diameter: the pipe's capacity is worked out from it (leave it blank to use the size itself). Each size you add has a map colour, a report price and Use in Auto Size (on unless you untick it; untick it and the size is still offered in every picker but Auto Size never chooses it). Remove works only while no run uses that size. The sizes you add are kept in this browser for every future project and saved with the project, so a project opened on another computer brings its sizes with it
Max drainage coefficient for sizing	Blank (optional)	Blank, Auto Size gives each main the smallest pipe that carries the coefficient you size with. Set, a pipe that would drain more than this is not recommended, and when no size fits between the two Auto Size asks you to choose (see Tile Sizing)
Outlet Transition Distance	25 ft	Outlets & Connections. The depth limits start to count only this far from the outlet, so a run can climb out of a deep outlet. 0 turns it off
Maximum Transition Grade	5%	Steepest the pipe may be inside the outlet transition
Connection Offset	4 in	How far above the main's invert a run joins when Force connection is on, so the tee is not cut at the bottom of the pipe (see Connection Validation)
Boundary Setback	10 ft	Layout Tools. How far inside the field boundary the layout tools (Herringbone, Copy offset, Mirror and Aligned lateral) stop new laterals
Minimum Lateral Length	20 ft	A lateral a layout tool would leave shorter than this (cut off by another run, by ground already drained or by the boundary) is not laid

Overburden Settings

Where a pipe must go deeper than its Maximum depth (deeper than the plow reaches), the soil above that depth has to be dug off first: that is overburden.

Setting	Starting value	What it does
Allowable overburden before a cut	0 in	A stretch whose extra depth is no more than this is not counted as a cut
Overburden Width	15 ft	Bottom width of the cut, for the volume
Overburden Side Slope (H:1)	Vertical	Vertical, or 1:1 to 6:1
Excavated start	25 ft	The first stretch of every lateral and sub-main, measured from where it joins its main, which you dig out anyway to set the plow in. A cut in that stretch is not counted; 0 counts the whole run

A cut that carries on past the Excavated start is counted from that point on, at the depth it has there. Mains are always counted in full. Overburden inside the Excavated start is left out of the map labels, the overburden files and the report. The setting is saved with the project; a project saved before it existed opens with 25 ft, so its overburden is counted with it.

Surface design

Setting	Starting value	What it does
Min Depth / Max Depth	0 / 12 in	How far below the ground the ditch bottom may sit. A new ditch also takes Min Depth as its Offset Depth
Min Grade	0.05%	Least fall toward the outlet
Ditch Bottom Width	8 ft	Used for the earthwork volume and cross-section
Side Slope (H:1)	6:1 (smooth)	Vertical, 1:1 (45°), 2:1, 3:1, 4:1, 5:1, 6:1 (smooth), 8:1 or 10:1 (grassed waterway). 6:1 rises 1 ft every 6 ft across, smooth enough to farm through. Sloped sides move more soil than vertical ones
Steepest ramp from a fixed start or connection	2% (0.1% to 20%)	How steeply the ditch bottom may climb from a fixed start depth or a forced connection that sits below the ordinary fit, until it meets the fit. Min Grade still applies when it is steeper. A change applies the next time a ditch is graded; opening a project never re-grades it

Flow estimates

A drainage coefficient is how many inches of water a day the drains carry off the area above them. Flow estimates holds three: Standard rate (0.5 in/day to start), High rate (0.75) and Heavy rate (1.00). With the flow lines on, pointing at one on the map shows the area that drains to that spot and its flow at each rate. Untick Show drainage-coefficient flow estimates on flow-line hover if you would rather not see them. These three rates are for flow estimates only. Tile is sized to the project drainage coefficient (see above), which is the one Use these fills from the soils.

Save defaults, Apply to existing, Reset

• Save defaults — every value shown applies to this project, every run you draw from now on starts with them, and the values you changed become your defaults for new projects on this computer. Runs already drawn are not changed. The button reads Saved! for a moment.
• Apply to existing — saves the defaults as above, then applies only the values you changed since the dialog opened to the existing runs of the matching type. It asks first, naming what changed and how many runs it reaches; runs whose depths or grade limits changed are re-graded to the new values. A changed pipe size replaces the size on every matching run except a size worked out from the flow (Auto Size, or a lateral sized for its surface inlet), which is kept and named. One Ctrl+Z puts every run back. A run that still breaks the new limits is named in a notice.
• Reset — puts every value back to the starting values in the tables above, after asking. This cannot be undone.

Where to find it: Design tab > Active Design, with a run selected (click it on the map, or pick it in the run list or Find a run)

Each run keeps its own settings, starting from Drainage settings. Change them here when one run needs different limits, for example a main that must stay shallow at a surface outlet, or a stretch under a road that needs more cover.

• Grade parameters: Min Grade (%), and Target Depth on a tile run or Offset Depth on a surface run. Max Bend appears too while Max Bend is enforced; blank means the default applies.
• Use fixed start depth (tile and surface mains): tick it and type a known outlet depth at station 0+00. See Grade Analysis.
• Force connection and Connection offset (runs joined to a parent and graded with Best Fit). See Connection Validation.
• Depth constraints: Min. and Max., and on tile runs Outlet transition, where Suggest works a length out from the maximum transition grade.
• Size and Form: the run's pipe (tile runs).

Apply changes

Typing a new value changes nothing yet. An Unapplied changes box appears at the foot of the Design panel, naming the run; click Apply changes and the run is graded again with the new values. One Undo reverses an Apply. Values that cannot work are refused with the reason and nothing on the run changes; unusual values ask first (see the checks at the top of this section).

Do I have to change the defaults before drawing?

No. The starting values work for a first plan. Setting the depths to your plow and the spacing to your soils first (the soil suggestion helps) saves changing many runs later.

I changed Drainage settings and my runs did not change.

That is expected: Save defaults only affects runs you draw from now on. Click Apply to existing to change the runs already drawn.

Apply to existing changed runs I did not mean to change.

Press Undo once and every run goes back. To change one run only, select it and change its own settings instead.

I typed a new value and nothing happened.

Click Apply changes in the Unapplied changes box at the foot of the Design panel. Values are not used until you do.

Can I see which runs have their own settings?

No. Select a run to see its values.

Where to find it: Design tab > Active Design > Grade design (select a run first). Open Profile Chart at the bottom right to see the result.

Grade design offers three ways to set the grade of the selected run:

• Best-Fit — the one to use almost everywhere. The app works the grade out for you.
• Guided — you pick where the grade changes; the app keeps the minimum grade.
• Freeform — the grade goes exactly where you click, with no rules enforced.

Clear (tooltip Clear grade) removes the run's grade; Export saves the run as a 3D line. Switching a graded run to another method asks first (Replace with Guided, for example), and Undo puts the old grade back.

Best Fit finds the grade that stays between the run's Min. and Max. depth, never drops below its Min Grade, and follows the ground as closely as those limits allow, near the Target Depth. Every new run gets it as soon as you finish drawing it, and Apply changes grades it again after you change the run's settings (see Design Parameters). Click Best-Fit to go back to it from a Guided or Freeform grade.

For tile, a target depth outside the min and max limits is moved to the nearer limit and the fit says so; the run's Target Depth is then set to the value used, so the panel, the report and the machine files agree.

Fixed start depth

When the outlet must be at a set depth (an existing tile, a ditch or a culvert), select the main, tick Use fixed start depth, type the depth and click Apply changes. It is offered on tile and surface mains and is off by default.

• Tile main: when the start is shallower than Min. depth, the main follows Min Grade until it has enough cover, then follows the ordinary fit.
• Surface main: the ditch bottom starts that far below ground and is raised upstream only where needed to keep rising at Min Grade. When the start is deeper than the ordinary fit, the bottom climbs no steeper than Steepest ramp from a fixed start or connection (2% unless you change it in Drainage settings) until it meets the fit.

Where the ground does not give enough fall, the start depth is kept and the shallow stations are marked as violations. The statistics show Fixed Starting Depth instead of Required Starting Depth.

Outlet transition

On tile runs, Outlet transition (under Depth constraints) is a stretch at the outlet end where the depth limits are relaxed so the pipe can rise or drop to meet the outlet, no steeper than the maximum transition grade; minimum grade still applies, and 0 turns it off. Suggest works a length out from the maximum transition grade. The chart shades the transition, and points there that pass a depth limit show as amber dots marked allowed, not as violations.

Use Guided when you want a few long, even grades a contractor can lay, at break points you choose.

1. Select the run and click Guided. The button turns orange and reads Finish Drawing.
2. Click the profile chart where the grade should change. Each anchor sits at the run's Target Depth under the ground there; the grade runs straight between anchors and on to the outlet, never flatter than Min Grade. A click near the far end snaps to the inlet. Alt-click an anchor to remove it.
3. Click Finish Drawing to run the checks. Esc cancels and puts the saved grade back.

Use Freeform when the grade must meet a fixed height: an existing tile, a culvert or a ditch bottom at a known depth. Nothing is snapped and nothing is enforced, so a flat or uphill grade is possible.

1. Select the run and click Freeform. The button turns orange and reads Finish Drawing.
2. Click the profile chart from the outlet up. A point lands exactly where you click. Drag a point to move it; Alt-click to remove it.
3. Watch the red S and D marks: they show where the grade is too shallow or too deep as you drag.
4. Click Finish Drawing to run the checks. Esc cancels.

Where to find it: select a run, then Profile Chart at the bottom right of the map. The outlet is at the left.

• Elevation Profile (blue): the ground along the run.
• Min Depth Line (green) and Max Depth Line (pink): the ground less the run's Min. and Max. depth.
• Best Fit Line or Grade Line (red): the designed pipe or ditch bottom.
• Depth Violations (red crosses): points outside the depth limits. See Depth Violations.
• Parent Connection (dot at the left end of a joined run) and Connections (dots on a main where its runs join). See Connection Validation.
• Overburden (orange shading): where a tile run is deeper than its Max. depth.
• Anchors and segment grades (Guided, Freeform), station labels, and dashed lines where a stepped main changes pipe size.

Hover anywhere on the chart to read the station, ground and grade elevations and the depth there, with a warning when the depth is outside the limits. Drag the handle at the top edge of the chart to make it taller or shorter.

Where to find it: Design tab > Surface > Surface with drains carved in > Burn drains into surface

Once your surface drains are graded, you can carve them into the elevation to see whether the plan drains the field before anyone digs.

1. Run Best Fit on every surface drain you want carved. The button stays grey, with "Draw surface drains and run Best Fit on each to enable.", until at least one has a grade; then the line under it counts them ("3 surface drain(s) ready to burn.")
2. Click Burn drains into surface. Each graded ditch is cut into the original elevation at its designed grade, and the result is saved as a new surface. Culverts you carved are kept in it.
3. The green line under the button says the new surface is ready, and the Active surface box at the top of the sidebar switches to it (for example Burned Elevation (drains + culverts)). The map colours, the elevation readouts, contours, exports and the drainage layers now read the carved ground.

Compare before and after

On the Project tab click Create Drainage Layers again and turn on Depressions (and Flow Lines) in Map Layers. The layers are now worked out on the carved ground: low spots the ditches drain disappear, and what is left shows where a short tributary, a surface inlet or some land forming would finish the job. To see the field as it is today again, set the Active surface box back to Raw Elevation.

Before you change the ditches again, set the Active surface back to Raw Elevation, so Best Fit reads the ground as it is and not the ditches you carved. To lay tile out so it drains to the ditches, design it with the carved surface active.

"Burn did nothing"

No ground was lowered, and the line under the button says why: the design grade sits at or above the ground everywhere (nothing to carve: run Best Fit again so the grade cuts into the ground), the drain is outside the elevation or runs over a hole in it (download elevation that covers it), or the design heights look about 3.3 times the ground (feet against metres: run Best Fit again on the same surface you are burning into). "No raw elevation surface to burn into" means no elevation is loaded yet.

What is Required Starting Depth?

After Best Fit, a tile run shows how deep its outlet end must be for the grade it found. On a lateral or sub-main, compare it with Connecting Depth, the main's depth where it joins (see Design Statistics).

What if Best Fit shows violations whatever I try?

Some ground cannot meet every limit along one run. Widen the run's Min./Max. depth, shorten or reroute it off the high ground, split it, or accept the deep stretch as overburden. See Fixing Depth Violations.

Do setting changes update the grade by themselves?

No. Click Apply changes after changing a run's settings; that grades it again.

Can I use Best Fit in the free viewer?

No. The viewer shows the grades saved in a project; working them out is part of the paid app.

Where to find it: Design tab > Active Design > the summary line under Grade design > More

Once the selected run has a grade, a one-line summary sits under Grade design: the run's name, length, average grade and depth range, then no violations in green or the number of violations in red (see Depth Violations). A sized main or sub-main whose size no longer fits the design also shows ↻ size out of date.

Click More to open the full Design Statistics for the run; Less folds them away again, and your choice is remembered. They update whenever the run's grade changes.

Run	Statistics
Tile main	Outlet Elevation, Required Starting Depth (or Fixed Starting Depth, or Starting Depth for a grade drawn without Best Fit), Target Depth, Average Depth, Min. Depth, Max. Depth, Average Grade, Run Length, and Overburden Length and Volume when there is overburden
Tile lateral or sub-main	Required Starting Depth, Connecting Depth, then Target Depth onward as for a main
Surface main	Outlet Depth, Average Depth, Min. Depth, Max. Depth, Average Grade, Run Length, Total Volume
Surface tributary	Connection Depth in place of Outlet Depth, then as for a surface main

Required Starting Depth

Tile runs graded with Best Fit: how deep the outlet end must be for the grade Best Fit found, rounded down to a whole inch. It is shown in bold as the main figure. With Use fixed start depth on, the row reads Fixed Starting Depth and shows the depth you set. A tile main graded with Guided or Freeform shows Starting Depth, the actual depth at its first point, instead.

Connecting Depth and Connection Depth

On a lateral or sub-main (Connecting Depth) or a surface tributary (Connection Depth): how deep the parent run is where this run joins it, rounded up to a whole inch. It is not this run's own depth. A lateral that joins near the top of its main has a Required Starting Depth at or shallower than this figure; the check is described in Connection Validation. When the run is tied above the main with a connection offset, the offset is noted beside it.

Outlet Depth

Surface mains: the ditch depth at the outlet (first point), rounded up to the next whole inch.

Outlet Elevation

Tile mains: the ground elevation at the outlet, for checking against survey points.

Target Depth

Tile runs: the run's own Target Depth setting, the depth Best Fit aims for.

Average, Min. and Max. Depth

Average Depth is weighted by distance along the run. Where a design runs above ground (a surface tributary crossing a low spot) that stretch counts as negative depth, and the report says how many feet are above ground. Min. Depth and Max. Depth are the shallowest and deepest points of this run's own grade (the parent's depth is not included). On a tile run with an outlet transition they are measured outside the transition, so they agree with the violation marks; the report and shapefile export give the range over the whole run. When a depth is past its limit or rounds onto it, extra decimals show the difference (for example 2.496 ft against a 2.5 ft minimum).

When the design uses the outlet transition to go past a limit, one more row, for example Outlet transition (first 25 ft), shows the deepest or shallowest depth there, marked allowed. That is a design setting, not a violation.

Average Grade

Total fall divided by run length, in percent. Example: 1.25 ft of fall over 500 ft is 0.25%.

Run Length

The length along the run as drawn, through every bend, measured on the WGS84 ellipsoid: the same ground distance a GPS receiver or a UTM coordinate system gives. Every length, station, spacing and area in the app, the report and the export files is measured this way.

Total Volume (surface runs)

Soil to move, in cubic yards, from the ditch's depth along the run with the Ditch Bottom Width and Side Slope in Drainage settings. Change either and the volume follows. Sloped sides move more soil than vertical ones.

Overburden Length and Volume (tile runs)

Shown in orange when part of the run is deeper than its Max. depth: the length of those stretches and the volume to dig off first, using the overburden width and side slope in Drainage settings. The first stretch of a lateral or sub-main (the Excavated start) is not counted. See Design Parameters.

Why is there no summary line?

The run has no grade yet. Click Best-Fit (or draw a Guided or Freeform grade).

Why is Connecting Depth deeper than my target?

It is the main's depth where the lateral joins, which the lateral does not control. A deep main there is normal; it leaves room for the lateral to join near its top.

Do the depths include the pipe or bedding?

No. Tile depths are to the designed grade line. Surface volumes use the ditch shape from Drainage settings.

Can I get the statistics for every run at once?

Yes, in the PDF report (Deliver tab). See Reports.

A depth violation is a point where a run's grade is shallower than its Min. depth (too shallow) or deeper than its Max. depth (too deep), for example a lateral 18 in deep where its minimum is 24 in. The app checks every run each time its grade changes (Best Fit, Guided, Freeform, Apply changes, an edit to the run) and when a project opens. You do not need to start the check yourself.

Inside a tile run's outlet transition the depth limits do not count, so points there are not violations (see Grade Analysis).

Where to find it: on the map; Design tab > Active Design > Violations under Find a run, and the summary line under Grade design; the profile chart

On the map: red S and D

A red S marks a stretch that is too shallow, a red D a stretch that is too deep. Each stretch gets one letter at its worst point, so the number of letters on a run is the number of separate problem areas. A shallow stretch also carries small s marks along its length at working zoom; a deep stretch keeps one D, and its orange overburden dashes (with an OB label giving the extra depth) show its length. The run's name gets a warning sign ⚠. Zoomed out to the whole field, each run thins to one letter at its worst point. Any other kind of violation shows a red ✕. The marks stay on every run, not only the selected one, and hovering a run lists every violation on it.

In the Design tab: the Violations count

• Violations under Find a run counts the runs with a depth, grade or connection problem. Click it to list only those runs; the arrows beside the warning sign step from one to the next.
• The summary line under Grade design describes the selected run: its red count is the number of points along it that break a limit; no violations in green means the run is clean.
• In the run list a run with depth problems shows in orange (see Connection Validation for all the colours).

On the profile chart: red crosses

The selected run's profile marks every point outside its limits with a red cross on the grade line, and the chart's header shows a red Violations tag. Hover the chart to read the depth at any point against the limits.

Select the run, change its settings in Active Design and click Apply changes; the run is graded again and the marks update. In order from simplest:

1. Give the run room. Lower its Min. depth for an S, or raise its Max. depth for a D (if your plow can go deeper). Often the limits were narrower than the ground allows.
2. Move its Target Depth when the whole run sits too deep or too shallow.
3. Check the minimum grade. A lower Min Grade lets a long run fall less, which helps a D at its outlet end. Do not go below what your drains need to run (0.1% is the usual tile minimum, 0.05% for surface).
4. Shorten or reroute the run off the high ground, or split it where the ground breaks.
5. Accept a deep stretch as overburden (dug off before the plow), when the extra depth is short and small.

Before you deliver, click Violations and work down the list until it reads 0.

Do depth violations stop me exporting?

No. They are warnings. You can save, export and print a report with violations present.

I see S and D on the map but not on the chart.

The chart shows the selected run only. Click the marked run (or use the Violations arrows) to see its profile.

Can I remove a mark by hand?

No. Fix the run and the mark goes.

My lateral is too deep near its main.

Common on steep ground: it must keep its minimum grade all the way down to the main. Raise its Max. depth or shorten it. On tile runs the Outlet transition lets the first stretch past the main go beyond the depth limits; check it is not 0 (see Grade Analysis).

Do violations change pipe sizes or flows?

No. Sizing and flows use the designed grade as it is.

• While you draw: a lateral, sub-main or tributary must start on the run it drains into. Draw > Lateral only takes a first click within 30 ft of a tile main or sub-main, then snaps onto it. This is a check on the map only.
• After grading (connection validation): once both runs have a grade, the app compares their designed heights where they meet. A joined run should enter the upper part of its parent, never below it.

A run can pass the first check and fail the second, when its grade puts its outlet below the parent's pipe.

At the station where a run joins its parent, the app takes the parent's designed invert and the joined run's designed outlet height:

• Pass: the run's outlet is at, above, or no more than 1 inch below the parent. The 1-inch tolerance absorbs small differences in the elevation data.
• Fail: the outlet is more than 1 inch below the parent, so water would have to climb into it.

The check runs over the whole network whenever a grade changes, a run is edited or deleted, or a project opens. Deepen a main so its laterals fit and they turn green as soon as you apply it, with nothing to reselect.

The connection dot on the profile

Where to find it: select the joined run > Profile Chart > the dot at the left end (Parent Connection)

A joined run's profile marks the tie-in with a dot at station 0, drawn at the parent's designed invert, once the parent has a grade. Black means the run comes in at or above the parent's pipe; red means its outlet sits more than 1 inch below it. Hover the dot to read the parent's name, the station where the two meet, the parent's invert and the difference. A run with Force connection sits above the dot by its connection offset. On the parent's own profile its joined runs show as Connections dots, green when they pass and red when they fail.

Where to find it: Design tab > Active Design (a joined run selected) > Force connection

Force connection makes Best Fit start the joined run on its parent's designed invert, so the two always meet. New laterals, sub-mains and surface tributaries start with it ticked. It is offered on runs graded with Best Fit; a Guided or Freeform grade keeps the heights you drew.

• Tile runs: the outlet is set to the parent's invert raised by the run's Connection offset (4 in unless you change it), so the tee is not cut at the bottom of the main. The default is in Drainage settings > Tile design > Outlets & Connections; each run can have its own in the field under the tick box. 0 ties the two inverts level. Projects saved before the offset existed reopen with 0, so nothing moves.
• Surface tributaries: the ditch bottom starts on the receiving ditch's bottom (a ditch has no tee, so there is no offset). Upstream it keeps the ordinary fit, raised only where needed so it keeps rising at Min Grade. Where the tie is deeper than the fit, the bottom climbs no steeper than Steepest ramp from a fixed start or connection until it meets the fit.

Where the ground does not allow it, the tie is kept and the shallow stations are marked as violations rather than the offset being quietly reduced. Lower that run's offset and apply again. An offset larger than the parent pipe would put the tee above the crown of the main; the app warns and still calculates it.

Each run's status shows as a colour in the run list and as a sign after its name on the map:

Run list colour	Map sign	Meaning
Green	✓	All checks pass
Orange	⚠	Depth or grade violations; connections are fine
Purple	✗	Connection problem only
Red	✗✗	Both
Black	(none)	No grade yet, so nothing to check

Runs that others join (mains and sub-mains) are bold in the run list. A main is flagged when one of the runs joined to it fails, so select each of its runs to find which one. A run with nothing joined to it and nothing to join gets no map sign. The Violations count under Find a run includes connection problems (see Depth Violations).

1. Tick Force connection on the joined run and click Apply changes. This is the usual fix.
2. Lower the main at that point: deepen the main's Target Depth or Min. depth and apply, so the run can join above it.
3. Raise the run: lower its Min. depth, or shorten it so it does not need to fall as far.
4. Move the junction to a point on the main where the main is deeper.

My lateral starts on the main but shows purple.

It passed the drawing check but its grade puts its outlet below the main. Tick Force connection, or see the fixes above.

Why did a run's colour change when I edited another run?

The check covers the whole network. Changing a main's depth changes every connection along it.

Must every run be green before I export?

No. Status colours are warnings. A run that is not joined to any main at all is different: it stops Auto Size, the PDF report and the machine exports until it is reconnected or deleted (see Tile Sizing).

Where to find it: Design tab > Sizing > Tile Sizing card > Auto Size Mains

Prefer a guided walk-through with pictures? See How to: Grades and sizing.

Sizing does two jobs:

• Auto Size Mains works out the pipe for every tile main and sub-main from the ground each one drains, your drainage coefficient and its grade, and can step a long main down in size toward its upper end.
• Size, Form and Perf in the Active Design card set the pipe of the selected run by hand: laterals, and any main you choose to size yourself.

Size the mains once the layout and grades are finished: a later change to the layout marks the sizes out of date (below). Auto Size is part of the paid app and the demo; the free viewer shows it locked.

Where to find it: Design tab > Sizing > Tile Sizing > Auto Size Mains

Auto Size works out the pipe for every tile main and sub-main in the design, one at a time, and shows you each one before anything is saved.

How it works

1. Click Auto Size Mains in the Tile Sizing card. The Tile Main Auto-Sizing Parameters panel opens.
2. Set the parameters:
   • Project drainage coefficient: the depth of water the system takes off the drained ground in 24 hours. The panel opens on the project's value (3/8 in/day in a new project unless you change it). Choosing another here changes it for the whole project, and the panel says so. See Design Parameters and Drainage Coefficient Guidelines below.
   • Max drainage coefficient (optional): leave it blank and every main gets the smallest pipe that meets the coefficient above. Type a maximum and a pipe that would drain more than that is not recommended — see Maximum Drainage Coefficient below. The same setting sits in Drainage settings and is saved with the project
   • There is no drain spacing to type — each run's drained width is read from your own layout (see Contributing Area Calculation below)
3. Tick Enable stepped main sizing to let long mains step down in size toward their upper end (see Stepped Main Sizing below).
4. Click Start Sizing. Each main and sub-main is shown in turn, the furthest upstream first:
   • without stepped sizing: its contributing area, Sized by (the stretch that decided the size, with its stations and grade, for example "Sized by 0+00 – 5+57 at 0.100%"), and 2–3 size buttons, each with the drainage coefficient that pipe actually delivers
   • with stepped sizing: the review table of its stretches (below), with Apply All
5. Pick a size (or Apply All), or click Skip to leave that run as it is. Cancel stops; sizes already applied stay.

When Auto Size will not start

Every lateral and sub-main must end on the run it drains into. A project saved by an older version, or a design brought in from another program, can hold a run that does not. Such a project opens with a red list, runs not connected to a main, at the top right of the map, and until the list is empty, Auto Size, the PDF report and the machine exports will not run. Click Auto Size Mains and a notice names them, for example Auto Size cannot run while 1 run is not connected to a main: T1-L5. Reconnect or delete it in the list, then try again.

• Reconnect beside a run opens the Reconnect tool on it: click the main or sub-main it belongs to, then Reconnect in the panel. It is one Undo step, and the run takes that main's next free name.
• Delete removes the run, with anything connected to it.

When the list turns green with Every run is connected, try again.

A main is judged stretch by stretch, never on its average grade. Geo-Surface splits the main wherever its grade line changes slope, so each stretch has one grade. For each stretch it works out the water arriving at its downstream end — every acre drained at or above it, at your drainage coefficient, plus every surface inlet at or above it (an inlet on a lateral or a sub-main counts from the point where that run joins the main) — and finds the smallest pipe that carries it at that stretch's own grade.

A single-size main gets the largest of those pipes, so no stretch is overloaded. The review names the stretch that set the size. A main that is nearly flat at its outlet and steep upstream can therefore need a much bigger pipe than its average grade suggests: a main at 0.10% for its first 557 ft and steep above it is sized for 0.10%. When you see a large single size, that is the reason — stepped sizing (below) can use smaller pipe on the steeper stretches.

Delivered Drainage Coefficient

Pipe comes in steps, so the pipe you install drains more than the target. For each option the review shows the coefficient that pipe actually delivers at the stretch that sized it: (what the pipe carries there, less the surface-inlet water entering there) ÷ the acres draining there. For example: 10" → 0.230 in/day (below target) · 12" → 0.380 in/day (meets target) ← recommended. On a main carrying large surface inlets the smaller pipe can show 0.000 in/day — the inlets alone would fill it.

Maximum Drainage Coefficient

Blank (the default) keeps the rule above: round up to the first size that meets the target. When you set a maximum, a size is recommended only if what it delivers stays at or below the maximum. If no standard size lies between your target and your maximum, the wizard stops and asks you to choose: the size under the maximum (short of the target, with what it delivers) or the size over the maximum (with what it delivers). Nothing is applied until you pick one. A main you size under the target this way is marked in the PDF report.

Upstream first. The wizard sizes every sub-main before the main it drains into, the deepest first, and the main last. A sub-main you make perforated in a pass is counted in its main's area in that same pass, so running Auto Size twice with the same choices gives the same sizes. A sub-main you skip is counted with the perforation it already has (non-perforated if it was never sized), and the main's review names it.

Undo. Each size you apply is its own undo step. One Undo right after an Apply takes back that size only; your drawing is untouched. Redo puts the size back. When you size only some of the runs (below), the whole pass is one undo step: one Undo puts every run in it back as it was.

Out-of-date sizes. A size from Auto Size fits the design as it was when you sized it. When the design changes under it — a lateral drawn, deleted, extended, moved or reconnected, a surface inlet placed, edited or deleted — the size is marked out of date. Splitting a lateral is not a change: the two pieces drain the same ground. The marks show:

• its map label carries a circular arrow, ↻, and hovering it says what it was sized for and what the design drains now (for example Pipe sized for 2.06 ac; the drawn design drains 3.81 ac)
• the run picker shows it after the pipe size (T1 (Main) - 10" SW NP ↻ size out of date), the run's summary line under Grade design shows size out of date, and its Design Statistics carry the same sentence as the hover
• Out of date under Find a run in the Active Design card counts these runs; click it to list only them
• the Tile Sizing card says how many runs need re-sizing and names them, for example ↻ 1 run needs re-sizing: T5
• when a surface inlet is what changed, the sentence names its flow (for example Pipe sized for 35.37 ac (no surface-inlet flow); the drawn design drains 39.61 ac (including 30 GPM of surface-inlet flow))
• the Auto Size panel lists every out-of-date run before you start, and a run's review says its current size is out of date
• the PDF report prints the same sentence under the main
• shapefile, DXF, KML, Ditch Assist and machine exports list the out-of-date runs first; choose Export anyway or cancel

To clear it, finish the layout, then click Auto Size Mains again: the panel lists every out-of-date run with both figures before you start. When some of your sized runs are out of date and the rest are not, the panel offers two choices:

• Size only the runs that need it (the default), with how many and which, for example Size only the runs that need it (1): T2. Only those runs are shown, along with any main or sub-main never sized; every other run keeps its pipe exactly as it is
• Size every main: every main and sub-main is shown in turn, as before

Click Start Sizing and apply the new size. The arrow goes and Out of date drops to 0.

Size one run. To re-size a single main or sub-main without opening the panel:

• right-click it on the map and choose Auto Size this run, or
• select it and click Re-size this run at the top of its profile, beside Edit pipe sizes, or
• click the ↻ line in the Tile Sizing card to size exactly the runs it names

Each opens the same review for those runs only, at the project drainage coefficient, and leaves every other run as it is. A run sized as stepped is sized stepped again. A run whose pipe sizes you set by hand on the profile still asks whether to keep them or rebuild them. When sizing a sub-main changes the load on the main it drains into, the pass asks at the end, for example T1 also needs re-sizing - size it now?; choose Size it now to size it in the same pass, or Not now to leave it marked out of date.

Nothing is re-sized on its own. An edit that clears a run's Auto Size sizing (extending, trimming or reshaping it) takes its size off the run picker at once; the run shows unsized until you size it again. A main sized in a version before 3.2 is not marked when you open the project, since its acres were worked out under the earlier rule; the capacity check in the report and the hover still says whether its pipe carries the design. Size it again once, and it is followed from then on.

The project drainage coefficient is the field's target: Auto Size sizes the mains and sub-mains for it and checks them stretch by stretch. A tile lateral is shown for information only. Hover a lateral to see its design flow (its drained strip at the project drainage coefficient plus any surface inlet on it, in GPM and cfs, or L/s in metric) and its Max DC: the most its own pipe can drain over its strip, at the stretch that limits it, in in/day (mm/day in metric). For example Max DC 0.82 in/day.

A Max DC above your target is normal on shorter and steeper laterals. One below it is shown the same way: a 4" single-wall lateral at 60 ft spacing and 0.05% grade delivers about 1/2 in/day at 1,275 ft, and less the longer it runs. Auto Size, the map and the PDF report do not flag laterals. The design shapefile carries each lateral's flow, capacity used and Max DC. A surface inlet placed on a lateral still sizes that lateral for the inlet.

Mains and sub-mains show the same figure, where it matters most. Hover a sized main to see its design flow at the outlet and its Max DC: the drainage coefficient it actually delivers, which is the lowest along the run, at its bottleneck. It stands beside the project drainage coefficient, and the one the main was sized at when that differs, for example Max DC 0.77 in/day (target 0.50 in/day; sized at 0.75 in/day), and turns red when it is below the target. Until a main has been sized it shows no Max DC: its pipe, wall type and perforation are not settled yet, and each changes the figure. The PDF report keeps the full working: the limiting stretch, its flow and capacity, and % used.

Stepped main sizing calculates variable pipe sizes along a single main line, using larger pipe at the outlet (where all flow accumulates) and progressively smaller pipe toward the inlet (where less area drains). This can reduce material costs compared to using a single size for the entire main.

Stepped sizing requires a grade line covering the entire main; complete the grade before sizing a partly graded run.

Each reduction sits at the first connection above which the smaller pipe carries all the water still to come, at every stretch's own grade, then rounds toward the inlet to the next 20 ft pipe length. The larger pipe never stops short of a connection that needs it, and the resulting reaches are checked again for capacity. A lateral that joins exactly where the size changes is counted on the larger pipe below it.

A flat stretch is sized for the water that actually reaches it. A flat stretch near the upper end of a main, where only a few laterals are left, no longer pushes a larger pipe down the whole main. Past the last connection the main keeps the size below it.

A flat or adverse grade stops sizing for that main and names the affected stations; correct that stretch before sizing again.

Stepped sizing, single-size sizing, the PDF report and the flow figures you see when you hover a main all use the same calculation, so a pipe the wizard picks is never reported as undersized for the flow it was picked for.

How It Works:

When enabled, the system divides the main into stretches at every lateral connection and every change of grade. Each stretch is sized for the water entering above its downstream end (every lateral, sub-main and surface inlet above it) at its own grade. A pipe is never smaller than a pipe above it, so each size runs down to the stretch that needs it and steps down where the next size carries the rest.

The contributing area shown against a segment is the load at that segment's downstream end — the point in the segment carrying the most water, and therefore the flow the segment has to be sized for. In version 3.0.x the figure was taken from the upstream end, which understated it; on a carried-over project you may see a larger acreage for the same run, and a perforated segment can move up one pipe size as a result.

The review table

1. Click Auto Size Mains, tick Enable stepped main sizing, check the Project drainage coefficient and click Start Sizing.
2. For each main a Stepped Sizing review opens, one row per stretch:
   • Station from Outlet: where the stretch starts and ends, measured along the main from its outlet (6+00 = 600 ft)
   • Size, Wall (SW single wall, DW dual wall, smooth inside) and Perforation (NP non-perforated, for a main that only carries water) — each one a list you can change
   • Cum. ac: the acres the stretch carries
   Under it, Drained width per run lists each run with its station, side, length and the width it was credited.
3. Change any row if you need to, then click Apply All (Skip leaves this main as it was).

Change one stretch of a sized main: run Auto Size Mains again with stepped sizing, Skip every main you want left as it is, and in that main's review change the row's Size or Wall. A size below what a stretch needs is marked (< req) and shaded red. Click Apply All; one Undo takes it back. Picking a size in the Active Design card instead replaces all the steps with one size.

In metric the table shows stations in metres the way the report prints them (0+000) and the area column in hectares.

Above the review table, Rebuild main using: Single wall / Dual wall / Dual wall only where it drops a size builds a new schedule for the selected wall. The third choice uses dual wall only on the stretches where it needs a smaller pipe than single wall, and single wall everywhere else. The choice starts from Main Wall Type in Drainage settings (Tile design), or Single wall when it is Unassigned. Dual wall can move a step closer to the outlet, shortening the larger pipe. Perforation choices stay at their exact stations, even when the new size steps cross them. The schedule is saved only when you click Apply All; a failed rebuild keeps the previous review.

Lowest material cost. Once you have entered pipe prices (a price for each pipe type, under Tile Pricing in the report options), each of the three choices shows what its pipe material would cost, and the review opens on the cheapest. A choice that uses a pipe with no price entered says which one and is not compared; the review then opens on your main wall type as usual. Without prices, nothing changes.

Rebuilding resets manual diameter and per-row wall overrides; perforation choices are kept.

Running Auto Size again keeps perforation. When a main already has a saved schedule, each new segment starts with the perforation of the saved segment at its middle, so a segment you made perforated stays perforated after you add a lateral and size again. A run with no saved schedule starts with the perforation in its pipe specification: a lateral changed to a sub-main was laid out as perforated pipe, so its segments start perforated. A carried perforation is marked in the row () and sizes the pipe exactly as choosing it yourself would; change it in the row if the pipe will be solid.

Editing a sized run keeps its perforation. Extending, trimming, moving, splitting or reshaping a main clears its Auto Size sizing, so it draws unsized until you run Auto Size again, but the perforation you chose is kept. The next Auto Size starts those stretches perforated again, marked in the row as kept from before the edit; a stretch that ran to the end of the main still runs to the new end after an extension. Choosing a size yourself replaces it.

Changing one row leaves the other size changes where they are. A size change that no longer changes the pipe is dropped.

Segment Visualization:

After applying stepped sizing, the elevation profile chart displays:

• Dashed vertical lines at each segment boundary (where pipe size changes)
• Size labels on each segment (e.g., "12\" SW", "8\" SW")
• The visualization updates when you switch between lines

In PDF Reports:

Stepped sizing data appears in the Main Lines Analysis section as a breakdown table showing each segment's station range, length, pipe size, wall type, perforation, and area drained. The profile chart in the report also shows the segment boundaries.

For each main or sub-main, the app works out the contributing area from the runs you have actually drawn. Each run is credited the width of ground it really drains — the width the runs lying beside it leave it — rather than one spacing applied to the whole field.

How a Run's Drained Width Is Decided

• Along each stretch of a run, its neighbour on each side is the nearest lateral or sub-main lying beside that stretch on the ground: measured square to the run and within 100 ft. It can hang on the same main or on another one. Anything within 100 ft is taken as a bank: a bank drawn 100 ft apart drains 50 ft each side; a gap wider than 100 ft is an open side
• Along that stretch it is credited half the distance to that neighbour on each side; its width is the average over its whole length
• Where nothing lies beside a stretch — the end of a bank, a bank facing a gap, a single run on its own, or the part of a long lateral that runs on past a shorter one — that stretch is credited 25 ft on that side
• So the ground between two runs is counted once, split half-way between them, and drawing another lateral never lowers the drained area: a lateral drawn beside part of another only moves the boundary between their strips along that part
• A run further along the main is not a neighbour just because it is on the same side: on a main that bends, a lateral on the far leg is nowhere near a lateral on this leg, and neither is the first lateral of the next bank beyond a gap
• Area (acres) = the sum of (each run's length × its own width) ÷ 43,560

A bank at 40 ft: every run in the middle is credited 40 ft, and the run at each end 20 ft on the inside plus 25 ft on the open side, so 45 ft. Half a bank at 20 ft and half at 40 ft: the close runs are credited 20, the wide runs 40, and the run standing between the two spacings 30 — 10 ft on its close side and 20 ft on its wide side. A single lateral into a wet spot is credited 25 ft either side, 50 ft in all — even when other laterals hang on the same side of the main further along. Two banks with a gap between them: the lateral at each end facing the gap is credited 25 ft on that side, not half the gap. A bank at an angle to the main is credited the spacing measured square to its laterals, not the longer distance between them along the main.

Split laterals: splitting a lateral turns its lower half into a sub-main carrying the upper half. The two halves are still one lateral for drained width: both are credited the width the lateral had among its neighbours, so a split never changes a main's acres. Draw more laterals on the new sub-main and it is treated as a real sub-main.

Sub-mains: a sub-main with laterals of its own is credited no width on the main — its laterals already drain the ground beside it, and they are sized among themselves on the sub-main. It still stops its neighbours on the main: a lateral beside it is credited half the gap to the sub-main, not half the gap to the next lateral beyond it. A sub-main with nothing connected to it is credited exactly like a lateral. No piece of ground is ever counted twice.

Perforated Mains (if selected)

• A perforated main also drains 25 ft on each of its two sides — but only along the stretches of its length that no run covers
• Where laterals hang, their strips already reach the main, so the main adds nothing there. A side with no laterals at all is credited along its whole length
• So a main with laterals on one side only picks up its own strip down the bare side, and a main with laterals on the first half picks up its own strip on the second half
• A stepped sub-main perforated on only some of its segments adds its own strip to its main only along those segments

The review popup for each main lists every run with its length and the width it was credited, and states, for each side of the main, how much of its length no run covers, so the acreage can always be read back to the layout that produced it.

Without stepped sizing, each main and sub-main gets 2–3 size buttons, one per kind of pipe:

1. SW Non-Perf (green)

• Always shown
• Uses only lateral contributing area (no main drainage)
• Standard corrugated single-wall pipe
• Best for collection mains that don't directly drain soil

2. SW Perforated (blue-green)

• Only shown if calculated size ≤ 15 inches
• Includes main's own drainage contribution in area calculation
• After clicking, shows perforation type picker:
  • Regular Perforated: Standard perforations
  • Narrow Slot: Narrow slot openings (fine soils)
  • Sock Filter: Fabric sock wrapped pipe
• Best when main also needs to drain soil along its length
• When the run already has a perforation (from its pipe specification, its last sizing, or kept from before an edit), the review says so, for example Kept from its pipe specification: Sock Filter over its whole length. Choose SW Perforated to keep it; the other sizes are solid pipe., and the picker marks that type Kept from this run. The choice is still yours

3. Dual-Wall (grey)

• Always shown
• Smooth interior wall, corrugated exterior
• Always non-perforated (dual-wall mains don't come perforated)
• Higher flow capacity due to smoother surface (lower roughness coefficient)
• Best for high-flow collection mains or challenging grades

The sizing algorithm uses Manning's equation with size-dependent roughness coefficients:

Flow Rate (Q):

Q (cu ft/sec) = Area (acres) × Drainage Coefficient (in/day) × Conversion Factor

Conversion Factor = 43,560 ÷ 12 ÷ 3,600 ÷ 24 = 0.042014

Example: 5.74 acres × 0.375 in/day × 0.042014 = 0.090 cu ft/sec

Manning's Equation Roughness Coefficients:

The system uses piecewise roughness values based on pipe size range:

Single-Wall Pipe:

• ≤8 inches: n = 0.015 (smoother for small pipes)
• 8-12 inches: n = 0.017 (moderate roughness)
• >12 inches: n = 0.020 (higher roughness for large pipes)

Dual-Wall Pipe:

• All sizes: n = 0.012 (smooth interior wall, consistent across sizes)

Pipe sizes outside the US and Canada

Outside North America the size pickers list the drain pipe sold in your country, by the size printed on it: 110 mm, 160 mm. In most of Europe, the UK, Australia and New Zealand that number is the pipe's outside diameter; the bore is 10–17 % smaller, so a 60 mm UK pipe has a 50 mm bore. In Denmark, Norway and Estonia the number is the inside diameter. Capacity is always worked out from the inside diameter of the pipe, with the same formula and the same roughness steps as above, taken at the bore (8" = 203 mm, 12" = 305 mm). Auto Size picks the smallest size on the list whose bore carries the flow. Hover over a size in a picker to see its inside diameter. A size marked typical comes from limited published figures: check the bore with your supplier, or add the pipe you buy with its own inside diameter in Drainage settings → Pipe Sizes.

Pipe capacity is Manning's full-pipe flow: Q = (1.486 ÷ n) × A × R^2/3 × S^1/2, with the pipe's area A and hydraulic radius R (a quarter of its diameter) and the stretch's own grade S. The smallest standard pipe whose capacity carries the flow is chosen. A pipe is never counted as carrying more by running under pressure.

Calculated sizes are rounded to the sizes on your size list: in the US and Canada 3", 4", 6", 8", 10", 12", 15", 18", 21", 24", 30", 36", 42", 48"; elsewhere the sizes sold in your country (see Pipe sizes outside the US and Canada above); plus any size you added in Drainage settings > Pipe Sizes with Use in Auto Size on.

The Rule — Always Round Up:

• Geo-Surface picks the smallest standard pipe whose diameter is at least the calculated hydraulic diameter.
• A calculated size is never rounded down, no matter how close it sits to the size below — rounding down would knowingly install less capacity than your drainage coefficient calls for.

Minimum Size:

• Mains and sub-mains: Minimum 4 inches (system enforces this regardless of calculation)
• Laterals sized by the surface-inlet tool or the capacity check: minimum 4 inches, from the same size list and roughness table

Maximum Size:

• If the flow needs a pipe larger than the largest size on your size list (48 inches in the US and Canada; in other regions the largest size sold there), the review shows one sentence naming that size instead of a size button (older versions showed "BIG!")
• Add a larger size in Drainage settings > Pipe Sizes and run Auto Size again, or split the area between more mains

Examples:

• Calculated 4.08" → 6" (4" is smaller than the calculation requires)
• Calculated 6.4" → 8"
• Calculated 8.4" → 10"
• Calculated 11.5" → 12"

Where to find it: Design tab > Active Design > select a run > Size, Form (and Perf for a main) > Apply changes

Use these for laterals, and for any main or sub-main you want to size yourself.

• A lateral: Size 3", 4", 6", 8" or 10"; Form Regular Perforated, Narrow Slot or Sock Filter. New laterals start on the lateral size and perforation in Drainage settings (Tile design), 4" Regular Perforated unless you changed it.
• A main or sub-main: Size Unassigned or 4" to 48"; Form Unassigned, Single-Wall or Dual-Wall; Perf Non-Perforated, Regular Perforated, Narrow Slot or Sock Filter.

As soon as you change one, the Unapplied changes box appears at the foot of the panel; nothing changes on the run until you click Apply changes, and one Undo takes it back.

Where to find it: Design tab > select a tile main, sub-main or lateral > profile chart > Edit pipe sizes (top right of the chart)

Change where a run steps down from one pipe to the next, add or remove steps, and pick each stretch's pipe, right on the profile. It works on any tile run, including a lateral you want to step up near its outlet.

• Each pipe stretch shows as a coloured band along the pipe line with a label above it: size, wall, perforation and stations (for example 8" SW NP · 6+00–10+84), and under that the land draining into it and the drainage coefficient that pipe delivers (21.4 ac · 0.42 in/day).
• Change a stretch: click its label and pick the size, wall and perforation.
• Move a step: drag the marker between two stretches. It moves in 20 ft pipe lengths from the outlet and stops a pipe length short of the next step or the end of the run.
• Add a step: click on the pipe line. Both halves keep the same pipe until you change one.
• Remove a step: click the × on its marker. The two stretches become one with the larger of the two pipes, so removing a step never makes the pipe smaller.

A stretch whose pipe delivers less than the project drainage coefficient turns red and shows how far short it is, and the line under the chart lists it. You can still apply it: the run then shows in the run finder's Violations list until you change it.

Nothing changes on the run until you click Apply, and one Undo takes it back. Cancel, turning the mode off or choosing another run drops your changes (it asks first if you made any). The map colours, the report's pipe schedule (with each stretch's delivered drainage coefficient), the materials list and the exports all follow what you applied.

The run picker at the top of the Active Design card shows each run's pipe after its name:

• T1-L1 (Lateral) - 4" Regular — 4" regular perforated (Narrow = narrow slot, Sock = sock filter)
• T1 (Main) - 8" SW NP — 8" single wall, non-perforated; a stepped main shows its size at the outlet
• T1 (Main) - 12" SW Regular — 12" single wall, regular perforated
• T1 (Main) - 15" DW NP — 15" dual wall
• T1 (Main) - Unassigned — not sized yet

SW = single wall, DW = dual wall, NP = non-perforated. A size that no longer fits the design ends with ↻ size out of date.

The drainage coefficient represents the rate of water removal needed from the soil, measured in inches of water per 24-hour period.

Typical Values by Crop:

• Row Crops (Corn, Soybeans): 3/8" - 1/2" per 24 hours
• Small Grains: 1/4" - 3/8" per 24 hours
• Pasture/Hay: 1/8" - 1/4" per 24 hours

Where to find it: Project tab > Soil Information; map toolbar > Map Layers > Soil Survey (SSURGO) (US) or Soil Survey (Canada)

Soil data comes from the soil survey: the US soil survey (SSURGO) in the United States, and in Canada the province's own soil survey — Ontario, Manitoba, Alberta and Saskatchewan — with each soil series' layers from Agriculture and Agri-Food Canada. Where a province has no survey the app can read (Quebec, British Columbia, the Atlantic provinces), or the survey does not cover the field, the soils come from the national Soil Landscapes of Canada map. Only when neither answers does the field get a modelled soil (SoilGrids), shown as one soil summary and labelled modelled; confirm with a soil test. The panel always names the source it used. Once the field has a boundary and elevation, expand Soil Information on the Project tab. The panel summarizes the available soil source, texture, estimated saturated hydraulic conductivity and agricultural capability, then suggests a starting range for tile spacing, depth and drainage coefficient. The soil is fetched for the boundary you have: change the boundary — with Edit Boundary, or by drawing or loading a new one — and it is fetched again for the new boundary a few seconds later.

In the United States, turning on the Soil Survey (SSURGO) map layer draws the soil survey's map units inside your boundary. Each soil area is filled in the colour of its drainage class — the same colour as its row in the Soil Information list — with a thin outline, and carries a large soil-code label in its widest part, clear of the edges. Every soil in the list has at least one label; areas smaller than about half an acre are left unlabelled unless they are the only piece of that soil in the field. The codes match the map-unit list in the Soil Information panel, so you can see at a glance which soil you are designing over.

In Canada, the Soil Survey (Canada) layer does the same with the provincial survey's soil areas: each area is filled in the colour of its main soil's drainage class and labelled with that soil's code. Many Canadian soil areas hold two or three soils; clicking one opens a card that lists every soil in that area with its share, texture, drainage, clay and capability class, then the main soil's details. The Soil Information panel lists each soil series with its share of the whole field, its texture, its subsoil sand, silt and clay with that layer's texture (the heaviest layer starting at 25 cm or deeper, within 100 cm, named with its depth; the surface texture follows when it differs), every layer the survey records with its conductivity, its drainage class and its capability class with the limitations (for example 2W, excess water). Ontario soils also show their drainage design group and hydrologic group. Canadian drainage classes keep their own names; imperfectly drained is treated as somewhat poorly drained in the suggestions.

On the national Soil Landscapes of Canada map each area is a whole soil landscape (the map is drawn at 1:1,000,000): it lists the soils found in that landscape and their shares but does not show where each one lies inside it. The card, the panel and the report say so, and the field's shares are the landscape's mix. Treat it as a guide to which soils to look for, and confirm with a soil test.

With Soil Survey (Canada) on, Labels: Series | Capability under its row in Map Layers switches the map labels between each area's soil code and its agricultural capability class as the survey publishes it (for example 2W, or O5WD for a rated organic soil); a + means the area also holds soils of another class, an area with no rating has no label, and clicking an area explains the class and names the rating system (Alberta uses its Land Suitability Rating System; where only the national soil map is available, the Canada Land Inventory 1:250,000 map is labelled and outlined dashed).

If a provincial soil survey does not answer, the app moves to the next source and tells you once which source did not answer and which one it used instead.

While the layer is on, the Soil Legend in the lower-left corner of the map lists each soil in the field with its share of the field and its colour, followed by a key to the drainage-class colours. Click its heading to fold it to one line and again to open it; the soil layer stays on, and the choice is remembered. Click any soil area to open a card with that soil's details — texture, both conductivity numbers, drainage class, water table and the suggested starting parameters, exactly as in the Soil Information list. Click elsewhere, press Esc or use the × to close it. Clicking a drain line still selects the line, and a click that opens a soil card does not also show the point elevation.

The two conductivity numbers

Each soil shows its saturated hydraulic conductivity (Ksat) twice, because the two numbers answer different questions:

• Profile Ksat is the average over the whole profile down to the deepest drain depth, weighted by how thick each layer is. It tells you what the soil is like overall.
• Limiting Ksat is the tightest layer between the surface and the drain — shown with its layer name and depth, and marked design value. Water has to move through that layer to reach the tile, so this is the number the published guides design on, and the number Geo-Surface Pro uses.

A soil with a loose topsoil over a tight subsoil will show a high profile value and a much lower limiting value. That gap is the whole reason the two are separated: designing on the profile average would space drains too far apart on exactly the soils that need them closest.

Where the suggested spacing comes from

The suggested spacing is the narrower of two published ranges: the one for the soil's USDA drainage class, and the one for its texture and limiting Ksat. A poorly drained clay is not a poorly drained loam, so whichever reading is tighter is the one quoted. The panel prints both inputs under the numbers — for example “Narrower of drainage class (Poorly drained: 40–70 ft) and texture / Ksat (Silty clay at 0.91 µm/s limiting: 30–50 ft)” — so you can always see what set it.

Beside the range sits a worked spacing: the Hooghoudt steady-state equation solved for this soil, using the limiting Ksat, the deep end of the suggested drain depth, the low end of the suggested drainage coefficient and a water table held 1.5 ft below the surface. Hover it to see every input, including the depth of any restrictive layer the soil survey reports. When the worked spacing comes out below the quoted range, the panel prints the two numbers side by side. What you do about it is your decision.

Shrink–swell (vertic), ponded and sodic map units are flagged with a badge and a note, because those conditions slow subsoil drainage whatever the soil's texture suggests. The badge reports what the soil survey records; it does not prescribe a spacing.

All of it is a starting range read from mapped soil data, not a design. It describes the soil the survey recorded under this field and nothing else — confirm it on the ground, and on anything large, with field investigation.

For the whole field at once, Drainage settings › Tile design shows these ranges weighted by each soil's share of the field, where your current settings sit against them, and a Use these button that sets the project drainage coefficient and fills the other fields for you to save. See Design Parameters.

Lateral perforation. Each soil's envelope suggestion follows Stuyt et al. (2005), from its clay, silt and sand: a soil with 30% clay or more holds together and needs no envelope - regular perforated, and so does one with 25–30% clay when neither its silt nor its sand reaches 50%. A silty soil (50% silt or more, under 30% clay) can wash fine soil into the pipe and gets a sock; so do sandy soils, or a gravel envelope for a fine sand with silt; a balanced loam with less clay gets a sock as a precaution. With only a texture name, clay, silty clay and clay loam need no envelope. Where the texture is modelled rather than surveyed (Canada), the suggestion adds modelled texture; confirm with a soil test.

The soils' drainage classes also split the Drainage coverage figures into ground that needs drainage and well-drained ground (see Drainage Coverage).

In the PDF report, the soils section names the source and prints its licence statement; for a Canadian survey the Soil Properties table also shows each soil's capability class and its subsoil sand, silt and clay. The Soil Properties table lists each soil's profile conductivity and its limiting conductivity with the layer and depth it was read from. The Drainage Recommendations table lists the suggested spacing range, depth, drainage coefficient and envelope recommendation. What set each range, the notes about the tight layer, and any shrink-swell, ponding or sodic flags are printed as numbered footnotes under that table.

Fields with no soil survey (outside the United States and Canada, or a Canadian field where no survey answers) have no measured soil layers to read, so the conductivity is modelled from mapped texture. The subsoil band (60–100 cm) is used as the limiting value when it models tighter than the surface; when it does not, the surface estimate is halved as a conservative allowance and the panel says so. Because the whole input is modelled, this path deliberately quotes the narrower answer: the tighter of what the texture says and what the conductivity says, with the worked spacing trimming the top of the range when it comes out lower. The panel notes that the range errs narrow on purpose.

Does Auto Size size the laterals?

No. Auto Size Mains sizes mains and sub-mains only. Laterals keep the size you give them with Size and Form in the Active Design card (4" regular perforated by default); hover a lateral to see its Max DC. A lateral with a surface inlet is sized for the inlet when you place it (see Surface Inlets).

Can I change a size after Auto Size?

Yes. While Auto Size runs, change a stretch of a stepped main in the review table (see Stepped Main Sizing). Afterwards, to move, add or remove steps or change one stretch, use Edit pipe sizes on the profile chart (see Edit Pipe Sizes on the Profile). For one size over the whole run, select the run, change Size, Form or Perf in the Active Design card and click Apply changes.

What if Auto Size says a main needs a pipe larger than the largest size on the list?

That main carries more water at its grade than the largest size on your size list can take (48 inches in the US and Canada; in other regions the largest size sold there). Older versions showed "BIG!" here. If you use a larger pipe, add it in Drainage settings > Pipe Sizes as a custom size and run Auto Size again. Otherwise split the area between more mains or outlets, try dual wall, or check the drainage coefficient.

Why are some mains skipped, or why will Auto Size not start?

Mains without a grade line are skipped, and one notice at the end names them; run Best-Fit (or draw a Guided or Freeform grade) on them first. When every main is sized, Auto Size simply closes. If it will not start at all, a run is not connected to a main: see When Auto Size will not start above.

Should I use perforated or non-perforated mains?

Use non-perforated if the main only collects flow from laterals. Use perforated if the main also needs to drain soil along its length. A perforated main adds 25 ft on each side, but only over the stretches of its length no lateral covers — so a main with laterals down both sides from end to end adds almost nothing, while a main running out to the field edge with nothing on one side picks up a real strip. The review states exactly how many feet of the main were counted.

Why does dual-wall show a smaller size than single-wall?

Dual-wall pipe has a smoother interior (n=0.012 vs 0.015), allowing higher flow capacity per diameter. This results in smaller calculated sizes for the same flow rate.

Where to find it: Design tab > Simulation > Drainage simulation (or type drainage simulation in Ctrl+K)

Prefer a guided walk-through with pictures? See How to: Check the design with the Drainage simulation (Beta).

The Drainage simulation takes your tile design, the soil survey and the field's own lay of the land, rains on the field, and plays the next week hour by hour like a timelapse — once with your tile and once without it. It is a comparison: what matters is the difference the tile makes. Ground in your drained area should reach the drainage goals sooner with tile, or only with tile, if the design is doing its job; hills and other ground away from the tile should read about the same both ways. You see:

• What the tile does, at the top of the summary: what the tile gets to your goals by 24, 48 and 72 hours after the rain, one line each, against the same ground without tile. The drained area comes first, then the same three lines for the whole field, for example By 24 h · water table 1 ft down: 54 of 59 ac with tile, 29 ac without. The 72-hour line is an extra day judged against the 48-hour depth, not a goal of its own, and says so. A time where the tile gets under half the area is shown in orange. One line under it says how much of the field lies outside the drained strips and how much ground upslope sends water in.
• Side by side, with tile on the left and without tile on the right, which is how the window opens. Show what tile changes (beside the view buttons, side by side only) tints each spot green on the With tile side and red on the Without tile side, deeper where the water table is lower with tile at that hour; it plays with the timeline. Hover a spot to read it, for example 0.8 ft lower with tile at hour 72 and Reached the 1 ft goal 6 h sooner with tile.
• The water table across the field, hour by hour, on one smooth colour scale: blues while it is within the 24-hour goal depth of the surface (darkest at the surface), a lighter green from the goal depth down, darker green deeper still. While it plays the colours change smoothly from one hour to the next. Water standing on the ground (0.4 in or more) has its own teal colours by depth, light for shallow water to deep teal at 2 ft and over, so a pond filling and emptying shows even when the ground around it is soaked. A small Key in a corner of each map explains the colours; click ✕ to fold it to a Key chip and the chip to open it again.
• How full each tile pipe is, hour by hour: white while it is empty, through yellow and orange as it fills, to red when it is running full (the key shows the ramp, Tile pipes: empty → full). Tile lines at the top right of the map draws them Faint (the default, so the water under them shows), at full strength (Show) or not at all (Hide); the app remembers your choice. A main whose size steps down is coloured piece by piece. A pipe with no size set is drawn dashed white. Hover a pipe to read it, for example T1-L4: 63 % full (0.21 of 0.34 cfs). The i beside the ramp, How to read pipes running red: laterals that stay red well past the peak — often long runs through the wettest ground — are over capacity for longer than you'd want, so the water table there falls slowly. Testing narrower spacing there may help, but only if the main they empty into has room: going from 40 ft to 20 ft does little if the main is already full. If the main is red too, look at the main first.
• When the tile starts to flow and when it peaks, on a chart of the flow at the outlet, with the design flow (the drainage coefficient the pipes were sized for, times the drained area) as a line. A design with several outlets is shown all outlets combined (the title says so, for example Tile flow, all 3 outlets combined); the picker beside the title shows one outlet at a time by its main's name (T1 outlet) with its own design flow, and the tile flow line in the summary follows it. Click a run on the map to see the flow in that pipe against what it can carry.
• Pipes at capacity in this rain: one line with the tile flow (when it starts, its peak, and what the pipes were sized for), then whether this rain was heavier than that. A rain that peaks above what the pipes were sized for fills them for a while, which is what they were designed to do: This rain peaked above what the pipes were sized for, so running full for a while is expected. A pipe that runs full in a rain within its design flow is marked worth a look. Then the pipes that ran full and for how many hours; click one to see its flow.
• Wet spots: patches of a quarter acre or more that miss the 24-hour goal with the tile. Those inside the drained area say what happened there and what a test run showed; those outside it are listed apart, folded, as wet with or without tile. See Reading the wet spots below.
• The soils used: each soil in the field with the soil-survey figures the simulation took for it.
• Ponds and inlets: each pond with a surface inlet (and, on a design that targets the ponds, the ponds its tile runs through), how deep it got, when it is empty again with tile and without, and how much the inlet took. See Ponds and surface inlets below.

The note at the top of the window says so too, and adds: Shallow soil water moves down slopes toward lower ground; heavy rain can still wet hilltops briefly. Water from upslope outside the field is estimated from the field's own runoff. The Science explained link beside the Beta chip opens a panel that explains how the simulation works, in the words of the card Science explained below (Esc or ✕ closes it).

The Drainage simulation button is in the Design tab, in its own card below Tile Sizing (the Simulation chip jumps to it), and the Ctrl+K tool finder finds it. It is in Geo-Surface Pro and the demo; the free viewer shows it as a Pro feature. The button turns on by itself once the field has everything it needs; until then the line under it says what is missing:

1. A field boundary and elevation.
2. A tile main with a design grade, and at least one graded lateral connected to it — or a design that targets the ponds (below).
3. Soil data for the field: the soil survey map covering at least 80% of the field. In Canada the provincial soil survey (or the national soil landscape map, using each area's main soil) counts as the soil map. Where there is no soil map with outlines (a modelled soil only) but the Soil Information panel has a soil for the field, that one soil is used for the whole field and the window says so.
4. A design that drains enough of the field: at least 40% of the field — or a design that targets the ponds.

A design that targets the ponds runs too, however little of the field it drains: a graded run with at least one surface inlet on it, or a graded run whose perforated tile passes through a pond the Depressions layer shows (run Create Drainage Layers first). A main from the outlet to a depression with an inlet in it is enough.

When the soil data is the only thing missing (no soil survey loaded, a survey covering less than 80% of the field, or soil fetched for another boundary), the button still turns on and the line under it says so: the simulation then runs on a typical soil texture or a Ksat you enter (see Soil under The settings), and the soil survey choice is off. When no soil data loaded at all (for example the soil service did not answer), the button and the window say No soil data for this field — choose a typical soil or enter a Ksat. If something else is missing too, the line names that first, since the soil can be chosen in the window.

Run Auto Size first if you can. Without pipe sizes the simulation still runs, but it cannot check what the pipes carry and says Pipe sizes not set.

• The rain falls evenly over the field, 2 in over 12 hours unless you change it, starting at midnight.
• The start: no free water above the water table. Without tile the water table starts at the soil survey's wet-season depth (or by drainage class: very poorly drained at the surface, poorly drained 6 in, somewhat poorly drained 18 in, moderately well drained 3 ft, well drained 6½ ft). With tile, ground between two laterals, or close to a drain (within half your lateral spacing), starts at the depth of its drain, never wetter than without and never below a dense soil layer. Ground further from the tile starts as it would without tile. Hilltops start drier: ground standing well above the nearest drainage (a draw, a low spot or the field's lowest edge), where the land falls at least 2% on average on the way down to it, starts deeper — 6 in deeper for every foot it stands more than 3.3 ft above that drainage, up to 3.9 ft deeper, never deeper than 6.6 ft or below a dense layer. Flat and gently sloping ground starts as the soil survey says.
• The soil is the main soil of each soil-map unit: its surface Ksat for how fast rain soaks in, the Ksat of its layers above and below the drains for how fast water moves to the tile (worked out again as the water table moves through the layers), and how much water it holds for each inch the water table rises. Tile cannot lower the water table through a dense layer: where the tile sits below one, the water table there drops only to that layer.
• The tile drains the ground between two laterals of a bank at that bank's spacing. Ground beside only one drain, or past the end of the laterals, drains to that one drain, slowly when it is far from it. Ground lying lower than the drain beside it does not drain to it.
• The pipes carry no more than their full-flow capacity, from their size and design grade (the same calculation as Auto Size). When a pipe runs full, all the ground it drains slows down together. A run laid flat or uphill carries no water to the outlet at all.
• Water on the surface runs downhill over the field's own elevation, fills low spots and spills on; water standing soaks back in as the water table falls.
• Water down the slopes: on ground that falls 2% or more, rain water that has soaked in and raised the water table moves down the slope through the soil toward lower ground, faster on steeper ground and in soil that lets water through more easily (the soil's Ksat, taken three times higher sideways than straight down, as is usual). Where it reaches ground that is already full, it seeps out on top and runs on as surface water; at the field edge it leaves the field. The water table the field starts with is taken as settled, so only the rain's water moves. Flat ground (under 2%) is as before.
• Water from outside the field: where a flow line from Create Drainage Layers runs into the field from higher ground outside it, that ground is taken to shed as much rain water per acre as runs off the field itself, and it enters the field where the flow line crosses the boundary. Under the summary table the window says how much, for example Water from outside the field: 2.1 ac upslope at 2 entry points. Without flow lines nothing comes in.
• Surface inlets take water out of the pond they stand in, more the deeper the water over them, into the tile at their station; the pipe carries it with the tile water already in it, and what it cannot carry stays in the pond. With an inlet in the design, the water running to each pond takes the time its catchment needs to drain to it. See Ponds and surface inlets below.
• The crop and sun take up water after the rain stops, in daylight, less as the water table drops.
• Natural drainage: water also seeps down out of the profile, with tile and without: through the dense layer where there is one; in moderately well drained and better soils as fast as the deepest soil layer lets it; never more than 10 mm (about 0.4 in) a day. Wetter soils are wet because water does not leave them that way, so for them it is slow.

The same explanation as the Science explained link at the top of the simulation window.

What it is

Your field with your tile design and without it, side by side, through one rain you choose (2 in over 12 hours unless you change it), hour by hour for a week. It is a screening tool for comparing designs, not a forecast of what will happen on a given day.

How it works, step by step

• The water table starts where you chose: the soil survey's wet-season depth for each soil, deeper on hilltops well above the nearest drainage, and no wetter than the tile already keeps it.
• Rain soaks in at the soil's own rate (the Green-Ampt method). What cannot soak in runs off, gathers in low spots and spills on, with the same pond model as Ponding after rain.
• Water that soaks in raises the water table. How far depends on how much water the soil gives up as it drains (its drainable porosity): in a tight soil a little rain raises it a lot.
• Tile draws the water table down toward it: faster when laterals are closer, when the soil lets water through more easily (higher Ksat) and when the tile is deeper. This is the Hooghoudt drain-spacing equation used in DRAINMOD and in NRCS drainage design.
• Each pipe carries only so much, from its size and grade (Manning's formula). When a pipe runs full, the water behind it waits and that ground drains slower.
• Surface inlets take pond water into the pipe, more as the water over them gets deeper, as far as the pipe can carry it.
• On ground that falls 2% or more, rain water that has soaked in moves down the slope through the soil toward lower ground; where it reaches ground that is already full, it seeps out on top. Where a flow line runs into the field from outside, the ground above it sends in as much water per acre as runs off the field itself.
• After the rain the crop and the sun take water out each day (the evaporation setting), and a little drains away deep below.
• Without tile, only those natural paths take water away.

What the colours and numbers mean

• The colours show how close the water table is to the surface (the key in the corner of each map), on one smooth scale: darkest blue at the surface, lighter blue down to the 24-hour goal depth, green from the goal depth down and darker green deeper still. Water standing on top has its own teal colour, darker as it gets deeper.
• Pipes go from white (empty) through yellow and orange to red (running full). Dashed white: the pipe size is not set.
• The drainage goals: the water table at least 12 in below the surface 24 hours after the rain stops and 21 in by 48 hours, with no water standing — the Illinois Drainage Guide's excess-water criteria. You can change both.
• The summary counts the acres meeting the goals over your design's drained strips and over the whole field, with tile and without, and the difference the tile makes.
• Wet spots are patches of a quarter acre or more, anywhere in the field, that miss the goals with tile. Inside the drained area each says what happened (when the water table got down, which pipes ran full) and what a test run of the whole field showed with closer laterals or a larger pipe; the spacing tested is evidence, not a recommendation.

Reading the comparison

• The simulation compares the same field with your tile and without it. What matters is the difference: ground in your drained area should get down to the goals sooner with tile, or only with tile, if the design is doing its job. Hills and other ground away from the tile should read about the same both ways.
• The summary starts with the acres of the drained area that meet your goals with tile and without, by 24, 48 and 72 hours. Side by side, Show what tile changes tints each spot green on the With tile side and red on the Without side, by how much lower the water table is with tile at that hour; it plays with the timeline.
• Ground beyond the last lateral drains toward the one drain nearby, a simplified "one drain nearby" estimate. That is deliberate: there is not enough information to model it closely, so it gets no spacing advice, and its wet spots only say it is wet with or without tile.
• Inside the drained area the wet spots describe what happened and what test runs showed. They do not prescribe a spacing: whether closer laterals are worth it is your call, and closer laterals help little while the main they empty into is running full.

Assumptions

• Soil figures come from the soil survey (or the texture or Ksat you chose) and are taken as the same throughout each soil.
• One storm, spread evenly over the whole field.
• The starting water table comes from the survey's wet-season depth and the ground's place in the landscape.
• A free outlet: no water backing up from a ditch or river.
• Pipes are clean and carry their full capacity; they do not run under pressure.
• Each soil gives up the same amount of water per foot as it drains, at any depth.
• Evaporation runs at the rate you set.
• Clay cracking is used only if you turn it on (experimental).

Limitations

• Soil-survey Ksat can be off by several times either way: compare scenarios rather than trusting exact hours.
• Deep groundwater and the water table of the wider area are simplified.
• Frozen ground, damaged or silted tile, crop stage and field traffic are not modelled.
• The results do not, on their own, establish trafficability, crop safety or a drain spacing: the design still needs your judgement and local experience.

Sources

• Skaggs, R.W. (1980). DRAINMOD reference report. USDA Soil Conservation Service.
• Hooghoudt, S.B. (1940), with Moody's equivalent depth (1966), as in ASABE, Design and Operation of Farm Irrigation Systems (2007), ch. 9.
• Green, W.H. and Ampt, G.A. (1911); Rawls, W.J., Brakensiek, D.L. and Miller, N. (1983), Green-Ampt infiltration parameters.
• Saxton, K.E. and Rawls, W.J. (2006). Soil water characteristic estimates by texture and organic matter.
• USDA-NRCS (2001). National Engineering Handbook Part 650, Engineering Field Handbook, ch. 14: Water Management (Drainage).
• Illinois Drainage Guide (1986). University of Illinois Cooperative Extension Service, Circular 1226.
• Beven, K. (1981). Kinematic subsurface stormflow. Water Resources Research 17(5).
• Ritzema, H.P., ed. (1994). Drainage Principles and Applications. ILRI Publication 16, 2nd edition.

The strip along the bottom of the window, in three rows: the rain, the soil, and the drainage goals. Each setting has a small i beside it; click it for a sentence or two on what the setting is and when you would change it (Esc or a click elsewhere closes it). Change any of them and click Run again. They are remembered while the page is open and saved with the project (results are not saved: run it again after opening the project).

• Rain and how many hours it falls over (2 in over 12 hours unless you change it).
• Days to show: how long the simulation plays from the start of the rain (up to 14, default 7). It always runs to at least 72 hours after the rain stops, so a longer rain raises the lowest number allowed.
• Evaporation: water the crop and the sun take out of the ground each day after the rain stops (0 to 0.24 in/day). 0.16 in/day is late-spring crop water use; set 0 for a cold or bare field.
• Soil: Soil survey (as mapped) (the default) uses each soil's own soil-survey figures. Typical texture uses published typical figures for the texture you pick from the 12 soil textures (Ksat, the water the soil gives up, and how readily it takes in rain) for every soil in the field. Your Ksat uses a Ksat you type (in/hr, or mm/h in metric) for the surface and every layer, with the water a typical soil of the texture you pick gives up; the texture starts on the soil survey's main texture, else silt loam. Either way the soil survey still decides where the water table starts in a wet spring and how deep a dense layer is, and the Soil Ksat multiplier still applies on top. Typical figures are averages for the texture: a typical silty clay loam (about 0.06 in/hr) drains far more slowly than most soil-survey figures for the same soil, so try both.
• Starting wetness: Wet spring starts the water table at the soil survey's wet-season depth for each soil (shown under Soils used); Average starts it 1 ft deeper and Dry 2 ft deeper, never below a dense layer or deeper than 6.6 ft.
• Soil Ksat: Quarter (×¼), Half (×½), As mapped, Double (×2) or Four times (×4) the soil survey's Ksat (how fast water moves through soil that is full of water). Beside it, the range of Ksat across this field's soils at the multiplier you picked, for example Ksat 0.40–1.3 in/hr as mapped. The survey's figures can be off several times either way: raise it if your tile is known to run sooner and harder than the simulation shows (clay that cracks often drains faster than the soil survey says), lower it if water is known to sit longer. Try Half and Double to see how sure the answer is.
• Soil storage: Less (×½), As mapped or More (×1.5): how much water the soil gives up as the water table drops, shown as inches of water per foot of soil, with this field's range beside it. Less storage means the water table rises higher in the rain and falls faster. These are typical figures for each soil's texture, not measured on your field.
• Clay cracking (experimental): Off (the default), Some or Strong. See Clay cracking below.
• Drainage goals: the water table at least so far below the surface 24 hours after the rain (12 in unless you change it) and so far by 48 hours (21 in). See The drainage goals below.

Heavy clays that shrink and swell crack as they dry, and water moves through the cracks faster than through the soil around them; in a long wet spell they swell shut again. The Clay cracking (experimental) setting lets you try that out: Off (the default: the simulation exactly as described above), Some or Strong. It is experimental: the cracks themselves are assumed, not measured.

• Where it applies: choosing Some or Strong means you are saying this field cracks, so it applies to the whole field. The soil data only sets how deep the cracks go: where the soil survey rates the top layers high in shrink-swell (6% or more), down to the bottom of those layers and never deeper than 3.3 ft; everywhere else, including soil data with no shrink-swell figures (as in Canada), the top 2 ft (60 cm). The summary card says what was applied, for example Applied to the whole field (82 ac), zone 0–2.0 ft, and names each depth when they differ.
• What it changes: the drier those layers, the wider the cracks, and the faster water moves through the cracked layers: up to 3 times as fast with Some and 10 times with Strong. Below the drain it changes nothing unless the cracks reach that deep.
• Wetting and drying: rain first wets the dry clay and only then raises the water table. Soaked cracks close within a few hours; they open again only over days of the crop drying the soil, never just because the water table dropped.
• The start: with Wet spring the clay starts moist and the cracks shut, so it changes little. Average and Dry start the cracking layers a quarter and a half short of the water a crop can use, the cracks partly or fully open; that dry clay soaks up rain before any reaches the water table, so tile flow can start later and be smaller.
• Water does not run straight down a crack into the tile in this version.

When it is on, the summary card says where it was applied and how deep, how open the cracks were, and the window carries this note:

The setting is saved with the project like the others. Run it with cracking Off as well and compare the two.

Ground meets the goals when, 24 hours after it was at its wettest, the water table is at least 12 in down and no water stands on it, and at 48 hours it is at least 21 in down with no water standing (the depths are settings; the defaults come from the Illinois Drainage Guide). Each spot's clock starts at its own wettest hour (the most water standing on it, else its highest water table), with tile and without, so low ground that fills after the rain stops is judged from when it filled. A spot whose water table never came within the goal depth of the surface meets the goal; a spot still saturated when the run ends does not. The timeline marks the hour the field was saturated (the drained area's highest average water table) and 24 h, 48 h and 72 h after it; hover a mark to read its goal depth.

The summary card, What the tile does, shows the acres that meet the goal by 24, 48 and 72 hours (the 72-hour line uses the 48-hour depth: an extra day, not a goal), with tile and without, for two areas:

• Drained area: the ground inside your design's drained strips, the same strips as the report's Est. Area Drained.
• Whole field: all the ground inside the boundary with soil data, including ground the design does not drain; a line under the table says how much that is.

Ground with no soil data is hatched on the map and in neither. Every other part of the field is counted and can show a wet spot, whatever its soil: the simulation uses the soil survey to estimate how the soil holds and passes water (Ksat, storage, the starting water table), not to decide which ground needs drainage.

Tile does two jobs besides pattern drainage: a run to a depression that empties it through a surface inlet, and a buried pipe in place of a deep ditch you would otherwise have to farm through — it carries the surface water of the ground that runs into the low spots. The simulation plays both.

• Which pond an inlet empties: the low spot it stands in, or the nearest within about 50 ft (an inlet drawn just off a pond is taken to stand at its lowest point). An inlet with no pond near it takes the water running to it.
• How fast it takes water: its design flow (the flow saved with the inlet, typed or from its catchment) is what it takes with 1 ft of water over it; it takes more when the water is deeper and less as the pond goes down. An inlet saved without a flow is given a typical intake for its pipe size.
• The pipe: the inlet's water enters the tile at its station and shares the pipe with the tile water already in it. When the pipe runs full it takes only what it can carry; the rest stays in the pond, which then holds longer or spills on.
• Getting to the pond: with an inlet in the design, the water running to each pond arrives over the time its catchment takes to drain to it (from the longest flow path and its slope, the same method the app uses for flow lines), not all at once.
• Without tile the same pond only soaks in, dries out or spills.

The Ponds and inlets card lists each inlet's pond (and, on a design that targets the ponds, the ponds its tile runs through): how much it holds before it spills; with tile and without, how deep it got and over how much ground, and when it is empty again (no part holding more than about 0.4 in), or how much it still holds 72 hours after the rain; and for each inlet the most it took and what held it back — how fast the inlet takes water at that depth, or the pipe running full. Click one to zoom the map to it. On the map the ponds are the teal of standing water, deeper teal where the water is deeper, shrinking through the timelapse as they empty, and each inlet is a small white-ringed dot on the With tile side. The outlet chart then shows two layers: the tile's own drainage, and the inlets' water on top of it.

A design that targets the ponds (one whose drained strips cover less than 40% of the field; an inlet on a pattern design does not make it one) is read differently: the summary leads with the drained area and the ponds, and the wet spots never suggest laterals across ground the design does not set out to drain — the window says This design targets the ponds; no advice is given for ground away from its runs. A buried pipe that is not perforated has no drained strips at all; the summary then says so instead of showing a drained area.

Soils used, under the summary in the side column, opens to list each soil in the field: its map symbol and name, its acres, its drainage class (used only for the starting water table, shown as Drainage class (used for the starting water table)), and the figures the simulation took from the soil survey for it, before the Soil Ksat and Soil storage multipliers:

• Ksat, surface: how fast rain soaks in (in/hr).
• Ksat, layer the water table moves through: how fast water moves through the soil between the wet-season water table and the tile.
• Water it gives up as it drains: inches of water per foot of soil as the water table drops.
• Water table at the start (wet spring): the soil survey's wet-season depth, or by drainage class where the survey has none. Average and Dry start it 1 ft and 2 ft deeper.
• Dense layer: how far down a layer that water hardly passes begins, when the survey records one.
• Shrink-swell, when clay cracking is on.

Where the tile depth changes across a soil, the layer the water table moves through and the water it gives up are the typical value over that soil. Where there is no soil map with map-unit outlines (only a modelled soil, for example), it says One soil for the whole field and lists the Soil Information panel's soil.

With Typical texture or Your Ksat chosen under Soil, the panel says so at the top, for example Overridden: Typical silty clay loam (Ksat 0.059 in/hr, 0.48 in of water per ft of soil), and every soil shows the values actually used; drainage class, wet-spring start and dense layer still come from the soil survey. Ground the soil survey does not map is listed as Not in the soil survey, taken as somewhat poorly drained.

A wet spot is a patch of a quarter acre or more that misses the 24-hour goal with the tile. The list has two groups; click a spot to zoom the map to it.

Inside the drained area comes first. Each spot gives its size and soil, then says what happened there: when the water table reached the 24-hour goal depth with tile and without, how long the laterals there ran full after the peak of tile flow, and whether the main they empty into ran full. Where closer laterals or a larger pipe were tried, a last line in italics says what that test run showed, for example In a test run, closer laterals here helped only once T3 could carry more (tested at 30 ft, with T3 sized for 1/2 in/day). A test run is evidence, not a recommended spacing: it says what was tried and whether the spot then met the goals. Each test ran the whole field again with the change made (water running onto the spot, standing in low spots, and every pipe it shares), together with the changes tried at the other spots. Whether closer laterals are worth it is your call; read the pipes too (see How to read pipes running red above).

• The water table stayed above the goal here, with what the laterals and the main did, and the test run: closer laterals here brought it to the goals (tested at …), closer laterals did not bring it to the goals (tested down to 20 ft), closer laterals here helped only once T3 could carry more, or a larger T3 alone brought it to the goals (or did not, tested up to 1 in/day).
• Only one drain reaches this ground (no laterals on both sides) at the edge of the drained strips: a simplified "one drain nearby" estimate, so no spacing is tested there.
• The tile here is too shallow: the laterals' own depth there is no deeper than the 48-hour goal depth, so tile this shallow cannot take the water table down to that goal at any spacing or pipe size.
• The tile sits below the dense layer here: the water table cannot drop through that layer to the tile.
• The tile here is above the ground it should drain: the tile's grade line is above the ground right where it runs, and tile has to sit below the ground to drain it.
• This ground lies lower than the tile beside it: the tile cannot drain it; water there leaves only over the surface or down through the soil.
• A run is laid flat or uphill: the run named cannot carry water to the outlet, so the ground it drains stays wet.
• Water runs onto this ground or stands on it: the tile drains the soil in time for the goals, but surface water keeps it wet.
• Water stands on this ground at the 24 h and 48 h goals: a test run with closer laterals (or a larger pipe) did not clear it by the goals.

Outside the drained area: wet with or without tile comes next, folded; click it to open. Ground beyond the laterals drains toward the one drain nearby, a simplified estimate, so these spots give no advice and say only No tile here: wet with or without tile. That is deliberate: there is not enough information there to say more.

On a design that targets the ponds the list leaves out ground away from the runs (no tile there, or beside a single run), and says This design targets the ponds; no advice is given for ground away from its runs.

• With tile / Without tile / Side by side / Difference along the top. Difference shows one map of the whole run (it does not change with the timeline), with its own legend. Esc or Close leaves the window.
• Play runs the timeline (1x plays 6 hours a second); drag the slider, or use the arrow keys, to step an hour at a time. The rain shows as blue bars and the 24 h and 48 h goals as yellow marks.
• Scroll to zoom the map and drag to pan; Whole field fits it again. Hover a cell for its water table and soil, a pipe for how full it is that hour, a surface inlet for what it takes that hour. Around the field the 2D map fades into a dark grid beyond about 150 ft.
• Click a pond in Ponds and inlets to zoom the map to it, then play the timeline to watch it fill and empty; Side by side shows it with tile and without.

• One rain, one week. The outlet is assumed free: no backwater from a ditch or a full outlet.
• The soil survey's Ksat is uncertain by up to ten times; the drainage class and wet-season water table set the start.
• Surface water moves within each hour, so the timing of ponds is approximate. The time water takes to reach a pond is worked out from the longest flow path to it, the same for all its catchment.
• A field-scale screening model on 2 m (6.6 ft) cells: it shows patterns and comparisons, not a guarantee for any one spot.

Geo-Surface is a PLANNING TOOL and does not produce installation-ready construction plans. The designs, calculations, and outputs are intended for preliminary planning, budgeting, and communication purposes only.

What This Tool Does Well

• Route Planning: Helps you plan optimal drainage layouts and understand field requirements
• Area Analysis: Calculates contributing areas, required pipe sizes, and system capacity
• Budget Estimation: Provides material quantities and cost estimates for planning purposes
• Design Communication: Creates professional reports and visualizations to share with contractors and stakeholders
• Parameter Optimization: Helps determine appropriate depths, grades, and spacing for your field conditions

Critical Limitations You Must Understand

1. Soil Conditions Not Accounted For

What the tool does: Pipe capacity is worked out for pipes running full at their designed grade. Soil data from the soil survey (SSURGO in the US, the provincial soil survey in Canada, or a modelled soil where no survey covers the field) suggests starting depths, spacing and drainage coefficients, but it is mapped at a scale far coarser than your field.

Reality: How fast water actually reaches the tile depends on the soil in your field, layer by layer:

• Tight Clay Soils: Water may reach the tile far more slowly than the design rate assumes
• Sandy/Permeable Soils: Generally perform closer to theoretical calculations
• Variable Soil Layers: Can create unexpected drainage patterns and flow rates
• Compaction/Smearing: Installation damage to soil structure can reduce infiltration

What you should do: Soil testing and professional evaluation are strongly recommended for large or critical projects. Consider designing with safety factors and monitor system performance after installation.

2. LiDAR vs. RTK Elevation Accuracy

LiDAR Accuracy (used in this tool):

• Relative vertical accuracy (smooth surfaces): ±6-8 cm (2-3 inches) - excellent for understanding field slopes and drainage patterns
• Relative vertical accuracy (vegetated areas): ±10-15 cm (4-6 inches) - reduced accuracy but still useful for planning
• Absolute vertical accuracy: ±10-20 cm (4-8 inches) - less critical for drainage design
• Key advantage: Complete terrain coverage shows you the big picture of your field's topography
• Collection timing: Most provincial/state and federal LiDAR is collected during spring/fall months when vegetation is minimal, though exact capture dates are often not published and some projects may span multiple seasons
• Limitation: Historical snapshot - doesn't reflect recent changes (tillage, erosion, grading)

Ground Condition Artifacts to Watch For:

• Water in depressions: LiDAR shows water surface elevation, not ground beneath. Telltale sign: these areas appear perfectly flat in terrain profiles
• Dense vegetation: May show ground elevation higher than it actually is (canopy return instead of ground return)
• Snow cover: Can elevate apparent ground surface if present during data capture

RTK GPS Accuracy (required for installation):

• Vertical accuracy: ±2-3 cm (1 inch) or better - the gold standard for construction
• Real-time measurements: Captures current field conditions at exact drain locations
• Accounts for: Recent tillage, weather effects, surface changes since LiDAR capture
• Essential for: Final grade line design and installation depth control
• Industry standard for professional drainage installation and machine control

The Complete Picture: LiDAR's excellent relative accuracy makes it ideal for planning where drains should go and what parameters to use. RTK's superior precision and real-time measurement make it essential for determining exact installation depths and grades on installation day. They work together: LiDAR for planning, RTK for execution.

Geo-Surface Pro Tip: When reviewing elevation profiles, look for suspiciously flat areas (may indicate water surfaces) or areas where the profile seems higher than expected (may indicate vegetation artifacts). These are good candidates for extra attention during RTK field survey.

3. Smoothing and Generalization

To create feasible drainage designs, this tool applies several smoothing algorithms and generalizations:

• Grade Lines: Best Fit lays practical grades that do not follow every bump in the ground
• Routes: Runs are drawn as straight segments and do not know about obstacles you have not drawn around
• Connection Points: Lateral-to-main connections are idealized and may need adjustment in the field

Implication: The final installed system will necessarily differ from the plan due to field realities, obstacle avoidance, and installer judgment.

4. Installation Route Variations

Designed routes are intended paths, not exact specifications. Actual routes may vary due to:

• Underground utilities (power, water, gas, fiber optic)
• Rock or hardpan layers
• Wet spots or soft soil areas requiring avoidance
• Property boundaries or easement limitations
• Trees, buildings, or other permanent features
• Installer experience and equipment limitations

Best practice: Treat designed routes as guidance. Field personnel should have authority to adjust routes as needed, maintaining design intent (depth, grade, spacing) while navigating field realities.

Installable machine files written from a design built on LiDAR elevation are marked not recommended, and the app asks you to acknowledge that before writing them. Use them only once the design has been rebuilt on an applied RTK survey.

Why Direct Installation is Dangerous:

1. Elevation Data Mismatch: LiDAR elevations do not match real-time field conditions measured by RTK
2. No Field Verification: Skipping field survey means no validation of depths, grades, or feasibility
3. Liability Issues: Installer assumes full liability for systems installed without proper field design
4. System Failure Risk: Inadequate drainage performance, grade violations, or depth problems
5. Code Violations: May not comply with local regulations requiring professional engineering or permits
6. No Adaptation: Cannot respond to unexpected field conditions (rock, utilities, wet spots)

Step-by-Step Professional Installation Process

Phase 1: Planning (Using Geo-Surface)

1. Design your drainage system using Geo-Surface's planning tools
2. Determine key parameters:
   • Target depths for mains and laterals
   • Minimum and maximum depth constraints
   • Minimum grade requirements
   • Lateral spacing
   • Pipe sizes and specifications
   • Required starting depths at main inlets
3. Generate estimates for materials, costs, and project scope
4. Create reports and maps for communication with contractors and stakeholders
5. Export reference files (KML for visualization, PDF reports for specifications)

Phase 2: Field Survey (Using RTK GPS)

1. Mobilize RTK GPS equipment on installation day
2. Survey actual drain paths:
   • Walk or drive the intended routes with RTK
   • Record elevation profiles at 10-25 foot intervals
   • Mark obstacles, utilities, or problem areas
   • Verify outlet elevations and main line paths
3. Identify any route adjustments needed for field conditions

Phase 3: Final Design on the RTK Survey

1. Bring the RTK survey into the design: on the Project tab, Other elevation sources > Use an RTK survey as the ground, and re-grade, then send the design to the machine from the Deliver tab (see Exports). Or import the survey into your machine control software
2. Use Geo-Surface parameters as inputs:
   • Set target depth (from Geo-Surface design)
   • Set minimum/maximum depth constraints
   • Set minimum grade requirement
   • Set required starting depth at inlet
3. Re-grade on the RTK elevations (in Geo-Surface on the survey, or in the machine control software) using the Geo-Surface parameters
4. Review and approve the machine-generated design before installation
5. Verify:
   • No depth violations (within min/max constraints)
   • Adequate grade throughout (meets minimum requirement)
   • Reasonable starting depth at inlet
   • Proper connection depths to main lines

Phase 4: Installation

1. Install using machine control system with RTK guidance
2. Monitor installation in real-time for depth/grade compliance
3. Adjust as needed for unexpected field conditions
4. Document installed depths and routes for future reference

When Professional Engineering May Be Required:

• Large Projects: Systems exceeding certain acreage or pipe sizes (varies by jurisdiction)
• Surface Drainage: Open ditches, especially those affecting property boundaries or waterways
• Outlet Structures: Anything discharging to streams, wetlands, or public drainage systems
• Environmental Concerns: Projects near protected areas or sensitive habitats
• Legal Requirements: Some states/provinces require stamped plans for agricultural drainage
• Financing/Grants: Government cost-share programs often require professional designs

Your Responsibilities:

• Research local regulations for drainage system permits and engineering requirements
• Consult with authorities (county, watershed district, ag extension) before proceeding
• Obtain necessary permits before starting installation
• Hire qualified professionals when required or when dealing with complex situations
• Verify contractor credentials and ensure they follow professional standards

Disclaimer: The user assumes all responsibility for compliance with applicable codes, regulations, and professional standards. Geo-Surface does not provide engineering certification or professional stamps.

• Set Drainage settings before you draw. Maximum depth to what your plow reaches, minimum depth to the cover you want, spacing and drainage coefficient from the field's soils (the Use these soil suggestion and Soil-Informed Starting Parameters). See Design Parameters.
• Size for your crop. Use the Drainage Coefficient Guidelines and your local drainage guide when you run Auto Size.
• Draw every run from its outlet, and start laterals on their main.
• Leave Force connection on for laterals and sub-mains, so each one joins its main just above the bottom of the pipe.
• Before you deliver: Violations and Out of date under Find a run both read 0, and no run is listed as not connected to a main.

Use Geo-Surface To:

• ✓ Plan drainage layouts and determine system requirements
• ✓ Calculate contributing areas and required pipe sizes
• ✓ Estimate material quantities and project costs
• ✓ Determine target depths, grades, and spacing parameters
• ✓ Generate professional reports and visualizations
• ✓ Communicate design intent to contractors and stakeholders

Do NOT Use Geo-Surface To:

• ✗ Create final installation specifications without field verification
• ✗ Replace professional engineering when required
• ✗ Substitute for RTK field surveying
• ✗ Make definitive claims about system performance in specific soil conditions
• ✗ Bypass permitting or regulatory requirements

Golden Rule:

Geo-Surface tells you WHAT you need (depths, grades, sizes). RTK and machine control tell you HOW to install it given actual field conditions.

This software and its outputs are provided "as-is" without warranty of any kind, either expressed or implied, including but not limited to warranties of merchantability, fitness for a particular purpose, or non-infringement.

No guarantee is made regarding the accuracy, completeness, reliability, or suitability of any calculations, recommendations, or outputs for any particular purpose. Users are solely responsible for:

• Verifying all calculations and recommendations
• Ensuring compliance with applicable laws and regulations
• Obtaining appropriate professional review and approval
• Proper field verification before installation
• All consequences of design and installation decisions

By using this software, you acknowledge that you have read, understood, and agree to these limitations and requirements.

Where to find it: map toolbar (bottom left of the map) > Layers > Map foundation > Base Layer

The base layer is the map under everything else. Changing it never touches your field, your elevation or your design, and you can switch at any time.

United States

• Satellite Imagery (the default): Esri World Imagery with place names, roads and borders.
• Hi-Res Imagery (USGS NAIP): the USDA NAIP aerial photo, often sharper and more recent over farmland. Esri imagery shows straight away and the NAIP photo paints over it as it arrives; USGS builds each tile on request, so on a slow day that can take half a minute, and where USGS sends nothing the Esri imagery stays.
• Topo Imagery (USGS): USGS imagery blended with topographic features and names.
• LiDAR Terrain: shaded relief from the USGS elevation service, which shows every draw, rise and ditch.
• LiDAR Coverage (1 m DEM index): shades the areas where 1 m elevation (or the ~3 m product) has been published. Unshaded ground has only the coarser national elevation model.

Canada

• Satellite Imagery Only (the default): Esri World Imagery.
• LiDAR Terrain: shaded relief from NRCan's high-resolution LiDAR elevation, where it exists.
• Coarse Terrain: a lower-resolution shaded relief that covers the whole country, for ground with no LiDAR.

Other regions

• Satellite Imagery (the default): Esri World Imagery.
• LiDAR Coverage: shows where the country's national elevation survey has published elevation, in most countries as its shaded relief. The name in brackets says which survey, for example LiDAR Coverage (AHN elevation) in the Netherlands. The International region has Satellite Imagery only.

The base layer is a view setting: it is not saved with the project.

Where to find it: Layers > Map foundation, under Base Layer

• PLSS Overlay (US) draws townships and sections; Land Parcels (Canada) draws quarter sections in Manitoba, Saskatchewan and Alberta, and lots and concessions in Ontario. Both help you find field edges when you draw a boundary.
• Grid Overlay switches on a spacing grid for laying out laterals by hand; its spacing, angle and opacity show while it is on. See Annotations & Grid Overlay.

Where to find it: map toolbar > Contours (second button)

Geo-Surface draws elevation contours in your browser from the surface you are designing on — the original ground, the surface with drains carved in, or a landforming design — clipped to the field boundary. They work the same in Canada and the United States once elevation is loaded.

1. Click Contours on the map toolbar.
2. Pick a Contour interval: 0.1, 0.2 or 0.25 ft for flat tile ground, then 6 in, 1, 2, 5, 10, 15, 20, 25, 30 and 50 ft (3 cm to 50 m when you work in metric). A project saved with a 100 or 500 ft interval opens at 50 ft.
3. Choose the Line color: White or Black, whichever reads better over your base layer.
4. Choose Off to hide them.

Export KML and Export SHP save the contours you see, at the interval and on the surface shown. Each shapefile line carries its elevation in metres (elev_m) and feet (elev_ft), and whether it is a major contour (major). Contours and their interval are saved with the project.

Where to find it: map toolbar > Layers > Elevation Data

Once elevation is loaded, two layers show the ground:

• HD Elevation colours the field by height. The Elevation legend at the top right of the map gives the height each colour stands for, in your units.
• HD Hillshade is shaded relief, lit as though the sun were in the north-west, so draws, rises and ditches stand out. Leave it on under the colours for depth, or show it alone.

Each has its own tick box and a slider that sets how see-through it is; turn HD Elevation down to let the crop rows and field edges in the photo show through.

Elevation colours

Under HD Elevation, the colour ramp menu offers 16 schemes in five groups (Standard, Vibrant Scientific, Ultra Vibrant, Nature Inspired, Diverging). The default is Spectral (Purple→Yellow): purple on the lowest ground, yellow on the highest. Choose Viridis (Colorblind-safe) if you find some colours hard to tell apart. Your choice is remembered. The colours change only the look, never the elevation.

The colours are spread over your own field's range of heights, so even a very flat field shows useful variation: the lowest colour is the lowest ground in your field, not sea level.

When a ponding layer is on

While Ponding Predictor or Ponding after rain is switched on, HD Elevation and the Wetness Index are drawn at half strength so the water stands out. Switch the ponding layers off and they return to full strength.

Where to find it: Layers > Drainage Design > Color (shows while Drainage Design is on)

• By Pipe Size (the default) colours each tile pipe by its size. A row of swatches lists only the sizes used in your design; click a swatch to pick your own colour for that size. Your colours are remembered between sessions.
• By Drainage Type gives each kind of run its own colour.

• Dual-wall pipe is drawn dashed; single-wall pipe is solid.
• A stepped main shows each step in its own size colour, so you can see where the size changes.
• Surface drains always stay purple.
• Until sizes are assigned, the panel says Assign pipe sizes to see color legend.

With By Pipe Size chosen, the full-page map in the PDF report prints the same pipe-size legend.

• First look at a field: HD Elevation and HD Hillshade over the imagery, with Contours (see Base Layers).
• Finding the wet ground: add Flow Lines, Wetness Index, Depressions or the ponding layers; what each one shows is in Analysis Layers.
• Laying out the design: HD Elevation with the drains coloured by pipe size, so you see how the runs follow the ground.
• Before installation: imagery alone (HD Elevation off) to pick out headlands, obstacles and landmarks.

For a three-dimensional look at the ground and the pipes, open the 3D Terrain Viewer.

Where to find it: map toolbar (bottom left of the map) > Layers (the first button, stacked squares)

Every layer is in Map Layers. Several can be on at once.

• One line per layer: its tick box, its name, and a slider with a percentage for how see-through it is.
• Settings show only while a layer is on: a layer's own options open right under it when you tick it and fold away when you untick it — the drain Color and pipe-size swatches, the elevation colour ramp, Show drains ≥ for Flow Lines, the Wet last … Wet first slider for Ponding Predictor, the Rain slider (0.25 to 6 in) for Ponding after rain, Show under 3 in for Depressions, the Wetness Index colours and Divides between outlet groups for Drainage Basins.
• A small i beside a setting opens a short explanation of how to read it.
• Groups fold: click a group heading to fold it away. A folded group shows how many of its layers are on (for example 2 on), and the panel remembers which groups you folded.
• The ? in the panel's title bar opens this page of the manual. Close the panel with the ×, by clicking outside it, or with Esc. On a small screen the panel scrolls inside itself and keeps its title in view.

The Groups

A group appears once it has something to show:

• Map foundation: Base Layer, PLSS Overlay (US) or Land Parcels (Canada), and the Grid Overlay switch; in Quebec also Watercourses (Québec), Agricultural zone (Québec) and Declared field outlines (FADQ) (see Quebec). See Base Layers.
• Drainage Design: your runs and their Color (see Terrain Visualization), Drainage coverage (below) and Field Boundary.
• Elevation Data: HD Elevation and HD Hillshade.
• Analysis Layers: Flow Lines, Ponding Predictor, Ponding after rain, Depressions, Wetness Index and Drainage Basins, once you have clicked Create Drainage Layers. What each shows: Analysis Layers.
• Landforming Design: the cut/fill and haul layers of a landforming design. See Landforming.
• Soil Data: Soil Survey (SSURGO) in the US; Soil Survey (Canada) in Canada, with Labels: Series | Capability under it; Ag Capability (CLI) where Canadian soil comes from the national soil landscape map; Soil Texture where only a modelled soil is available. Click Soil Legend, the heading of the legend on the map, to fold the legend to that one line (the soil map stays on); click it again to open it. The app remembers which.
• Annotations & Grid: your annotations, and Overburden cuts.
• Reference Layers: your reference overlays, each with a delete button.

Your drainage runs always draw on top of the analysis layers. Reference overlays sit under the elevation colours: switch HD Elevation off to see them clearly.

Where to find it: Layers > Drainage Design > Drainage coverage (appears once the design has a tile run)

With hundreds of runs on the map it is easy to miss a corner, a headland or a pocket inside a curved main that no tile reaches. Drainage coverage shades that ground for you.

1. Tick Drainage coverage. Ground inside the field boundary that no run drains is shaded; drained ground is left clear.
2. Use its slider to make the shading lighter or darker. Hiding the elevation colours and contours makes the gaps easiest to see.
3. Read the note under it: Uncovered X ac of Y ac inside the boundary.

What Counts as Drained

• Each lateral drains a strip along its length: along each stretch, half the distance to the run beside that stretch on each side (a neighbour counts within 100 ft), or 25 ft where nothing lies beside it. These are the same widths the pipe sizing and the report's Est. Area Drained use.
• A perforated main or sub-main drains 25 ft on each side along the stretches where no lateral covers that side. A non-perforated main drains nothing of its own.
• Strips end square at the ends of each run, and only the part inside the field boundary is counted.

The overlay updates about a second after you draw, move or delete a run while it is on. It is plan coverage from the drawn layout, not a hydrology result: it does not model soil, slope or how water actually moves. The uncovered acres are close to the boundary area less Est. Area Drained; they differ where a strip reaches past the boundary or two strips overlap. A field boundary is needed.

Measured Against the Ground That Needs Drainage

An undrained knoll is not the same as an undrained low spot. When a soil survey map is loaded for this boundary (SSURGO in the US, the provincial survey or the national soil landscape map in Canada), the note also reads the soils' drainage classes:

• Poorly, very poorly and somewhat poorly drained soils are the ground that needs drainage. The note gives the share of it that is covered, for example Covered 87% of the 13.7 ac that needs drainage.
• The uncovered acres are split into ground that needs drainage, well or moderately well drained ground, and any ground with no drainage class (water, or a sliver outside the soil map).
• Largest uncovered patches lists the five biggest separate pieces of uncovered ground with their acres, their mean ground elevation and how much of each needs drainage, so a wet low patch is told apart from a dry knoll. Pieces under 0.1 ac are counted, not listed.

Without a soil map (a modelled soil only, as outside the US and Canada), the note counts all ground inside the boundary. The same happens until soils are loaded, or when the soil data on hand is for an earlier boundary. The elevation in the patch list is the existing ground surface, not a design surface.

The PDF report prints the same figures in the System Summary under Drainage Coverage: the ground by drainage class with the acres within a drained width and outside it, then the ten largest areas outside every drained width with their acres and mean ground elevation. With Soil Information unticked in the report options, or without a soil map, it prints one row for all ground.

In the free viewer, Drainage coverage is shown as a locked Geo-Surface Pro layer.

The Drainage Basins layer groups the field by where its water leaves the field: one colour for each place the water leaves. The groups follow the flow lines, so a low spot that fills and spills on down a flow line belongs to the group its water ends up in, not a colour of its own. The ground that feeds each outlet — and the line where one outlet's ground meets the next — can be read at a glance.

Inside each group the layer also shows its catchments. Walking up from the outlet along the biggest flow path, every side branch big enough where it joins is a branch catchment: the ground above that junction, which a sub-main up that branch would drain. The rest of the group is its main catchment, the ground the main itself drains. How big a branch must be depends on the field, so a large field is not cut into dozens of small pieces: 2.5 acres on a field under 80 acres, 5 acres up to 200 acres, and 10 acres on a larger field. The i beside Divides between outlet groups in the Layers panel says which applies to the field you have open.

What You See:

• One colour per outlet group, from a small palette chosen to stay distinct for colour-blind eyes. Two groups that touch never share a colour.
• Thin white lines between the smaller basins inside a group, dashed lines between a group's main and branch catchments, and a bold dark outline round each group.
• A label on each catchment with its acres. The main catchment's label also gives the whole group (for example 35.7 ac and group 48.1 ac); a branch reads 12.4 ac branch. A group with no branch has one label with its acres. Once you have a design, each label also names the run that drains most of that ground — the main, or the sub-main whose laterals cover it (for example 12.4 ac branch → T1-SM1). When no run's drained strip reaches a tenth of it, the label shows its acres only.
• Divides: the dark lines where two outlet groups meet. They have their own tick box, Divides between outlet groups, under the Drainage Basins row.
• Labels: the tick box under the divides one turns the catchment labels off and on, so the colours read clearly. The layer's slider fades the labels together with the colours.
• Patches smaller than half an acre are folded into the neighbouring group so they do not add colours or lines of their own.

Where water stands in low spots is shown by the Depressions, Ponding Predictor and Ponding after rain layers, and in the basin card below.

The Basin Card:

With Drainage Basins on, click any basin to open its card: the catchment you clicked (Main or Branch) and its acres, the outlet group's acres in all, the basin's own acres, its relief and mean slope, the run that drains that catchment, and the elevation where you clicked. Where water ponds inside that basin, the card says how deep and over how much ground, for example Water ponds up to 0.8 ft deep here (1.2 ac) before it spills; such a spot needs a surface inlet or tile under it. The depths come from the Depressions layer, so the line appears once the drainage layers have been created. Below it the card lists the basin's biggest ponds from Ponding after rain: how much rain fills each one, after what soaks in, and where it overflows next, for example 0.46 ac pond, 28 in deep: fills after about 1.8 in of rain, then overflows to the 0.30 ac pond 504 ft SE, or then leaves the field. Click elsewhere or the × to close it.

Using a Divide as Your Line:

Laterals usually stop at a divide, because the ground on the other side drains somewhere else. Wherever a tool asks you to draw a line, you can use a divide — or the dashed line between two catchments — instead:

• Herringbone: Pick a divide sits beside Draw the line for each bank's line and for the stop line across the main.
• Copy offset: Pick a divide sits beside the break-line button.
• Trim: while Trim waits for its line, the banner at the top of the map offers Pick a divide.

Click Pick a divide, then click the divide or catchment line on the map (it turns orange under the pointer). It is used exactly as a line you drew. Esc cancels. The button is available once the analysis layers exist.

• Where is it wet? Wetness Index + Depressions + Ponding Predictor, for first planning.
• Where does the water go? Flow Lines + Depressions, for outlets and main routes.
• How much rain before it ponds? Ponding Predictor, then Ponding after rain with its Rain slider.
• Did I miss any ground? Drainage coverage, with HD Elevation and contours off.
• Clean design view: all analysis layers off, for the final review and map exports.

While Ponding Predictor or Ponding after rain is on, HD Elevation and the Wetness Index are drawn at half strength so the water stands out (see Terrain Visualization).

Your project saves the drainage runs with their settings, the field boundary, the elevation, and the analysis layers (flow lines, wetness index, depressions, ponding predictor, ponding after rain and drainage basins), so they come back without being created again.

Layer switches, reference-layer opacity, contours and their interval come back with the project. Your choice of base map does not. See Project Backup for the full list.

Designing a drainage system in Geo-Surface Drain Pro follows a logical progression from initial sketching to final optimization:

Every map tool tells you what it wants while it is on. A dark banner appears along the top of the map with one line: what to click, how to finish, and that Esc cancels. For example, Draw a main says Start drawing at the outlet, then click to add points. Enter or double-click finishes. Esc cancels. and Surface inlet says to click right on a tile run.

• Finishing: a tool you draw with (a drain, the field boundary, a trim line, a break line, an area around laterals, a measurement) finishes with Enter or a double-click. A tool you click once (Split, Surface inlet, picking a main) acts on that click.
• The banner never gets in the way. A click on it goes to the map underneath, so you can place a point right under it. It goes away when the tool does.
• Guided and Freeform grade use the same banner, so the profile chart it describes stays free to click.

Tools with settings (Copy offset, Mirror, Herringbone, Respace, Update, Reconnect, Erase by area) open a panel over the map. The panel opens on the side of the map away from the runs it is working on, so their preview stays in view, and below the banner. Drag a panel by its coloured title bar to put it somewhere else. Only one tool panel is open at a time: opening another tool closes the one that was open.

Where to find it: Design tab > tool rail > Draw (its tooltip reads Draw drain)

Every drain starts the same way: you say what you are about to draw before you place a point. Click Draw on the tool rail and a small menu opens right beside it.

• Tile or Surface at the top: tile is subsurface pipe, surface is open ditches. The app remembers the one you used last.
• Tile: Main (M), Sub-Main (S, a branch main), Lateral (L, the side drains that collect the water) and Surface Inlet (I). Surface: Main Drain (M) and Tributary (T).
• Click a type or press its letter and you are drawing. The type you drew last is highlighted; Enter, or a second click on Draw, draws it again. So a row of laterals is Draw, Enter, draw the lateral, and repeat.
• A sub-main, lateral or tributary is greyed out until there is a main for it to join (its tooltip says Draw a tile main first). Draw the main first.
• Esc or a click elsewhere closes the menu without drawing.

A sub-main, lateral or tributary has to start on the run it drains into: within 30 feet of a compatible main, or nothing is drawn. See Connection Enforcement.

1. Click the outlet first. A drain is always drawn from its outlet (the low end, where the water leaves) uphill. For a main, before your first click a small tag beside the pointer shows the ground elevation under it, so you can find the low spot where the main should leave the field. The tag goes on your first click. A sub-main or lateral starts with a click on the main it joins (it snaps on).
2. Click your way up the route. Each click adds a point. Follow the flow lines up a draw for a main; for a straight lateral two clicks are enough.
3. Finish with Enter or a double-click. The run gets its name (T1, T1-L1 …), its elevations are read and its Best Fit grade is worked out at once. A surface drain then shows small arrows along the ditch, one every 200 ft (one in the middle of a short ditch), pointing the way the water runs, toward its outlet. Zoomed out, fewer arrows show, so they never crowd the ditch or its ends.
4. Cancel with Esc at any time before you finish: nothing is drawn.

Drawing Tips

• Follow the ground: switch on the flow lines and the Wetness Index in Map Layers to see where the water runs; mains belong in the draws.
• Bends: click more points where the route curves and fewer on straight stretches.
• Check the profile: select the run and open Profile Chart (bottom right of the map) to see its grade between its depth limits.

Where to find it: the Drawing Angle card at the top of the sidebar, while Draw or Extend is on

The Drawing Angle card holds a run you draw to one compass bearing, so hand-drawn runs come out parallel: along a fence line, a field edge or another lateral.

How It Works:

When you choose a type from the Draw menu, the Drawing Angle card appears at the top of the sidebar. Set the bearing before your first click on the map.

Setting an Angle:

• Type a bearing: Enter a compass bearing from 0 to 360 degrees (0 = North, 90 = East, 180 = South, 270 = West). The line will be constrained to that exact direction.
• Pick: Click Pick, then click two reference points on the map (e.g., along a tree row or field boundary). The bearing between those two points is calculated and applied automatically.
• Leave empty: If no bearing is entered, drawing is freehand (normal behavior).

During Drawing:

• The Live readout shows the current segment bearing in real time as you draw
• When a bearing is set, your cursor is projected onto the bearing line — you control the length by moving closer or farther, but the direction is locked
• Click the button to clear the constraint and return to freehand drawing at any time
• A bearing you set stays set for the rest of the session: the next Draw or Extend starts on it, until you clear it with the button

Extending Lines:

When you extend a run, the Drawing Angle card opens freehand so the extension can curve (or on the bearing you set earlier in the session, if you did not clear it). Type a bearing, or Pick one, to hold the extension on a fixed heading. The same card holds the Extend from choice; see Extend.

Where two mains are close together (in a corner, say), you can choose which one a new lateral or sub-main joins.

How to Use:

1. Select the main you want before drawing: click it on the map, or choose it in the run list under Active Design
2. Start drawing your lateral near the selected main
3. The system will prefer snapping to the selected main as long as you're within 30 feet of it, even if another main is slightly closer

If no main is selected, or the selected run is a lateral, the new run joins whichever compatible main is nearest.

Only secondary drains snap. A main or sub-main of either system is drawn exactly where you click, so two mains can run side by side or share an outlet without being joined.

When your first click lands a little off the main, the whole run moves onto it as one piece — so the angle you drew is kept exactly, and the far end shifts by the same small distance your first click was out.

Speed up your workflow with these keyboard shortcuts:

• M, S, L, I (Tile) or M, T (Surface): with the Draw menu open, start drawing that type.
• Enter with the Draw menu open: draw the highlighted type again. While drawing: finish the run, the same as a double-click.
• Esc: cancel the drawing or edit in progress; nothing is drawn.
• Ctrl+Z / Ctrl+Y: undo and redo the last change to the design (the curved arrows at the top left of the map do the same).

Where to find it: Design tab > Active Design > the run list and Find a run under it

Prefer a guided walk-through with pictures? See How to: Every tool, by where it lives.

Select a run before you change its settings or use a tool on it. There are three ways:

• Click it on the map.
• Pick it in the run list at the top of Active Design (it reads Choose a drain profile… when nothing is selected). Each run is listed under the main it drains into.
• Right-click it and choose a tool: that selects it too (see Right-click a drain).

The selected run's settings fill Active Design, its profile opens under the map, and it gets a contrasting outline on the map (its colour still shows its type or pipe size). The × button beside the list (Deselect active profile) deselects it; the circular-arrows button beside that (Refresh active profile) reads its heights again. See Troubleshooting for “Re-fetch elevations?”.

Find a Run

Under the run list, for designs with more runs than you want to scroll through:

• Search: type a name in Find a run. Case and hyphens do not matter: T1-L56, t1l56 and L56 all find T1-L56. Each match is shown under the main it drains to. Enter opens the exact name (or the first match), the arrow keys move through the list, Esc closes it.
• Browse (the tree button beside the box): the runs as a tree, grouped by main. Each main and sub-main opens and closes; the number beside it is how many runs are on it.
• Violations and Out of date: list only the runs with a depth, grade or connection violation, or the mains and sub-mains whose pipe size is out of date. The number on each is how many there are. When none has one, the list says so (No run has a violation.). The arrows beside step to the previous or next run with a violation, round the whole design.
• Up and down arrows beside the box (or the [ and ] keys when you are not typing in a box): the previous or next run on the same main or sub-main. On a main they step through the mains.
• A run you choose here opens its profile. The map moves only when that run is off screen. The finder works in the free viewer too.

Where to find it: Design tab > tool rail > Move (tooltip Move drain), or right-click a run > Move…

Use Move when a run is the right shape in the wrong place.

Steps

1. Click Move on the tool rail.
2. Press on the run, drag it, let go. One move per click of the tool.
3. If the move would strand any laterals, a confirmation names them first. Confirm to remove them with the move, or cancel and nothing changes.

One Ctrl+Z puts everything back: the run, every re-cut lateral, any removals and the re-run grades.

What Moves With It

• A drain with nothing connected moves as a whole. A lateral or sub-main on its own slides along its parent and stays connected.
• A main or sub-main with laterals: the laterals keep their inlet ends exactly where they are and get longer or shorter along their own bearing to follow. Both sides at once. Bends are kept; only the leg touching the main changes length.
• A sub-main is lengthened or shortened at its connection so it still meets its main, then its own laterals follow.
• Elevations are re-read on every run that changed, and Best Fit re-runs on those that already had a grade. Auto-sized pipes are flagged for a re-size. Names do not change.

A Move Is Refused When

• It is more than 50 ft, or more than the shortest lateral on the run. These limits apply to a main or sub-main with laterals; a run with nothing connected moves freely.
• It would remove more than about a third of the laterals.
• A sub-main would no longer reach its main.

A refused move changes nothing and tells you the limit it hit.

Where to find it: Design tab > tool rail > Reconnect (tooltip Reconnect laterals)

Hand a bank of laterals to a different main or sub-main without deleting and redrawing them.

Steps

1. Click Reconnect on the tool rail.
2. Click the corners of an area around the laterals and double-click. The runs light up.
3. Click the main or sub-main they should join. The banner counts how many reach it (12 of 15 reach it). Esc gets you out at any time.
4. Read the panel. It says which runs are cut and which are extended, names any it has to skip and why, and offers Also delete T1-SM2 if the old parent would be left empty.
5. Click Reconnect.

One Ctrl+Z puts the design back exactly as it was.

What Happens to Each Lateral

• The inlet end never moves. Only the outlet end does.
• Cut if the lateral crosses the new parent: the crossing becomes its outlet and the stub beyond it is removed.
• Extended if the new parent lies straight ahead of its outlet: the run is carried on along its own bearing until it meets it, up to 3× its length and never more than 500 ft.
• It is renamed under the new parent, taking that parent's next numbers in order along it. The laterals you did not select keep their names on both parents. Grades re-run; auto-sized pipes are flagged for a re-size. Bends are kept.

Runs It Skips

• Does not reach the new parent, even extended, or would need more than the extension limit.
• Crosses it more than once, would be left shorter than 20 ft, or runs along it instead of across.
• Is already on that run, or the run you clicked drains into it.

If more laterals cross the run you clicked than you selected, you are asked once whether to take them all.

Where to find it: Design tab > tool rail > the red Delete group at the bottom: Selected drain, Erase by area, Erase all (or right-click a run > Delete…)

Erase the Selected Run:

1. Select the run.
2. Click Selected drain (the eraser; tooltip Erase selected drain).
3. Read the question and click Delete, or Cancel. For a lateral it reads Are you sure you want to delete T2-L10?

A main or sub-main takes every run connected to it: the dialog is titled Delete Run & Connected Runs, says Deleting T1 and 14 connected run(s), lists the connected runs, and its button reads Delete All. Nothing is ever left without a run to drain into.

Erase by Area:

Remove several runs at once by drawing an area around them.

1. Click Erase by area on the tool rail. A panel opens over the map, below the banner.
2. Choose What to erase. It starts on Laterals only every time:
   • Laterals only erases the laterals and tributaries the area touches. A main or sub-main the area touches is kept, and so is everything on it. You do not have to steer the area around them.
   • Laterals and sub-mains also erases a sub-main the area touches, and every run connected to it, inside the area or not.
   • Everything it touches erases every run the area touches, and every run connected to one of them. A main takes all of its laterals and sub-mains with it.
3. Click the corners of the area on the map, then press Enter or double-click to finish. A run counts as touched when any part of it is inside the area or crosses its edge. While you draw, the runs that will be erased light up in yellow and the panel counts them.
4. Read the list. The runs are grouped by the main or sub-main they are on, with a count for each, and the touched mains and sub-mains that are kept are named. You can still change the choice; the list and the yellow runs follow.
5. Click Erase (it shows the number). Cancel, the × or Esc erases nothing.

One Ctrl+Z brings every erased run back. Hover tooltips stay off while the tool is on.

Erase All:

Erase all (the red bin at the bottom of the rail) clears every run to start again. Its dialog, Erase all runs, says This deletes every run in the design, with its grade and sizes. Click Delete All to go ahead.

You can interact with drain lines directly on the map using hover and click gestures for quick inspection and selection.

Hover Tooltips:

• Hover over any drain line on the map to see a tooltip displaying: hierarchical name, drainage type, pipe size (or stepped size range for stepped mains), length, average grade, and depth range
• Below those, the tooltip lists the reasons behind a run's warning mark. When a worst depth or grade and its limit would read as the same number, both are shown with an extra decimal, for example "worst 5.01 ft (max 5.00 ft)"
• A tile lateral that crosses a tile main or sub-main (its own included) 10 ft or more from where it joins is flagged with a red disc and white cross at each crossing, and its tooltip reads "Crosses T1 at 9+14", the station on the main it crosses. The 10 ft is measured along the lateral from its junction, so an outlet drawn a little past its own main is not flagged. Opening a project with a flagged lateral lists it once in a panel at the top right ("flagged, not blocking"), the same panel that lists runs not connected to a main. The flag is information only: nothing is changed, and sizing, the report and the exports still run. Trim the lateral back short of the main to clear it. The same flag marks a tile lateral that crosses another tile lateral, and a tile sub-main that crosses a tile main or another sub-main (its own parent included), 10 ft or more from either run's junction; each crossing is listed once. Click a crossing in the panel to zoom the map to it
• Tooltips stay out of the way of your work: none appears while a map tool is armed (drawing, Extend, Trim, a pick for Herringbone or Reconnect, an annotation or measurement) or while a dialog, popover or tool panel is open (Copy offset, the surface-inlet prompt, a confirmation). A tooltip goes as soon as the pointer leaves the map, the map is panned or zoomed, or you click anywhere, and it never covers a dialog
• With a map tool armed, a click on the map always goes to the tool. It never selects or deselects a drain and never opens an elevation reading

Click-to-Select:

• Click a drain line on the map to select it — the app switches to the Design tab, opens the profile chart and shows the run in the run list
• Choosing a run from the run list pans and zooms the map to it; a run chosen in Find a run moves the map only when it is off screen. Those are the only times the map moves without you moving it: design tools (Copy offset, Herringbone, Respace, Update laterals, Reconnect), deleting a drain, Undo and Redo leave the map where you had it. To look at what a batch tool made, press Show in its result notice
• The selected drain keeps its normal type or pipe-size colour and gains a contrasting outline, so selection never hides the colour meaning
• Clicking on a drain line suppresses the elevation point popup so you get a clean selection
• Click empty map space once to clear the current selection. The elevation point popup is intentionally suppressed for that click; click empty space again to inspect elevation
• You can also use the deselect button (×) next to the run list

Every lateral, sub-main and tributary is always connected to the main or sub-main it drains into. Only a main (tile main or surface main) can stand on its own. The design tools keep it that way:

• An edit that would cut a run off asks first. If a trim, a move, a reconnect or a respace would leave a lateral, sub-main or tributary with nothing to drain into, the tool names those runs and offers two choices: Delete them with the edit (the button names the edit, for example Delete them with the trim), or Cancel. Cancel changes nothing. A vertex edit also offers Reconnect them where it can. A run is never left floating and never turned into a main.
• Runs still within 30 feet follow the edit. A run whose outlet is still within 30 feet of its parent is moved onto it and its grade recalculated.
• One Undo. Ctrl+Z puts back the whole edit, including every run it deleted, with its name, station, grade and inlets.
• GPS survey: a lateral, sub-main or tributary starts recording only once you are within 30 feet of a main or sub-main, and its first point is placed on that main. Until then the stop button reads "Walk to within 30 ft of a tile main or sub-main to start".

Older Projects With Unconnected Runs:

A project saved by an earlier version, or a design brought in from another program, can hold a run that is not connected (for example a lateral left past the end of a main that was trimmed). The project opens normally and a panel at the top right of the map, headed 1 run is not connected to a main, lists each one with the reason, for example T1-L5 ends 74.2 ft from T1, the run it is recorded as joining. For each run choose:

• Reconnect: opens the Reconnect tool with that run already selected. Click the main or sub-main it should join, check the summary, and press Reconnect. The run is cut where it crosses that main, or extended along its own line to reach it, and takes that main's next free name.
• Delete: deletes the run (and anything connected to it). Undo brings it back.

When the last one is fixed the panel turns green: Every run is connected.

Where to find it: Design tab > Active Design > Type and Change type (shown when a lateral or sub-main is selected)

Change a lateral into a sub-main, or back, without redrawing it.

How It Works:

• Select the lateral or sub-main
• Pick Lateral or Sub-Main in the Type list and click Change type
• Promoting a lateral to sub-main allows other laterals to connect to it, expanding the drainage hierarchy
• Demoting a sub-main to lateral only works if no other lines are currently connected to it
• Main drains cannot be reassigned — the Type dropdown is only available for secondary drain types
• Hierarchical IDs update automatically after reassignment (e.g., T1-L3 becomes T1-SM2)

Geo-Surface Drain Pro names every run for you, and the name shows what it is and what it drains into: T1 is a tile main, T1-SM1 a sub-main on it, T1-L1 a lateral on T1, T1-SM1-L1 a lateral on that sub-main. The names appear on the map labels, in the run list and Find a run, in the exports and in the reports.

Main Drain Naming:

Main drains receive simple sequential numbers based on their type:

• Surface Mains: S1, S2, S3, S4...
  • First surface main you draw becomes S1
  • Second surface main becomes S2
  • And so on...
• Tile Mains: T1, T2, T3, T4...
  • First tile main you draw becomes T1
  • Second tile main becomes T2
  • Counter is separate from surface mains

Secondary Drain Naming:

Secondary drains (laterals, tributaries, sub-mains) are named based on which main they connect to:

• Surface Tributaries: S1-TR1, S1-TR2, S2-TR1...
  • Prefix shows which surface main they connect to (S1, S2, etc.)
  • TR indicates "Tributary"
  • Number increments for each tributary on that main
  • Example: S1-TR3 = third tributary connected to surface main S1
• Tile Laterals: T1-L1, T1-L2, T2-L1...
  • Prefix shows which tile main (or sub-main) they connect to
  • L indicates "Lateral"
  • Each new lateral takes the main's next free number, so the numbers follow the order the laterals were made, not their place along the main (Respace and Herringbone renumber along the main)
  • Example: T1-L15 = a lateral on tile main T1
• Tile Sub-Mains: T1-SM1, T1-SM2, T2-SM1...
  • Prefix shows which tile main they connect to
  • SM indicates "Sub-Main"
  • Number increments for each sub-main
  • Example: T1-SM2 = second sub-main connected to tile main T1

Nested Hierarchies:

The system supports multi-level hierarchies where secondary drains can connect to other secondary drains:

• Laterals Connected to Sub-Mains: T1-SM1-L1, T1-SM1-L2...
  • Shows the full chain: "connected to sub-main SM1, which connects to main T1"
  • Example: T1-SM2-L8 = eighth lateral connected to the second sub-main of tile main T1
  • A sub-main numbers its own laterals from L1, however many laterals its main has. The names are kept when you save and reopen the project.
• Tributaries Connected to Tributaries: S1-TR1-TR1, S1-TR1-TR2...
  • Rare, but system supports nested tributary connections
  • Shows parent tributary hierarchy

Connection Detection:

When you draw a secondary drain, the system automatically detects which main it connects to:

1. 30-Foot Tolerance: your first click (the outlet) has to be within 30 feet (9.1 m) of a compatible main, or nothing is drawn
2. Type Compatibility:
   • Surface tributaries → a surface main or another surface tributary
   • Tile laterals → a tile main or a tile sub-main
   • Tile sub-mains → a tile main (a sub-main can also branch off another sub-main: T1-SM1-SM1)
3. Nearest Compatible Main: if more than one is within 30 feet, the nearest one is joined, unless you selected one of them first (see Which Main a Lateral Joins)
4. Auto-Naming: the name is given as soon as you finish the run

Practical Examples:

Typical Tile System:

• T1 - Main tile drain running down center of field
• T1-L1 - First lateral drawn from T1 (north side)
• T1-L2, T1-L3, T1-L4... - Additional laterals offset from T1-L1
• T1-L15, T1-L16... - Laterals on opposite (south) side of T1
• Total: 1 main + 30 laterals = system handles T1-L30 automatically

Complex Multi-Main System:

• T1 - First tile main (west field)
• T1-L1 through T1-L20 - Laterals on T1
• T2 - Second tile main (east field)
• T2-L1 through T2-L25 - Laterals on T2 (numbering starts over at L1)
• S1 - Surface main collecting water from both tile systems

System with Sub-Mains:

• T1 - Primary tile main
• T1-SM1 - First sub-main branching from T1
• T1-SM1-L1, T1-SM1-L2... - Laterals connecting to the sub-main
• T1-L1, T1-L2... - Laterals connecting directly to main T1
• Clear differentiation: T1-L5 connects to main, T1-SM1-L5 connects to sub-main

Where Hierarchical Names Appear:

• Run list and Find a run: runs grouped under their main (S1, S1-TR1, S1-TR2, T1, T1-L1...)
• Map Labels: Each line labeled with its hierarchical ID
• KML, Shapefile and Machine-File Exports: Line names in exported files
• PDF Reports: Materials list and flow calculations organized by hierarchy

Every tile run already on the map drains a strip of ground on each side: half the distance to its neighbour, or 25 ft on a side with no neighbour. That is the ground the Drainage coverage overlay leaves clear. Herringbone, Copy offset, Mirror and Aligned lateral keep new laterals out of it, so a new bank never doubles up on ground that is already drained.

• Walking out from the main, a new lateral stops where it would run into an existing run's strip. A side with no neighbour counts as half the new lateral's spacing, so no new lateral is laid within half a spacing of an existing one. One farther away is kept even where the strips overlap a little, because leaving it out would leave a gap wider than the spacing.
• The main the new lateral hangs on does not count, and neither does the first spacing out from the main, where laterals on both sides of a main always meet.
• A lateral that would start inside drained ground, or be left shorter than the Minimum lateral length, is not laid.
• The result says so in one line, naming the runs that already drain that ground: “6 shortened where the ground is already drained by T1-L1, T1-L2 and T1-L3”. Show lights up those laterals.
• To overlap on purpose, untick Keep out of drained ground in the Herringbone, Copy offset or Mirror panel, or in the Aligned lateral banner at the top of the map. It is on each time the app opens.
• A lateral you draw by hand is never changed. If it runs through drained ground for at least the minimum lateral length, a notice says so, for example T2-L113 overlaps drained ground · 50 ft spacing, with Show for the run it overlaps.
• Boundary setback (10 ft) and Minimum lateral length (20 ft) are in Drainage settings › Tile design › Layout Tools.

Where to find it: Design tab > tool rail > Offsets (tooltip Copy offset), or right-click a lateral, sub-main, tributary or main > Copy offset…

Draw one lateral, then copy it across the field at a set spacing. Every copy is connected to the main and graded. Select a main instead and Copy offset lays copies of the whole main beside it, each a new main of its own (see Copying a main below).

Steps

1. Draw one lateral (the seed) from the main out to where it should end.
2. Select it and click Offsets on the tool rail. The Copy offset panel opens beside the map.
3. Draw the break line: under Break Line (Optional) click Draw break line, click along where the laterals should stop (the field edge, the headland, the edge of wet ground) and double-click or press Enter. The panel comes back showing Break line drawn with Clear beside it, and To break line is chosen for you. Once the drainage layers are built, Pick a divide beside it uses a divide between two drainage basins as the break line instead.
4. Distance (ft): the on-centre spacing, 5 to 500 ft, prefilled from your lateral spacing default. It is measured on the ground, square to the lateral, wherever the copy lands along the main. Herringbone, Respace, Mirror and Aligned lateral lay their spacings, angles and lengths the same way.
5. Direction: Towards Outlet, Towards Inlet, or Both Ways: the copies are laid outward from the seed in both directions in one go.
6. How Many: # Offsets (a number; with Both Ways, that many on each side), Fill to end of main, or To break line: the line decides how many copies are made, as many as still reach it. Until a break line is drawn that row reads draw a break line first.
7. Check the preview on the map, then click Create Offset Copies. All copies are graded in one pass and one profile chart appears at the end.

One Ctrl+Z removes the whole batch, both sides of a Both Ways batch included.

Preview: while the panel is open, the map shows what Create will lay. Each copy is a dashed green line; the part cut off a copy (10 ft inside the field boundary, where it would run into drained ground, or 10 ft short of a run it would cross) is a faint dotted line beyond it; and a copy that would not be drawn is marked with a red × where it would join the main. The panel sums it up (Copy offset on T1: 6 copies to lay · 53 ft apart · both ways · to the break line) and lists the same lines the notice will carry, each with Show. The preview follows every change you make in the panel and to the break line, and Create lays exactly what it shows.

Copying a main

Select a tile main or a surface main and open Copy offset. The copies run alongside the whole main, every bend included, at the distance you type.

1. Distance (ft): how far each copy is from the main, measured square to it on the ground. A second copy on the same side goes twice as far out, and so on.
2. Direction now names the main's two sides by compass, for example North side, South side or Both sides. (On a main that nearly loops back on itself it reads left and right, looking up the main from its outlet.)
3. How Many: # Offsets only, up to 50 a side. Fill to end of main and To break line are for laterals; with a main selected the panel asks for a number instead.
4. Check the dashed preview, then click Create Offset Copies.

• Each copy is a new main with the next free name (T2, T3 … for tile, S2, S3 … for surface). It has its own outlet at its first point, the end beside the original main's outlet, and does not join any other run. It takes the original main's depths and grade settings (and a tile main's pipe), and is graded by Best Fit.
• Check every new outlet. A copy's outlet is simply where the copy starts, not a real outlet. The notice after Create always says so (“Check the outlets of T2 and T3: each is placed at the copy's first point, not on a real outlet”), and its Show lights the outlets on the map. Move, extend or trim each new main to a real outlet as needed.
• With a field boundary in the project, each copy keeps 10 ft inside it at both ends: a copy whose outlet end lies outside the field starts 10 ft inside where it enters the field. A copy that would keep less than 20 ft inside the field is not laid.
• A copy never crosses another run: walking from its outlet, it stops 10 ft short of the first main, sub-main or lateral it would cross (the original main's own laterals included), and the notice names that run. If that leaves less than 20 ft, the copy is not laid and the notice says which run was in the way.
• Only the main is copied, not its laterals. Lay the new main's laterals afterwards with Copy offset, Mirror or Herringbone.
• One Ctrl+Z removes every copy of the batch, both sides included.

Good to Know

• Copies take the main's next free numbers: from the seed T1-L1 they are T1-L2, T1-L3 …
• Every copy joins the same main as the template. A copy that would cross another main or sub-main stops 10 ft short of it, and the part beyond is left off; it is never handed to that main. Copies that would fall past the end of the main are not drawn, and with a number of offsets a notice tells you how many.
• With a field boundary in the project, every copy ends 10 ft inside it. A copy that would keep less than 20 ft inside the field, or that would join the main outside it, is not drawn. The notice counts the copies clipped at the boundary and the ones not drawn.
• Every copy stands at exactly the spacing you typed from the one before it. On an angled main the junctions sit further apart along the main than the spacing; the laterals themselves are at the spacing you asked for.
• Laterals at a tee or a main's end are flagged. A copy whose junction lands within 10 ft of a tee (where a sub-main joins the main) or of either end of the main or sub-main is still laid at exactly its spacing, and the notice flags it: “1 lateral joins T1 within 10 ft of the T1-SM1 tee - check it”. Show lights it up. The flag is only a note in the notice; nothing on the run is marked and nothing is blocked. Decide whether to leave it or slide it a few feet along the main with Move (a lateral right at the outlet end of a main is often better a few feet up from it); closing the notice clears the highlight. Respace flags the same cases.
• Laterals on the other side of the main do not move the copies. To make two banks face each other, start them from templates that are in line (Mirror across the main or Aligned lateral) and copy both at the same spacing: they stay in line to the last copy.
• On a main that winds, each copy joins the main a little further along from the one before. Where the main turns away from the copy direction, so that the next copy could only join it far further down, the copies stop there and a notice says after which lateral.
• Copies carry on round a bend of the main, each one an exact parallel copy of the template. A copy that cannot be built accurately there is skipped and the copies carry on past it: one that would meet the main at less than 15°, or whose line would cross the main a second time. The notice lists the skipped copies by reason with where they are along the main, for example “3 skipped at 1,920-2,020 ft: they would meet T1 twice.”
• Carry on to other mains and sub-mains the laterals reach (in the panel, ticked by default and remembered while the app is open). When the copies run off the end of the template's main or sub-main, they carry on at the same spacing onto whichever main or sub-main their line reaches next — up the main a sub-main drains into, across to another sub-main, or onto a separate main — for as long as they still reach the break line (To break line) or fit (Fill to end of main). Where a copy's line crosses another main or sub-main of the same system, it becomes one lateral per run it crosses: the part up to 10 ft short of that run hangs on the run it started from, and the part beyond hangs on the run it crossed, so the ground between the two is drained too. A copy that would cross an unrelated main while its own main still runs beside it stops 10 ft short of it instead. A copy whose place at the spacing would join within 10 ft of where a sub-main meets its main is moved along that run just far enough to be 10 ft clear, keeping its direction; the copies after it are back at the exact spacing, and the notice says so (“1 moved 7 ft up T1 to clear the T1-SM1 tee.”). The notice lists each hand-over with its station, for example “The copies carry on across mains: T1-SM1 to 0+16 -> T1 from 4+00.”, and where and why the copies ended. Untick it to keep every copy on the template's own main or sub-main. It works for straight templates; a bent template's copies stay on its own main.
• A copy never crosses a main or sub-main or another lateral — a neighbouring bank, the template itself, or a copy made earlier in the same batch: it stops 10 ft short of it and a notice names it. Two runs that meet within 10 ft of both their junctions (teeing into the main side by side) do not stop each other. A copy that would be left too short to be a run is not drawn, the notice says where, and the copies carry on past it.
• A copy that would run alongside an existing lateral, within half the spacing of it for more than a quarter of its length, would drain ground that lateral already drains. It is not drawn, and the notice names the lateral: “The copy after T1-L65 was not drawn: it would run 15 ft from T1-L42.”
• Copies keep out of ground an existing run already drains (see Keep Out of Drained Ground): a copy that would run into it is shortened there, and one that would lie inside it is not drawn; the notice counts both and names the runs. Untick Keep out of drained ground in the panel to overlap on purpose.
• Each copy gets the template's pipe (size and perforation) as well as its depths and grade.
• The template itself is never changed by Copy offset.
• A bent or curved template is copied leg by leg. Copies stop when the inside of a bend closes up.
• The break line clears after the copies are created. Click Clear beside Break line drawn to draw a new one earlier.
• When every copy you asked for is made, no message appears. When copies are stopped, shortened, skipped or not drawn, one notice at the top of the map says so: a headline (“Copy offset on T1: 28 copies laid · 50 ft apart · both ways · fill to end of main”), then one line per kind of outcome with a count and a Show button that highlights exactly those laterals, or the places where copies were not drawn, and zooms to them if they are off screen. The full list, lateral by lateral, is behind Details. Respace ends with the same kind of notice. The notice stays until you close it with the × or a click on the map (or Esc), and showing it never takes the app out of full screen. The same goes for Mirror, Aligned lateral, Herringbone, Respace, Reconnect, Update laterals, Trim, Split, Move and Auto Size.
• When the other side of the main already has laterals, the new tees are compared with the tees opposite them. In a finished design they face each other, so one hole over the main serves both trenches. If they have drifted more than 1 ft apart, the message at the end says by how much and names the worst pair, for example “Tees drift up to 4.0 ft from the laterals opposite (T1-L85 is 4.0 ft from T1-L55).” When they line up, or nothing is opposite, it says nothing.

Where to find it: Design tab > tool rail > Mirror (tooltip Mirror across the main), or right-click a lateral > Mirror across parent…

Put a lateral's twin on the other side of the main, from the same station, without drawing it — one lateral, a few you pick, or a whole bank at once.

Steps

1. Select a lateral of the bank.
2. Click Mirror on the tool rail. The Mirror across the main panel opens, and a dashed preview shows every new lateral before anything is drawn.
3. Under Mirror, choose what to copy:
   • This lateral: the one you selected.
   • Selected laterals: click Select on map, click the corners of an area around the laterals you want and double-click to finish. The panel comes back with the laterals on this main that the area touches picked and highlighted. Esc brings the panel back without changing the pick.
   • All laterals on T1, this side: every lateral on the same side of the main as the one you selected — the whole bank.
   Each lateral gets its own twin at its own station, with its own length, pipe and design settings.
4. Under Way across, choose how it crosses: Straight through keeps each lateral on one straight line across the main (same compass bearing), so the two sides share one tee and the rows run straight across the field; Mirrored angle reflects the lateral in the main instead, for a herringbone look. With Mirrored angle you can type a different Angle to the main, 1° to 179°, measured on the ground from the main's direction. It starts at the lateral's own angle each time.
5. Under Length, choose how long the twins are:
   • Same length as this run: each twin is as long as the lateral it copies.
   • To a break line: click Draw break line (it reads Redraw break line once one is drawn), click along where the new laterals should stop (the field edge, a headland, the crest between two draws) and double-click to finish. The panel comes back. A break line you drew for Copy offset is used too. If you turn GPS on while drawing it, the panel closes instead (GPS on means no edits) and nothing is mirrored.
   • To the field boundary: each twin runs to the edge of the field. Offered when the project has a boundary.
   To a break line or the boundary, each twin is one straight run from the main on the exact bearing, ending where it first meets that line, so the lengths follow the line instead of copying the other side.
6. Check the dashed green preview. Where a twin has to stop short, the part it gives up shows as a faint dotted line; a twin that cannot be laid shows in red. For one lateral the panel gives its length and angle; for several it lists how many will be laid, stopped short or left out, each with Show. Click Mirror at the foot of the panel (it reads Mirror 7 when seven twins will be laid).
7. Each twin is drawn, connected at its template's station, given that template's pipe (size and perforation), depths, grade, connection offset and tie, and graded. Mirroring several at once is one step: one Ctrl+Z undoes them all, and one notice at the top of the map sums it up (“Mirror on T1: 6 twins laid”), with Show beside each line to find those runs on the map.

Your choices of crossing and length are remembered for the next run. Then Copy offset each bank at the same spacing, and every pair of tees faces each other.

Stops short: a tile lateral or sub-main never crosses another tile lateral, main or sub-main. Whatever length you chose, the twin stops 10 ft short of the first one it would meet (a lateral touching it within 10 ft of both junctions is the junction), and a notice names it: “T1-L62 stopped 10 ft short of T1-L21, where it would cross it.” If that leaves less than 20 ft, nothing is drawn and the panel says why. Copy offset follows the same rule.

Drained ground: with Keep out of drained ground ticked (the default), a tile twin also stops where it would run into ground an existing run already drains; the panel and a notice with Show name those runs. Untick it to overlap on purpose.

Where to find it: Design tab > tool rail > Aligned (tooltip Aligned lateral)

Two mains, one each side of the field, and the laterals on the second main must carry on the lines of the laterals on the first. This draws the first run on the second main exactly on the line of one you already have. Copy offset from it and the two banks stay in line all the way down the field.

Steps

The banner at the top of the map counts the steps (Step 2 of 3 — …) and says which click comes next; Esc cancels at any step.

1. Click Aligned on the tool rail.
2. Click a lateral on the first main. Pick one in the middle of the bank that clearly reaches the second main.
3. Hover the second main. A dot and a dashed line show where that lateral's line crosses it. Click the main to accept. If it turns red, the line does not reach it and the banner says why. Pick another lateral.
4. Click once out along the dashed line to set the far end, then double-click or press Enter. The side of the main you click decides which way the run goes. If the line crosses a main or sub-main further out (the same main included), the run stops 10 ft short of it and the banner says so. If that would leave less than 20 ft, nothing is drawn and a notice names the main in the way. The run also stops where it would run into ground an existing run already drains, and the banner names those runs; untick Keep out of drained ground in the banner to overlap on purpose.
5. Copy offset from the new run at the same spacing as the first bank.

The result is an ordinary lateral: named under its main, graded once that main has a grade, undone with Ctrl+Z. A bent lateral can be used too; the leg nearest the second main sets the line.

A lateral that crosses its own winding main

When a main winds, a lateral can run out from it, cross it again further along, and carry on beyond. A lateral cannot cross a pipe, so split it into two runs on the same line: one each side of the main.

1. With Trim, draw a short cut across the lateral just before it reaches the main again (a few feet short of it). The part beyond the cut is removed.
2. Click Aligned lateral and click the trimmed lateral.
3. Hover the same main where the lateral's line crosses it again. The dot and the dashed line show the crossing. Click the main there.
4. Click once on the far side of the main, then double-click. The new run starts on the main at that crossing, exactly on the trimmed lateral's line, and is named as that main's next lateral.

If the line crosses the main in several places, the crossing nearest where you click is used. A click on the main where the lateral already joins it (within 10 ft along the main) is refused: the banner says That is where T1-L42 already joins T1. Click T1 where the alignment crosses it again, or another main.

Where to find it: Design tab > tool rail > Herringbone (tooltip Herringbone laterals), or right-click a main or sub-main > Herringbone…

No seed lateral needed. Pick a main or sub-main, set a spacing and an angle, and the whole pattern is laid out off it, one bank or both at once. The spacing is on centre: every lateral on a bank is exactly that far from its neighbour, measured square to the laterals, on a straight main or a curved one.

Steps

1. Give the main its grade first (Best Fit). Laterals tie to the main's invert.
2. Select the main or sub-main, then click Herringbone on the tool rail. If nothing suitable is selected, click the main on the map when asked.
3. Fill in the panel:
   • Spacing, on centre — the distance between neighbouring laterals, square to them. Prefilled from your lateral spacing default. The line under it says how far apart that puts them along the main (50 ft at 45° is every 70.7 ft along it).
   • Angle to the main — 90° is square, 45° is the classic lean. Measured toward the inlet end.
   • Sides — both, left or right. Left and right follow the main's direction from outlet to inlet.
   • Other side — Mirrored, Straight through (same compass bearing, for a diagonal main), or Its own angle.
   • Start station — distance from the outlet to the first lateral. Prefilled at one spacing.
   • How far up the main — To the end of the main, or Stop at a line I draw: click Draw the stop line across the main and draw a short line across the main where the last laterals should be (or Pick a divide once the drainage layers are built).
   • Keep out of drained ground — on by default: each lateral stops where it would run into ground an existing run already drains (see Keep Out of Drained Ground). The ground it gives up shows as a faint dotted line in the preview.
   • Lateral length — set for each bank on its own: To the field boundary (each lateral stops the Boundary setback inside the boundary, 10 ft unless you change it in Drainage settings), To a line I draw (click that bank's Draw the line and each of its laterals runs out until it meets the line), or Fixed length. So one bank can run to a headland line while the other runs to the boundary.
4. Check the dashed green preview on the map and the result box in the panel. Its first line says how many laterals will be laid, the spacing, the angle and “no crossings”. Under it is one line for each thing worth knowing, with a count: the pairs that share one hole and the longest dogleg, laterals laid alone at their own stations, laterals shortened where they met another run, laterals shortened where the ground is already drained (naming the runs that drain it), laterals that end short where the main curves back across them, laterals that missed your line and run to the boundary instead, laterals too short to lay, and the sections a bending main is laid in, with the stations where they join. Click Show on a line to light up those laterals on the map; click it again to clear it. Details lists every lateral.
5. Click Apply. Runs are named T1-L1, T1-L2 … along the main and graded in one pass with one chart at the end. If anything was shortened, skipped or laid in sections, the same lines appear in a notice at the top of the map, each with its Show button; closing the notice clears the highlight.

One Ctrl+Z removes the whole pattern.

Curved mains

• Each bank keeps one bearing, taken from the straight line from the start station to where the pattern ends on the main (not from each bend), so the laterals on a bank stay parallel and on centre.
• Where the main bends more than 30° away from that line, the pattern is laid in sections, each with its own bearing. The summary names where the sections join. At a join the laterals of the later section stop 10 ft short of the earlier section's, and the first lateral of the new section is one spacing from the last lateral before the join. On the outside of a sharp bend the two sections open out from each other; check that ground and add a lateral by hand if it needs one.

Both sides, one hole. With Sides set to Both and the other side Mirrored or Straight through, each lateral is paired with the nearest one across the main and the pair tees in at one hole, so the trench runs out each way from a single dig. On a straight main the two already meet the main at one station and nothing changes. Where the main curves, the two lines meet the main a little apart; the hole goes midway between them and each lateral makes one short bend from the hole onto its own line, so both banks stay exactly on centre and parallel. The bend is as close to the main as it can be while the short leg leaves the main at 15° or more and turns no more than 45°. A lateral stays at its own station, on its own, when there is no lateral near it on the other side (within half a spacing of the hole) or when a leg would cross another run or come inside the boundary setback. The result box says how many pairs share a hole and the longest dogleg; Details names that pair and its station. Its own angle, Left only and Right only lay each bank on its own. Respace, Move and Copy offset keep working on a paired bank: they read each lateral by its own straight line, so Respace sees the bank at its true spacing, Move keeps a short bend where it still fits and otherwise straightens the lateral onto its own line, and a copy is laid straight on its line without the bend.

Good to Know

• Nothing crosses. A lateral stops 10 ft short of any run it would cross: another main or sub-main, an existing lateral, a lateral laid earlier in the same pattern, or its own main where it meanders back. It stays connected to the main it was laid off. The panel shows the crossing count, and Apply stays off unless it is 0.
• A lateral left shorter than the Minimum lateral length (20 ft unless you change it in Drainage settings) is not laid. Show on that line marks where each one would have started; Details names them all.
• If a bank is set to To a line I draw and some of its laterals never reach the line, those laterals run to the field boundary instead, and the summary says so. None are left out without a word.
• Options that do not apply are greyed out rather than hidden, so the panel never moves under the pointer.
• The lines you draw are cleared once Apply has laid the pattern, and when you put the tool away (Esc, the ×, the toolbar button, or a click on the map). If Apply lays nothing, they stay so you can adjust them.
• Afterwards they are ordinary laterals: Respace, Update, trim or delete them as usual.

Where to find it: Design tab > tool rail > Update (tooltip Update laterals)

Active Design changes one run. Update laterals changes a group in one go.

Steps

1. Click Update on the tool rail. It starts on All laterals in the project.
2. To pick some: click Select a group on the map, click the corners of an area around them and double-click; the panel then offers Selected (6). Or choose All laterals on T1: it names the main the runs you picked share, or, when you picked none, the main of the run selected in the run list (a lateral's main, or the main itself). Each choice shows how many laterals it covers.
3. Fill in only the boxes you want changed. A blank box leaves that value alone. A grey hint shows what the group has now; 3 values means they differ. Dropdowns start on Leave unchanged.
4. Click Apply. Best Fit runs are re-solved; hand-drawn grades keep their profile and are re-checked. You get one line saying what changed.

What you can change: target, min and max depth; min grade; max bend (when enforcement is on); force connection; connection offset; pipe size; perforation.

One Ctrl+Z puts every run back.

Where to find it: Design tab > tool rail > Respace (tooltip Respace laterals)

A bank is down at 50 ft and you want 40. Respace lays that bank out again at the new spacing.

Steps

1. Click Respace on the tool rail.
2. Click the corners of an area around one bank and double-click. The runs light up. They must all hang on the same main or sub-main. If the area caught laterals on both sides of it, the panel asks which side to respace — for example Respace the 13 on the NW side or the 9 on the SE side? — with one button per side; pick one and carry on.
3. Type the New spacing. When you stop typing, the panel tries every new place the same way Apply will and says what will happen: 7 laterals at 40 ft: keep 2, add 5, remove 4. (keep means an original already on the new spacing stays where it is). If some places cannot take a lateral, it says how many and why before you apply — for example 1 position cannot be laid: it would run in ground already drained by T1-L7. Apply still lays all the others. A lateral that lands within 10 ft of a tee or the end of the main is laid at its spacing, and the panel says to check it.
4. Click Apply. The bank is renumbered along the main and graded in one pass. Apply lays exactly what the panel said; if a place could not take a lateral, the result message names the reason and Show marks each such place on the map.

One Ctrl+Z undoes the whole respace.

Good to Know

• The bank never grows: the new layout covers only the stretch you selected.
• The new grid starts at the first run downstream. Originals that land on it are kept, runs are added in the gaps, and the rest are removed. Five runs at 50 ft respaced to 30 ft: keep 2, add 5, remove 3.
• An original counts as on the grid when it is within 1% of the new spacing of its place (half a foot at 50 ft). A hand-drawn bank that is roughly 50 ft apart is moved onto exact 50 ft gaps; the tool says a bank is already at that spacing only when every gap is within that 1%. If a gap still ends up outside it, the result message gives the real range of gaps. The bank keeps its length: its last lateral is never dropped, and if its new place would be past the end of the main it stands at the main’s end instead.
• Each added run copies its nearest original: shape, length and design parameters. Its grade is solved fresh. The far ends of the originals set where the new runs end.
• It changes spacing and nothing else. Use Update laterals for depths, grade or pipe, in either order.

Where to find it: right-click any run on the map

Prefer a guided walk-through with pictures? See How to: Every tool, by where it lives.

Right-click a drawn drain to see its name, type, length and the tools that apply to it, without going to the tool rail. Opening or dismissing the menu leaves your selected run and unapplied settings alone. Choosing a tool selects the run you pointed at.

Every drain offers View profile, Best Fit, Edit vertices, Extend…, Move…, Split…, Split here and Delete…. Every drain also offers Copy offset… (a main is copied whole as new mains, any other run as copies teeing into the same parent); tile mains and sub-mains offer Herringbone… and Auto Size this run; connected laterals, sub-mains and surface tributaries offer Mirror across parent…; tile mains, sub-mains and laterals offer Add surface inlet here.

Move and Split still need their map gesture: drag the run to move it, or click the split point after choosing Split. Delete keeps its confirmation, including any connected drains, and Undo restores a confirmed deletion.

Split here splits the drain you right-clicked at the point you clicked, with no further gesture. The menu shows the station it will use: the split lands exactly where you clicked on that drain (a click on its very end moves in to the next profile point), and the pieces are named as Split names them. Each item shows its own station. Add surface inlet here opens the surface-inlet prompt on that drain at the point you clicked. Give the inlet's flow as Flow required, or work it out From its catchment. For a lateral, calculate and accept the pipe size (Calculate Lateral Tile Size); for a main or sub-main, choose Add Inlet Flow. One Undo takes back either.

Unavailable tools show the reason. Choose View profile first if a tool asks you to select a drain. The free viewer keeps authoring tools locked with a Pro explanation; View profile remains available.

Use the arrow keys, Home or End to move through the menu, and Enter or Space to choose. Escape, Tab or a click outside closes it. With the map focused, Shift + F10 or the Menu key opens it for the selected drain. Right-click leaves an active drawing or editing tool alone.

Where to find it: Design tab > tool rail > Edit geometry group: Move, Vertices, Split, Trim, Extend

Beyond drawing, Geo-Surface Drain Pro has tools to lengthen, shorten and cut runs. Move and Vertices are in Managing Drainage Lines.

The Extend tool lengthens a drain by drawing more vertices. Any drain can be extended from its inlet (upstream) end. A main with no parent can also be extended from its outlet end, for example when the outlet needs to reach farther past the field edge. Nothing else is redrawn: the laterals stay where they are and keep their names.

Using the Extend Tool:

1. Select the run you want to extend (click it on the map or pick it in the run list).
2. Click Extend on the tool rail (tooltip Extend selected drain), or right-click the run > Extend…
3. Choose the end: the Drawing Angle card at the top of the sidebar gains a first row, Extend from: Inlet end / Outlet end. Inlet end is the default. Outlet end can be picked for a main or surface main that has no parent; for a lateral, sub-main or tributary it is greyed out and says why (its outlet is its connection). Type a bearing in the same card to hold the extension on a fixed heading.
4. Click new points out from that end; a blue line follows the pointer.
5. Finish with Enter or a double-click.

What Happens After Extension:

The system automatically processes the extended line:

• Elevation data: Read again for the whole extended line
• Grade: A Best Fit run is solved again over its full length. A Guided or Freeform run keeps the elevations you set and is re-checked against the depth limits
• Connection validation: If a secondary drain, its connection to the main is validated
• Profile refresh: One chart at the end shows the extended line with its grade line

Extending the Outlet End of a Main:

The new vertices go in front of the old outlet, so the old outlet becomes a point along the run and every station on the main moves upstream by the added length (L). What shifts and what never changes:

• Laterals and sub-mains: Stay exactly where they are on the map and keep their names. Their connection stations grow by L, and any lateral tied to the main's invert is re-solved against the new grade
• Surface inlets: Markers do not move; their stations grow by L
• Pipe schedule: A hand-set schedule gains a new first reach from 0 to L in the old outlet size. An Auto Size schedule is marked stale, so run Auto Size again
• Fixed start depth: Applies at the new outlet. The outlet transition distance is measured from there too
• Profile chart: Stations read L farther along than before

The extension may not cross another main or sub-main at either end: a crossing is refused, a notice says which run is in the way, and nothing changes. One Undo (Ctrl+Z) puts the run, its stations, inlets, schedule and grades back.

Where to find it: Design tab > tool rail > Trim (tooltip Trim drain lines)

The Trim tool shortens runs along a line you draw across them, for example to square off the far ends of a bank back from a waterway or a field edge. It keeps the outlet (downstream) part of each run and removes the part beyond the line.

Using the Trim Tool:

1. Click Trim on the tool rail. Nothing needs to be selected.
2. Click where the cut line starts, and along it if it bends. It can cross as many runs as you like.
3. Double-click (or press Enter) to finish. Every run the line crosses now ends on it and is graded again over its new length. The map keeps its scale and position.

Once the drainage layers are built, the banner also offers Pick a divide: click a divide between two drainage basins and it is used as the cut line.

A trimmed drain keeps every bend on the part you keep, and its length is the same after you save and reopen the project.

A drain with a Guided grade keeps it: the grade points on the part you keep stay where you put them, the new end takes the grade the old line had there, and the drain is still Guided. If the kept grade now breaks a depth limit, the violation is shown; the grade is not replaced. Extending a Guided drain at its inlet end continues its grade at the slope of its last stretch. A Best Fit drain is re-fitted as before. Extending a Freeform drain clears its grade: draw it again for the longer drain.

Laterals Beyond the Cut:

When you trim a main or sub-main, the laterals (and sub-mains) that join it are checked before anything changes:

• Within 30 feet of the trimmed end: the run's outlet is moved onto the shortened main and its grade is recalculated with it. If that run is a sub-main, its own laterals stay on it at their new stations.
• Further away: the trim stops and asks first. The dialog is titled, for example, Delete 10 runs with the trim? and names them (“This trim cuts off T2-L66, T2-L67 … (they join T2 beyond the cut).”). Choose Delete them with the trim to remove those runs (and anything connected to them) along with the cut, or Cancel to leave everything exactly as it was. Only a main may stand on its own, so a cut-off run is never left loose.
• The whole trim, including the deleted runs, is one Ctrl+Z.

The Split tool divides a drainage line into two separate lines at a clicked point. This is useful when you need to assign different pipe sizes, wall types, or specifications to different sections of a run — for example, transitioning from dual-wall to single-wall at a specific station.

Where to find it: Design tab > tool rail > Split, or right-click a run > Split here

Using the Split Tool:

1. Click Split on the tool rail.
2. Move along a run: an orange dot shows exactly where it will cut.
3. Click. The run is divided into two pieces, named by the rules below.

A split never leaves a piece shorter than the Minimum lateral length in Drainage settings (20 ft unless you changed it). A click closer than that to either end is refused and a notice names the drain and the length the piece would have had, for example “Not split: T1 would leave a 6.6 ft piece toward its outlet, shorter than the 20 ft minimum run length.” Nothing changes; click further along.

Split Rules:

• Tile Main: Downstream piece stays as a main, upstream piece becomes a sub-main connected at the cut point
• Tile Sub-Main: Both pieces remain as sub-mains
• Tile Lateral: Downstream piece becomes a sub-main, upstream piece stays as a lateral connected to that new sub-main
• Surface Main: Downstream stays main, upstream becomes a tributary
• Surface Tributary: Both pieces remain as tributaries

What Happens After Splitting:

• Cut where you click: The drain is cut at the point on the line under your click. Each piece keeps the bends on its side, and the two lengths add up to the original.
• Laterals reassigned: Connected laterals upstream of the cut point are automatically reassigned to the upstream piece, with their stations measured from the cut. Laterals downstream stay on the downstream piece.
• Design parameters: Both pieces inherit the original line's depth, grade, and offset settings
• Elevation data: Fetched for both pieces and auto best-fit grade calculated
• Pipe sizes carried over: Each piece keeps the pipe specification of its own reach, and a stepped schedule is divided at the cut — re-run Auto Size Mains if the split changes what each piece carries

Important notes when using line modification tools:

• Boundary Constraints: Extended or trimmed lines may go outside your field boundary. Review and adjust as needed.
• Elevation Updates: All line modifications automatically recalculate elevation profiles and fetch new elevation data
• Connections: No edit leaves a lateral, sub-main or tributary without a run to drain into: a run cut off by the edit is moved back on if it is still within 30 feet, otherwise the tool asks first (see Only Mains Stand Alone).
• Undo and Redo: Use the curved arrows at the top left of the map or Ctrl+Z / Ctrl+Y to move through the last twenty changes. Keep backups for longer-term recovery.
• ESC to Cancel: Press ESC at any time during Extend or Trim operations to cancel before completing.

Where to find it: map dock (bottom left of the map) > Measure & annotate (the ruler) > Measure Angle

The Measure Angle tool lets you draw a line on the map and shows the bend angle at each point where it turns, with the average curvature, total deflection and length. Use it to check whether planned tile runs turn too sharply for the installation equipment, or the angle at which a lateral meets its main.

How to Use:

1. Click the ruler on the map dock and pick Measure Angle
2. Click along the path you want to check: at least three points (along the first line, the corner, along the second)
3. At each corner the bend angle is shown on the map, coloured as below
4. Double-click (or press Enter) to finish
5. The Bend Analysis box shows the sharpest bend, the average bend per vertex, total deflection, average curvature and line length; Clear measurement removes it
6. Press Esc, or start any other tool, to close the result. The same goes for Measure Distance and Measure Area; Esc part-way through a measurement cancels it.

Angle Color Coding:

• Green (<45°): Gentle bend - no issues for tile installation
• Yellow (45-90°): Moderate turn - may require special fittings or careful installation
• Red (>90°): Sharp turn - problematic for tile installation, consider redesigning the route

Summary Statistics:

• Sharpest bend: The largest single bend angle along the line
• Avg bend per vertex: Average bend angle across all vertices
• Total deflection: Sum of all bend angles (cumulative turning)
• Avg curvature: Total deflection per 100 feet of line - lower values indicate straighter runs

Where to find it: right-click a tile run > Add surface inlet here, or Design tab > tool rail > Draw > Tile > Surface Inlet

Prefer a guided walk-through with pictures? See How to: A targeted tile plan with surface inlets.

A surface inlet is a riser where surface water (a depression, a road ditch, a low spot) enters the tile. It adds a flow at one station on a tile run, and every pipe below that point has to carry it.

1. Right-click the tile run (main, sub-main or lateral) at the lowest point of the depression and choose Add surface inlet here; the menu shows the station. Or choose Draw > Tile > Surface Inlet on the tool rail and click the run: the point snaps to the nearest spot on it.
2. The inlet panel opens with the station and the grade there. Under Size the inlet from, choose:
   • Flow required — type the flow in US gal/min or L/s. The box starts on your project's unit, and the panel, the map label and the profile chart show flows in that unit whichever one you typed.
   • From its catchment — the area draining to it (acres; hectares in metric) times a drainage coefficient (in/day; mm/day in metric), worked out as you type, for example 2.0 ac × 1.0 in/day = 37.7 gpm (1 in/day over 1 acre is 18.86 gpm). The coefficient starts at 1.0 in/day (25 mm/day) — surface water, not the 3/8 to 1/2 in/day a tile system is designed for — and then at the last coefficient you used until you reload the page.
   The panel opens the way you sized the last inlet. Change any number if you know better.
3. On a lateral: click Calculate Lateral Tile Size. The lateral's own soil water and all the inlet flow on it are added up and the smallest single-wall (SW) and dual-wall (DW) pipe that carries it is offered. Pick one and click Accept. If the flow is more than the largest pipe can carry at that grade, that wall type has no size and Accept stays off until the wall you picked can carry it.
4. On a main or sub-main: click Add Inlet Flow. No pipe is picked here; run Auto Size Mains afterwards (see Tile Sizing).

Once you have run Create Drainage Layers, From its catchment fills in the area for you, and the line under it says where it came from:

• Away from a depression, the area is what drains down the nearest flow line (within about 160 ft). With no flow line near, the box starts empty and you type the area.
• In a depression (one the Depressions layer shows, or within about 50 ft of one), the flow line under the inlet is only one of the threads feeding it: water runs into a depression from every side, and an inlet in it takes the runoff of the whole depression. So the area starts on everything that drains into that low spot, counting any other low spots that overflow into it, for example 34.93 ac drains into this low spot, counting 3 other low spots that overflow into it.
• When the two differ, both are offered: The flow line here and The whole low spot, with the larger one picked. Keep The whole low spot for an inlet in a depression; pick the flow line only when the inlet takes just that one draw, or type your own area.

The inlet's map label and the report say which area it was sized from, for example 34.93 ac (low spot) at 1.0 in/day = 658.7 gpm. Expect a big pipe: an inlet taking the runoff of 35 acres needs far more than a lateral's soil water.

• A blue marker shows the inlet on the map with its flow, and the profile chart marks it with a triangle at its station (Surface Inlets in the chart legend).
• On a lateral: the size you accepted replaces the lateral's size only when it is larger; it never shrinks it. The lateral keeps its perforation (a Sock Filter lateral stays Sock Filter) and its wall type, unless you picked dual wall.
• On a main or sub-main: run Auto Size Mains with stepped sizing so every stretch below the inlet is sized for it; the inlet adds a break in the stretches.
• A main or sub-main already sized is marked out of date when an inlet above it is placed, changed or deleted (see Tile Sizing).

Managing inlets

• Change it: click the inlet marker. It opens the way it was sized; you can switch between Flow required and From its catchment. On a lateral you can also change the pipe; on a main or sub-main you change the flow only, then run Auto Size Mains. Inlets placed in older versions open on Flow required with their flow unchanged.
• Delete it: click the marker, then the red delete button.
• Inlet markers show and hide with the Drainage Design layer, and are saved in the project and its backups.
• In the PDF report, the Line-by-Line Details list every inlet with its run, station and flow; one sized from its catchment also shows the area and coefficient.
• The Drainage simulation plays each inlet: the depression filling in the rain and emptying through the inlet.

Where to find it: map toolbar (bottom left of the map) > Measure & annotate (the ruler, third button)

One floating panel holds the measuring tools and everything you can draw on the map for a printout. Annotations are saved with the project, print on the report maps, and never change the drainage design. The free viewer has the same tools, so someone you share a project with can mark it up too.

• Measure: Measure Distance, Measure Area and Measure Angle. Click points and double-click the last; the result shows beside it. These measurements are for you only and are not saved; press Esc to clear one.
• Text: Label (a line of text), Text Box (a boxed note that wraps) and Callout (a note with a leader line: click where the text sits, then double-click the point it points at).
• Shapes: Rectangle (click two opposite corners), Polygon (filled) and Polygon (hatched) (click round the area, double-click to finish). Hatching prints well in black and white — good for ground you will leave alone.
• Lines: Measure (a line with its length printed on it, which stays on the map), Arrow, Dimension (end ticks and the distance, as on a drawing) and Polyline (a plain line, solid, dashed or dotted).
• Map elements: Legend (rows of colour, line style and label, with + Add row), North arrow and Scale bar. These keep their corner of the screen as you pan and zoom.
• Markup: Revision cloud, a scalloped outline to flag a change or a question.

Drag the panel by its title bar to move it out of the way; it stays open while you work. Close it with the ×.

Where to find it: Measure & annotate > Shapes (Rectangle, Polygon (filled), Polygon (hatched)) or Markup > Revision cloud

When you finish drawing a rectangle, a filled or hatched polygon or a revision cloud, the Edit Annotation panel opens with two settings, so you can name the area and show its size in one step:

• Label: the name to show, for example Wet spot or Waterway
• Show acres: tick it to show the area of the shape (Show hectares when you work in metric)

The map shows the name alone, the area alone (12.4 ac), or both on two lines, in the middle of the shape. The area is the ground area, the same figure Measure Area gives for that shape, shown to 0.1 ac (to 0.01 ha under 10 ha in metric). You never type it: move a corner or the whole shape and the figure updates, and switching between US and metric units switches it between acres and hectares.

The next area you draw starts with the same label and tick you chose last, so marking several wet spots in a row takes one click each. Click Done or anywhere on the map to close the panel. The label and the area print on the report map and are saved with the project.

Where to find it: Measure & annotate > Edit Annotations / Clear All

1. Click Edit Annotations, then click an annotation on the map.
2. Drag it, or its corners, to move or reshape it.
3. In the Edit Annotation panel, change its text or label, colour, line width, style and the options that type has (for example Fill opacity on a filled polygon, Unit on a dimension, the rows of a legend).
4. Delete removes that one annotation; Done closes the panel.

Clear All removes every annotation after you confirm. Undo (Ctrl+Z or the curved arrow at the top left of the map) takes back annotation changes one at a time, in order with your drainage edits; Redo puts them back.

Annotations do not get in the way of design work: you can draw runs straight through them. To hide them all, untick Annotations in Layers > Annotations & Grid.

Where to find it: Layers > Map foundation > Grid Overlay switch

A spacing grid of white dashed lines behind your design, for drawing evenly spaced laterals by hand. Its settings show while the switch is on:

• Spacing: the distance between grid lines, 5 to 500 ft (default 40 ft).
• Angle: the grid's rotation in degrees.
• Pick: click it, then click a drain on the map. The grid takes the bearing of the segment you clicked and passes through the point you clicked — the quickest way to line it up with your laterals.
• An opacity slider sets how strong the lines are.

The grid shows only when you are zoomed in to field scale, and your settings are remembered between sessions.

Prefer a guided walk-through with pictures? See How to: Why is it doing that?

Geo-Surface Drain Pro makes every lateral, sub-main and tributary start on the run it drains into: within 30 feet of a compatible main, or nothing is drawn. That is what gives each run its name and lets the app add up the flow into each main.

How Connection Enforcement Works:

1. Choose the type: when you pick Lateral, Sub-Main or Tributary from the Draw menu (or in GPS survey), the check starts at once
2. Orange-red tip: until the pointer is near a run it can join, a tip follows it, reading:
   • "Move cursor near tile main or sub-main to start drawing" (Tile Lateral)
   • "Move cursor near existing surface drain to start drawing" (Surface Tributary)
   • "Move cursor near tile main or sub-main to start drawing" (Tile Sub-Main)
3. In range, the tip goes: within 30 feet of a compatible run the tip hides and you can click to start. Your first point snaps onto that run.
4. Out of range, nothing is drawn: a click further away is refused with a notice, for example Please start drawing within 30 feet of a tile main drain. Start on the main, where you want the tee, and click outward.

Type Compatibility Rules:

Different secondary drain types can only connect to specific main types:

Secondary Type	Can Connect To	Cannot Connect To
Tile Lateral	Tile Main OR Tile Sub-Main	Surface drains, other laterals
Tile Sub-Main	Tile Main (or another Tile Sub-Main)	Surface drains, laterals
Surface Tributary	Surface Main OR other Surface Tributaries	Tile drains

Connection Detection After Drawing:

Once you finish drawing a secondary drain, the system automatically:

1. Checks which compatible main is closest to the outlet (first point) you drew
2. Verifies the distance is within 30 feet (9.144 meters)
3. Validates type compatibility using the rules above
4. If valid connection found: Assigns hierarchical ID (T1-L1, S1-TR2, etc.)
5. If there is no compatible main within 30 feet, the run cannot be started there: only a main may stand on its own
6. A new lateral, sub-main or tributary starts with Force connection ticked, so its grade ties into its main (below)

The 30-Foot Rule:

Why 30 feet?

• Prevents False Connections: Lines that pass near each other without actually connecting won't be incorrectly linked
• Enforces Intentional Design: You must deliberately draw lines close enough to show connection intent
• Practical Field Tolerance: 30 feet accounts for typical GPS inaccuracy and design flexibility
• Works for All Scales: Appropriate for both small fields (few acres) and large operations (hundreds of acres)

Where to find it: Design tab > Active Design (a lateral, sub-main or tributary selected) > Force connection and Connection offset; the default offset is in Drainage settings > Tile design

With Force connection ticked (the default for every new lateral, sub-main and tributary), the run's outlet is pinned to its main's design invert (the inside bottom of the pipe) and follows it when the main's grade changes. A tile run enters the main Connection offset above that invert, so the tee need not be cut at the bottom of the pipe; the default is 4 in (it shows as 0.3 ft with the units set to decimal feet), and 0 ties the two inverts level. A surface tributary starts on its main's channel bottom.

The Connection Dot

On a lateral's profile chart, the dot at the left end (Parent Connection in the legend) is where it joins its main. Black means it comes in at or above the main's pipe. Red means its outlet sits more than 1 in below the main's invert, so water would have to climb into the main; the run counts as a connection violation, and the main's own profile shows that junction in red. Tick Force connection (or lower the main) and the dot turns black.

Only mains stand alone: every lateral, sub-main and tributary has to stay connected to the run it drains into. Drawing enforces it with the 30-foot rule, and every edit keeps it: an edit that would cut a run off asks you to Delete it with the edit or Cancel. A project from an earlier version, or a design brought in from another program, can still hold an unconnected run: it opens with a list of them, each with Reconnect and Delete, and Auto Size, the PDF report and the machine exports wait until the list is empty. Full details: Only Mains Stand Alone.

Can I turn off connection enforcement?

No. Connection enforcement is mandatory for the hierarchical naming system to work. Without it, secondary drains wouldn't know which main to connect to, and flow calculations would be impossible.

Can I move a line after drawing to "break" the connection?

Moving a line never breaks its connection. Move moves a main and carries its laterals along, and slides a lateral along its own main; Vertices keeps the outlet on its parent; Reconnect hands a bank to a different main or sub-main. To give one lateral a different parent, use Reconnect laterals or delete and redraw it.

Can I use the Extend tool to connect an orphan line?

No. A lateral, sub-main or tributary extends from its inlet end only, and its connection is at its outlet end. Only a main with no parent can be extended at the outlet. To connect an unconnected run, use Reconnect in the list that opens with the project (or Reconnect laterals), or delete and redraw it so its outlet lands on the main.

Do I see markers at connection points?

On the map, the name tells you: a lateral named T1-L5 joins tile main T1. On the profile chart, the connection dot at the left end of a lateral marks its junction, black when it enters at or above the main's pipe and red when it sits too low (see Force Connection and the Connection Dot, above); a main's profile shows the junctions of its laterals. A red disc with a white cross on the map is different: it marks a tile run crossing another tile run away from its junction.

What happens if I delete a main drain that has laterals connected to it?

They go with it. The confirmation, Delete Run & Connected Runs, lists every run connected to the main before anything is deleted, and one Undo brings them all back.

Can a lateral connect to multiple mains?

No. Each secondary drain connects to exactly ONE main drain. The connection is determined by which compatible main is closest to the outlet (first point) within 30 feet.

Where to find it: Top bar > Workspace > Landforming, then Design tab > Landforming Design

Prefer a guided walk-through with pictures? See How to: Land forming: fill the lows and flats.

Landforming builds a design surface where every part of the field falls at your minimum grade to an edge you allow water to leave by, using dirt cut from the field itself. It suits flat fields where the trouble is ground too flat to shed water rather than deep holes.

1. Load the field as for any design on the Project tab: boundary, elevation, then Create Drainage Layers. Look at the depressions and Ponding after rain so you know what you are fixing.
2. Switch the workspace: open the Workspace menu at the top of the screen and choose Landforming. The Design tab opens on the Landforming Design panel. Switching back to Drainage Design loses nothing.
3. Set the basics: Minimum grade, Compaction, Outlets and Benchmarks.
4. Click Analyze field (recommend settings), then Solve design surface.
5. Read the result on the Design surface ready card, check it drains, then make the report and the machine file.

Where to find it: Design tab > Landforming Design

• Minimum grade: the slope every part of the finished field keeps towards an outlet. 0.05% falls 0.5 ft every 1,000 ft. A higher grade sheds water faster but moves more dirt.
• Compaction: extra dirt to cut because fill settles. At 20% (the default), every 1.0 yd³ of finished fill needs 1.2 yd³ of cut. Use a soil or contractor figure when you have one.
• Outlets: the field edges water may drain over; a spot only counts as drained if its water reaches one. Click Edit… beside Outlets, then click a boundary segment (about 100 ft long) to switch it between Outlet OK (green) and No outlet (red), or pick No-outlet area or Outlet-OK area and draw round a whole stretch of edge. The line beside Outlets keeps count (for example "50 of 82 edges allowed"). Click Done painting when finished. Mark roads, berms, neighbours and higher ground as No outlet. Fewer outlets usually means more dirt to move.
• Benchmarks: the fixed points the machine calibrates to. Click Edit… beside Benchmarks, click the map to drop each one, click a marker to remove it, then Done. Put them on solid ground that will not be worked, such as a field approach just outside the boundary (a benchmark outside the field is written at its existing ground). A click outside the elevation data is refused. The first one is the master (0MB), the others BM1, BM2 and so on. Place none and the export places them for you; Clear removes them all.
• Material sourcing: how fill is supplied. The default suits most fields; its (i) explains the choices. Compare earthwork, untouched area and haul before changing it.

Outlet painting and benchmarks are part of Undo: Ctrl+Z takes back one paint session or one benchmark at a time.

Advanced settings

• Max borrow cut: the deepest the high ground may be lowered to supply fill (default 12 in, up to 120 in, or tick unlimited). Keep it within your topsoil and subsoil depth. Too shallow and the design runs short of dirt or cannot drain every low.
• Topsoil strip & return: the depth of topsoil you push aside before grading and spread back afterwards; leave it at 0 if you grade without stripping. See Topsoil strip & return below.
• Smoothness: starts at 0 and is usually not needed. Turning it on moves more soil. It rounds off sharp changes in grade so the surface is easier to farm across. Each step of the slider is one more pass. Smoothing fills a little more, so after smoothing the solve balances cut and fill again: it takes the extra dirt from the same nearby high ground, and where that is not enough it brings the smoothed surface back toward the unsmoothed design just far enough, so the cut still covers the fill and its compaction just as it does with no smoothing. Each pass can disturb more ground and move more dirt, so start at 0 and add passes only where the map shows abrupt edges.
• Revert design: throws the design away. It asks first (Discard the design?); Cancel keeps it. Your outlets and benchmarks stay.

Where to find it: Design tab > Landforming Design > Analyze field (recommend settings) / Solve design surface

Analyze field (recommend settings) runs a quick trial design and writes a recommendation under Minimum grade: how deep the design needs to cut and roughly how much dirt it moves, for example "Recommended: max cut 0.92 ft · about 4,248 yd³ of dirt — click to apply". Click that line to set Max borrow cut to the recommended depth.

Then click Solve design surface. In a few seconds the cut/fill map appears and the Design surface ready card opens with a headline that says whether every part of the field drains at your minimum grade.

The Design surface ready card

• Details (cut, fill, depths): field area, cut and fill volumes (the extra cut covers compaction), grading intensity in yd³/ac, deepest cut and fill, how far the dirt is hauled, the borrow patches and how much of the field is left untouched, and the final drainage check.
• View 3D Before / After, Hide cut/fill from map (or Show cut/fill on map), Use design as active surface, Generate PDF Report, Export design….
• Try different settings: folds the results away so you can change a setting; the design stays until you click Re-solve with new settings. After changing any setting, solve again before you report or export.

The headline tells you when something is off. The common cases:

• Short of material: "Every part of the field drains, but the design is short … of usable material." Details says how much fill has nowhere on the field to come from and offers a one-click fix, Raise max cut to … & re-solve. Otherwise allow deeper cut, bring fill in from off the field, or lower Minimum grade.
• Cut depth limit not met: a section Couldn't meet all settings — see recommendations appears under Details with changes worked out for your field.
• Part of the field still does not drain (the max cut stopped the lows being lowered enough): the headline says so and suggests a deeper max cut. This surface is not depression-free.

Where to find it: Landforming Design > Advanced settings > Topsoil strip & return

Set the depth of topsoil you strip before grading (for example 0.5 ft, which is 6 in), then click Re-solve with new settings. The finished surface does not change; the work does. Details adds a line such as "strip & return 0.50 ft over 25.9 ac — 20,880 yd³ handled twice. Max total dig: 1.40 ft." The report and the machine export add a strip pass before grading and a respread pass after it, so the topsoil ends up back on top.

3D before and after

Click View 3D Before / After. The slider between Before and After blends the original ground into the design. On a flat field, raise Exag and set Contours to 6 in: at Before, small closed rings mark the lows that hold water; at After they are mostly gone and the contours run as long, even lines towards the outlet edges.

Check that it drains

Click Use design as active surface, then on the Project tab click Create Drainage Layers again, and Hide cut/fill from map. Flow lines, depressions and Ponding after rain are now worked out on the designed ground; compare them with the field as it is. While the design is active the button reads Back to original ground: click it to put today's ground back under everything. The design is kept, so you can switch back and forth.

Edited the boundary? Solve again

Changing the field boundary after solving throws the design away, because it was worked out for the old field. The results card goes, and with it Generate PDF Report and Export design…; the panel says "The field boundary changed, so the landforming design was discarded. Solve again." No-outlet marks on the edges that moved go back to Outlet OK and the Outlets line says how many, so check Outlets first. Your benchmarks stay. Click Solve design surface to get the report and the export back.

Where to find it: Design surface ready > Generate PDF Report

Type the Field name and Company / operator name, add Preparer's notes if you want a line of explanation, and optionally a Logo image (remembered for next time).

Cost estimate (optional) takes a price per yd³ moved, yd³ per hour (scraper) and a price per machine hour, in your currency (see Currency). Fill in only what you know: with only the scraper rate the report works out machine hours but prints no cost; with both pricing methods it shows both totals side by side; leave all three blank and the time and cost section is left out. These are planning estimates only.

The report opens with the field, who prepared it and the headline numbers (total cut and fill, grading intensity in yd³/ac or m³/ha, deepest cut and fill, borrow patches, field untouched) and the drainage result. The pages after carry the cut/fill map with earth moved by depth class, the earthworks summary (with the topsoil stages and hours when given), the drainage check, before and after contours, depressions and flow paths before and after, haul distances and the borrow plan.

Where to find it: Design surface ready > Export design… (a landforming design is not sent from the Deliver tab)

• Pick the file: AGD design file (recommended) suits most land-forming machine controls and includes your boundary and a calibration benchmark. Point grid (CSV) lists each point's position, existing and design height and cut/fill in your project units and opens in Excel. Point grid (TXT) is plain text in metres. AGPS survey points (AGS) and Trimble WM-Form design (.gps) — Beta are for those displays; the .gps file asks for Display units, which must match what the display in the cab is set to. Units for each file: Exporting Your Designs → Landforming Export Units.
• Construction stage (only with topsoil strip & return on): export one file per pass and run them in order: 1. Strip, 2. Subsoil grade (set below the final surface by the topsoil depth), 3. Final / respread. Name each file after its stage.
• Point spacing: how far apart the design heights are. The app picks the closest spacing the chosen file can hold and the line under it shows the recommended maximum points. Closer points follow the design more exactly but make a bigger file than some displays will open.
• Click Export… and choose where to save. A design that is not construction-ready (part of the field does not drain, the max cut is exceeded, or it is short of material) asks Export anyway? and names the reason. If the master benchmark cannot be written, the export stops and says why.

Where to find it: Deliver tab > Project Backup > Backup Project / Restore Project

Prefer a guided walk-through with pictures? See How to: Reports and sharing with your client.

A project backup is one ZIP file holding the whole project, so you can carry on later on any computer, keep dated copies, share the design, or send it with a support question. It is named after the project with your local date and time, for example North Field - Backup - 2026-09-29 1724.zip. Restoring reads what is inside, never the name, so rename it however you like.

If you keep projects in a folder on your computer instead, the same content is saved there automatically; see Project Folders. A backup ZIP is still the file to send to someone else.

• Field boundary and the full elevation surface
• Every run with its geometry, name and type, its design limits (target, minimum and maximum depth, minimum grade), and its grade line exactly as you left it — Best Fit, Guided or Freeform — with any violations already flagged
• Pipe sizes, wall and perforation types, and each step of a stepped main
• Connections between mains and everything feeding them
• Analysis layers: flow lines, wetness index, depressions, ponding and drainage basins, if created
• Reference layers with their placement and opacity, annotations, culverts and surface inlets
• View settings: which layers were on, display units, drain colouring, and contours at the same interval
• Design and flow settings: surface-drain bottom width, side slope and ramp, tile overburden settings, and the flow and culvert settings. A project from an earlier version, which did not save these, opens with the standard values: 8 ft bottom, 6:1 side slopes, a 2% ramp, 25-year storm, 100% effective area, local road
• The ground it was designed on: raw elevation, the surface with drains carved in, a landforming design or an RTK survey ground — whichever was selected when you saved
• The report's Other items (each project keeps its own list; see PDF Reports)

Where to find it: Deliver tab > Project Backup > Backup Project

1. Click Backup Project
2. A save dialog opens straight away with the name filled in: the project's name, the word Backup and your local date and time (Geo-Surface - Backup - … when no project is open; a migrated project uses its new name, such as North Field v3.3 - Backup - …)
3. Choose where it goes. The backup is built and written there, which takes a few seconds on a large project, and a message at the bottom right says where it went

Close the save dialog without choosing and nothing is written. See Exporting Your Designs for how every export saves.

Where to find it: Deliver tab > Project Backup > Restore Project (with a projects folder: Projects dialog > Restore backup ZIP…)

1. Click Restore Project and choose the backup ZIP
2. If you have unsaved work open, you are asked to confirm before it is replaced; you can cancel
3. Progress messages show each part being restored; a large project takes roughly 10–30 seconds

Each run's saved grade comes back as it was. A run that reaches past the edge of the elevation surface uses the ground profile saved with it, so it does not trigger a fresh elevation download every time the project opens. Connections are checked and any violations marked.

With a projects folder open

If a project from your projects folder is open, the backup opens as a new project in that folder. The open project is saved and closed first, and nothing in it changes. In the Projects dialog, Restore backup ZIP… does the same.

A project from another region

A backup remembers its region. Open a project made in another region (for example a US project while the app is set to Canada) and a Region Switch Required box offers to switch to that region (for example Switch to USA): the app switches, reloads and opens the project. Cancel Import leaves everything as it was. A very large backup cannot be carried across the reload; the app says so, and you switch region yourself with the region button at the top of the window, then restore again. The demo opens projects from its own demo area only.

A damaged file is refused, not half-opened

A backup is checked as it is read, including the elevation file and the boundary. If part of it is missing or does not make sense — an empty file, a run record that is not a run, a reference layer the project names but does not contain — the app stops and names the part that did not read, before anything on your map is touched. On a file somebody sent you, ask for a fresh backup; on one of your own, open the copy in your projects folder or an earlier backup.

A backup made by a newer version than the one you are running cannot be opened; update the app and try again.

A project saved before 3.2 opens with a choice: Open as saved (the default) or Migrate to 3.3. Cancel leaves your current work alone.

Open as saved loads every run, grade, name, size and setting as you left it. Each run keeps the profile points it was saved with and the ground under them, so its depths and earthwork are the ones you designed. Nothing is re-solved and no grade is invented: a run saved without a grade (every surface drain in a 2.x project) stays ungraded until you design it or migrate.

A few figures are worked out differently in 3.2. A run's length is now measured through its bends and on the WGS84 ellipsoid (true ground distance), a lateral's maximum depth no longer counts the main's depth where it joins, and the connecting depth is read exactly where the lateral joins. An east–west run grows by up to 0.3 %, a north–south run changes by about 0.1 % or less, and every grade point, pipe size change, inlet and junction stays where it was drawn. When a project opens as saved, a notice lists once every figure that now reads differently, run by run, with the old and new value and the reason, for example T1 length 1,175.9 → 1,182.6 ft (now measured through its bends). The same summary stays under Opened as saved in the Project tab. Your design itself is unchanged.

Settings an older backup did not save, such as the overburden cut and the surface-drain cross-section, use the default of the version that saved it (a 2.x surface drain has vertical sides), for that project only; your own saved defaults are not changed. Some 2.x runs were drawn from their upper end; Open as saved keeps them as drawn, Best Fit refuses such a run and names it, and Migrate turns it outlet-first.

Migrate to 3.3 brings a copy of the project up to 3.3. Tile runs designed with Best Fit are re-solved, mains before the runs joined to them; hand-drawn Guided and Freeform grades and surface-drain grades are kept. Every pipe size is kept: Migrate never re-sizes a pipe or moves a size change. A main whose grade the re-solve changed shows ↻ on its label (hover: Pipe sized before its grade was re-solved for 3.3.); run Auto Size on it when you are ready. The settings the project was using are written into the copy, so no figure changes because of a setting. A survey ground built by an older version is kept and flagged: import the points again so it passes through every shot. Migrate never deletes or reconnects a run by itself.

When it finishes, a migration report lists every run: its length before and after, whether and how much its grade changed, whether its size is kept or needs Auto Size, and anything that could not be migrated, with the reason. Copy as text puts it on the clipboard; it is saved with the project and opens again from Migration report in the Project tab.

Both choices give existing connections a 0 in connection offset where none was saved; adjust it per run or in Drainage settings. With a project folder open, migrating creates a new project named <name> v3.3 and leaves the original untouched; from a backup file, the original ZIP is untouched and the next backup is suggested as <name> v3.3. See What's New for the rest of the changes.

Where to find it: Deliver tab > Project Backup > Backup Project; your client opens it in the free Geo-Surface Viewer > Project tab > Restore Design Project

1. Save a backup and send the ZIP by email or a file-sharing link
2. A colleague with Geo-Surface Drain Pro opens it with Restore Project and can edit everything
3. A client or crew without it opens the free Geo-Surface Viewer in a web browser, clicks Restore Design Project at the top of the Project tab and picks the ZIP. The design opens as you saved it, on the same map

In the Viewer they can pick any run and read its profile with depth, grade and pipe size, turn layers and contours on and off, open the 3D view, measure, and mark up the map with the annotation tools. On a tablet in the cab, the GPS button shows where they are on the design. Anything that changes the design — drawing or editing runs, Best Fit, Auto Size, settings, exports, reports and backups — is marked Pro and locked, so the Viewer cannot save a changed backup: ask for a screenshot of their notes. Your own copy is never changed by anything they do.

Backups work the same on Windows, Mac or Linux in a supported browser, so you can start in the office and carry on on a laptop in the field.

Where to find it: Deliver tab

Prefer a guided walk-through with pictures? See How to: Send it to the machine.

Everything that leaves the app starts on the Deliver tab. Each section is one header row; click a header to open it, and the section that was open closes. From top to bottom:

• Send the design to the machine (BETA): files for a display or machine control, and plain GIS & CAD files — see Machine delivery below
• Project Backup: Backup Project and Restore Project — see Project Backup & Restore
• Project Folder Storage: keep projects in a folder on your computer — see Project Folders
• Professional Reports: Generate Report — see PDF Reports
• Quick Exports: Save Snapshot and Export PDF Map
• Overburden guidance: the cuts ahead of the plow as Shapefile, DXF or KMZ
• Analysis Data: Export Flow → KML and Import Flow ← KML
• Raw Data: Download LiDAR and Export surface (AGS)

A land forming design goes out from its own panel on the Design tab — see Landforming Export Units below.

When an export stops and asks

• Runs not connected to a main: every design export, the report and Auto Size refuse to run and name the loose runs. Reconnect or delete them, then export again.
• Pipe sizes out of date: a machine or GIS file that carries pipe sizes first shows Some pipe sizes are out of date, naming each main and why. Export anyway writes the sizes as they are; Cancel lets you run Auto Size again first.
• Runs outside their depth limits: an installable machine file (the Autoslope package, the Intellislope tile plan, XYZP design lines) first says how many runs are designed deeper than their maximum depth or shallower than their minimum, and names the worst of them, with the depth, the station and the limit (for example T1-L2: 52.0" deep at 3+40 (max 48.0")). The limits are your own design settings, so nothing is refused: Export anyway writes the file as designed; Cancel writes nothing, so you can change the run first.

Where to find it: Deliver tab > Send the design to the machine (the first section)

Machine delivery is marked BETA: check every machine file on the display before you install from it. Have a sample file from a system we do not cover yet? Send it through the Support panel.

1. Open Send the design to the machine and pick the display or machine control in Equipment brand: Trimble WM-Drain, Ag Leader Intellislope, Ditch Assist, SD Drain Tile, Ditch Drain Pro, AGPS Pipe Pro / Pipe-FM, or GIS & CAD files for plain Shapefile, KML, DXF and KMZ.
2. Read the line under the list. It says what the design is built on: Built on government LiDAR — no RTK survey applied, Built on uploaded elevation data, or Built on the applied RTK survey (after you replace the LiDAR with your own survey on the Project tab — see Elevation Data).
3. The card lists only the files your pick can load. Click Export now, or Prepare export for files that open their own view first.

Reference only or Installable

• Reference only files show the plan on the display so the operator can find each run. The machine surveys the ground itself and installs to its own grade.
• Installable files carry design heights the machine installs to, so those heights must match what its GPS measures.

The coloured pill is the advice for this design. On LiDAR or uploaded elevation, the first reference file is Recommended, other reference files are Available, and installable files are Not recommended here. Apply an RTK survey and the installable files become Recommended. GIS & CAD files are Available on any design basis.

An installable file that is Not recommended here is still there, but its button stays greyed out until you tick the box under it, which says in plain words what you accept (for example that the design was not built on an RTK survey taken in the field, so installed depths and grades may not match the ground). The reference files need no tick.

Prepare export, and files that cannot be written

Prepare export opens the file's own view before anything is written: type the Field name the display will list, read the numbered steps for loading it, tick the box that says what the file is and is not, then click the export button at the bottom. ← All … options takes you back to the list.

When a file cannot carry your design, its card says so in red before you try and names the runs. Nothing is written; pick a reference file instead.

Mains whose pipe steps down in size. The machine takes one pipe size per run, so a main that steps down along its length (from Auto Size with stepped sizing) goes into the Trimble Autoslope package and the Intellislope tile plan as one run, its whole length, at its outlet size — the pipe at the outlet end, the largest on that main. The export view lists each one before you export, for example T1: exported as one run at its outlet size, 10 in. The stepped sizes are still in the PDF report and the shapefile export, for ordering pipe and for the record.

What each brand can take

Brand notes

• Trimble WM-Drain: copy the AgGPS folder from the ZIP to the display's USB stick; the field appears under Client Geo-Surface, Farm Projects. The field reference setup puts tile runs on the screen as lines (LineFeature). Surface drains go as one drained area instead (AreaFeature): every surface main and tributary widened 5 m (16 ft) each side and merged where they meet, so the screen shows the strip of ground each drain works without a line for every run. A surface plan, or a plan with both, gets the same package. The steering guidance (Swaths) covers every run, tile and surface, so auto steer can follow any of them; the export view says how many of each will be written. The display needs simple run names, so the runs are written as L1, L2 and so on, and the export view lists each run beside its new name. The Autoslope package installs surface drains from the file as well as tile runs, with the same master benchmark setup: each surface main goes in as a main and each tributary as a sub-main joined to its main, carrying the drain's own minimum, maximum and target depth, minimum slope and outlet depth, and no pipe size. The distance from the outlet to the target depth is the drain's outlet transition distance, or 0 when it has none. The export view says how many tile runs and surface drains it will write. A main whose pipe steps down in size goes in as one run at its outlet size, and the export view lists it. A package exported from Geo-Surface can be opened again with Import an existing design on the Project tab; its surface drains come back as tile runs, because the file does not mark a run as a ditch. None of the Trimble files carries a .prj: the display does not need one.
• Ag Leader Intellislope: Intellislope has no benchmark, so an installable plan only makes sense when the display was surveyed on the same RTK base, at the same base position, as the survey the design was built on. The plan carries each run's settings (minimum grade, minimum, maximum and target depth), not the designed grade: Intellislope solves its own grade from those settings and the ground it surveys, so installed outlet and junction depths can differ from your design. The export view and the Run settings PDF list each run's designed outlet depth and, for a run that joins a parent, the parent, the station and the parent pipe's depth there. Export stops, naming the run, if a run leaves the elevation surface.
• Ditch Assist: the map image is the recommended way — copy its ZIP to the tablet as it is and load it through Manage Layers (Ditch Assist 1.5 or later; steps below), survey the runs in Ditch Assist and install from its own grade. The XYZP design lines are the advanced alternative.
• SD Drain Tile: unzip the guidance shapefiles, copy the field folder to the USB stick and pick the shapefile on the display's Guidance tab; each run is then listed separately. The lines carry the run name, type, length and pipe size but no elevations, depths or grades. Each line runs from the top of the run down to the outlet; if one reads the wrong way, use the display's Reverse Line button.
• AGPS Pipe Pro / Pipe-FM: the guidance shapefiles are the driving lines the plow steers on, and the design bitmap is the design reference shown behind them. When you export the shapefiles, choose one file for the whole design, laterals and mains apart, or one file per pipe size. On the display: Menu → Plot Menu → Background Drawing → Load Background Drawing → Build from ESRI/Arc ShapeFiles (keep the .shp, .shx and .dbf in one folder), then turn Show Background Drawing on. The DXF background drawing asks for the job's units (see DXF).
• Ditch Drain Pro: the BMP + world file is the format this display documents, but we have not yet verified it on the display ourselves. Check the first field carefully.

Where to find it: Deliver tab > Send the design to the machine > Ditch Assist (Georeferenced map image), or SD Drain Tile, Ditch Drain Pro or AGPS Pipe Pro / Pipe-FM (Map image / Design bitmap)

A georeferenced map picture is an image of the design plus a world file: a small text file that tells the display exactly where the picture sits on the ground. It captures the visible map layers (imagery, elevation colours, boundary, drains and their labels, overlays) but never the zoom buttons, pop-ups or tooltips. Set up the map the way you want it before you export.

• JPG + JGW (Ditch Assist): first it asks Name this map; the open project's name is filled in. Type a name the operator will recognise and confirm.
• BMP + BPW (SD Drain Tile, Ditch Drain Pro, AGPS): one dialog asks for the map name and the UTM zone and hemisphere, both detected from the map. The picture is redrawn north-up in UTM metres, and the world file carries the EPSG code on its last line, as AGPS reads it.

Both come as one ZIP named after your map. Ditch Assist 1.5 or later loads the ZIP as it is (steps below). For the other displays, and for an older Ditch Assist, extract the ZIP and copy the picture and its world file together (onto the display's USB stick, or into the same folder on the tablet), side by side under the same name, or the picture will not line up.

Loading the map image in Ditch Assist

1. Copy the ZIP to the Ditch Assist tablet as it is; there is no need to unzip it
2. In Ditch Assist, open Manage Layers and choose ADD > Image File
3. Pick the ZIP to add the map to the screen
4. Survey each run in Ditch Assist and install from its own grade

Ditch Assist older than 1.5: extract the ZIP, copy both files to the same folder on the tablet, and in step 3 select both the .jpg and the .jgw (long-press each).

Where to find it: Deliver tab > Send the design to the machine > Ditch Assist > XYZP design lines — advanced

One ZIP with one tab-delimited file per run, named after the run (for example T1-L2_XYZP_Design.txt): latitude, longitude, existing ground and design height in metres, where the design height is the pipe invert (or the ditch bottom). Load each file in Slope-IQ as a designed line.

Ditch Assist installs to these heights. Without an RTK survey the file is Not recommended here and asks you to tick that you will calibrate the Ditch Assist GPS height to the same reference the design uses before installing.

Where to find it: Deliver tab > Send the design to the machine > Equipment brand > GIS & CAD files

Plain files not tied to one display, all Reference only and Available on any design basis. They carry where the runs go, not grades to install to.

Shapefile

One ZIP holding the runs as a WGS84 shapefile (.shp, .shx, .dbf, .prj) for GIS programs and the many displays that read shapefiles. Export now first asks whether to Include 3D lines: tick it and the ZIP also holds drainage_lines_3d, the same runs as 3D lines whose height is the design pipe invert (or ditch bottom) at every point and whose measure is the station from the outlet. A run with no design grade is left out of the 3D layer.

Each run carries the same figures as the PDF report: name, type, length, stations, target, minimum and maximum depth, minimum grade, pipe size, wall and perforation, outlet and inlet elevation, invert and depth at both ends, the run it joins and where, drained width and area, drainage coefficient, design flow and capacity used, whether the size is out of date, surface inlets, surface-drain earthwork, tile overburden and violation counts. Units are in the column names and follow your unit system (tgt_dep_in and out_el_ft, or tgt_dep_mm and out_el_m); length_ft and length_m are always both written. A stepped main is one line per pipe size.

KML

The runs as flat 2D lines labelled with their names, for Google Earth, online map viewers and GIS. No depths or heights.

DXF

Two drawings in the UTM zone of your field, in AutoCAD R12 format that every CAD program opens: the design (drains as 3D lines at their design grade, labels with name and pipe size, the boundary and surface inlets) and the existing ground (the same routes at ground level, written when the drains carry ground elevations). A stepped main is drawn as one piece per pipe size.

Export now asks Which units and coordinate system should the DXF use? First the units: US survey feet, International feet or Metres. Coordinates and heights are written in those units, so match the job or program that receives the file; a metre drawing loaded into a feet job comes out 3.28 times too small. US drawings and AGPS jobs are usually in US survey feet; ask whoever receives it if unsure. Your last choice is remembered; until you choose, the app starts on metres when you work in metric and on US survey feet otherwise. Cancel writes nothing. You can also bring a DXF in as a reference layer — see Reference Layers.

The same dialog also asks for the coordinate system: the UTM zone of your field (the default); in a region with a national grid, such as the United Kingdom, the Netherlands or Denmark, the national grid, for example British National Grid or RD New; in the US the State Plane zone of your field and in Canada the MTM zone (metres and feet versions); and any other system you find by typing its EPSG code or name in the search box. Picking a system defined in US survey feet sets the units to US survey feet. A drawing in any of these says so inside the file and in its name (for example drainage_design_epsg3435.dxf), your choice is remembered for that region, and when you bring the file back in as a reference layer it is read in the system it names.

KMZ map package

A picture of the current map view as a georeferenced overlay, zipped with its KML, for Google Earth and similar viewers. It is a picture, not lines: for the runs themselves use KML or Shapefile.

Where to find it: Deliver tab > Quick Exports

• Save Snapshot saves a high-resolution JPG of the map as you see it, for a presentation or an email. It is not georeferenced; for a picture a display or GIS can place, use the map images under Machine delivery or the KMZ map package.
• Export PDF Map saves the current map view as a PDF page: landscape on a desktop, portrait on a tablet.

Zoom to the area and turn on only the layers you want before you click. For a full design report with a plan at a true scale, use PDF Reports.

Where to find it: Deliver tab > Overburden guidance; the setting is in Drainage settings > Tile design; the map layer is Overburden cuts in Map Layers

A cut is a continuous stretch of a tile run that needs digging out before the plow can install the pipe at its designed grade. The cut floor follows the pipe grade, raised by the run's Max Depth (the plow limit); cut depth is the ground above that floor. An open end is still deep at the outlet, inlet or end of the grade; its label keeps the real depth.

Allowable overburden before a cut (Drainage settings > Tile design) defaults to 0, so the plow limit is respected exactly. It is a trigger: a stretch whose deepest excess is at or below it is tolerated; once the deepest excess is over it, the whole stretch is cut back to the plow limit. It never lowers the cut floor. Overburden width and side slope set the volume.

Turn on Overburden cuts to see the orange dashed cut routes. Each cut has one label at its deepest point, such as OB 43.8"; a cut shorter than 30 ft shows OB alone, and one under 2" deep is unlabelled. Zoom right in and the depth appears every 20 ft along the cut. The PDF report's maps show the dashed line without labels; its overburden table gives the depths.

The section's summary names the runs, total cut length and deepest cut, and a second line names runs it skipped (surface drains, runs without a grade, Max Depth or profile). Tick one or more formats and click Export; each file asks where to save, and cancelling stops the rest:

• Shapefile ZIP: WGS84 cut lines and depth points. Attributes use feet for stations and elevations, inches for depths and cubic yards for volumes, whatever your display units.
• DXF: 3D cut floors and depth labels in the local UTM zone. You are asked once for the units (metres, US survey feet or international feet), as for the design DXF.
• KMZ: cut routes and depth placemarks for Google Earth, each with stations, length, maximum and average depth, volume and open-end information.

Give the crew a tablet: turn the layer on, save a project backup and open it in the free Geo-Surface Viewer on a phone or tablet with the GPS dot on, to see where they are beside the cuts. Viewing the layer is free; exporting guidance is in Geo-Surface Drain Pro and the demo.

Where to find it: Deliver tab > Analysis Data

Export Flow → KML saves the flow lines from Create Drainage Layers as a KML, coloured as on the map, for Google Earth, GIS, or Ditch Assist as a layer to see where water runs while you work. With no flow lines created there is nothing to export.

Import Flow ← KML brings a flow KML you exported back in, for example on another computer, without running the analysis again. A file with missing geometry or bad coordinates is refused, naming the first bad feature, and your current flow layers stay as they were.

Where to find it: Deliver tab > Raw Data

Download LiDAR

Saves the elevation surface you have loaded as a GeoTIFF at the same resolution and extent, for CAD, GIS or engineering software. It is in EPSG:3857 (Web Mercator); reproject it in QGIS or ArcGIS if you need UTM or State Plane. The button works once elevation is loaded — downloaded, uploaded or built from a survey.

Export surface (AGS) and the land forming round trip

AGS is a plain CSV of elevation points (latitude, longitude, elevation in metres, identifier) that land-forming design software reads and writes. Export surface (AGS) writes your current surface, clipped to the boundary and sampled on a grid to stay under the format's 30,000-point limit. If a designer or design program asks for AGS, this is the file to send.

1. Load the field's elevation and click Export surface (AGS)
2. Design the land forming from that file in your land forming software, or send it to your designer
3. Bring the finished design surface back with Import AGS surface on the Project tab, under Other elevation sources. The surface is built in your browser and becomes your elevation
4. Design the tile or surface drainage on the formed ground, and install the forming first

Where to find it: Design tab > Landforming Design > Design surface ready > Export design…

A land forming design goes to the machine from its own panel, not the Deliver tab; the steps, construction stages and point spacing are in Landforming. The units written depend on the file:

Where to find it: Deliver tab > Professional Reports > Generate Report

Prefer a guided walk-through with pictures? See How to: Reports and sharing with your client.

The PDF report is for the grower, landowner or contractor you give it to, who may never open Geo-Surface. Everything printed in it describes this field and this design; nothing in it refers to the app's screens, so it reads on its own. A Detailed report contains, in order:

• Cover: your logo, the project details you typed and a map of the whole design
• Design plan: the whole field on one page with its legend, a north arrow, a scale bar and the scale in words
• Plan pages, when you choose them: one large-format plan page (the same plan on a bigger sheet), or a plan set (an index sheet and numbered plan sheets that meet at match lines, laterals labelled with their length, mains with size, length and grade)
• Before / after maps of depressions and flow, when you tick them and the analysis still matches the design
• System Summary: the estimated project cost (when you entered prices), field area, area drained, runs, lengths, pipe by size, and Drainage Coverage
• Soil Information for the field
• Tile Drainage System: Material Requirements with the cost lines, Main Line Analysis with a profile of each main, and Lateral Statistics
• Surface Drainage System: Surface Drain Details and earthwork, for surface drains
• Tile Overburden Summary, when any tile needs digging ahead of the plow
• Design Parameters, the Appendix: Line-by-Line Details, Design Exceptions (runs with a violation) and the liability notice, always last

Where to find it: Deliver tab > Professional Reports > Generate Report

Before you start

Finish the design first: runs graded, mains sized with Auto Size, no violations left. A run not connected to a main stops the report and is named; reconnect or delete it. Runs with a violation are listed under Design Exceptions.

Steps

1. Open Professional Reports and click Generate Report. The Generate Design Report dialog opens: one scrolling form with Project Information, Template & Summary Table, Report Sections, Company Branding (Optional) and Cost Estimates (Optional)
2. Fill in Project Information. Everything else starts from sensible settings and remembers your last choices
3. Click Generate PDF Report. A save dialog opens straight away with the file named, for example North Field - Drainage report - 2026-09-29 1731.pdf; with a projects folder on it starts in the project's exports folder
4. Click Save. The report is built after that (a few seconds; longer on a big field), and one message at the bottom right says where it went. Close the save dialog without choosing and nothing is written

Project Information

Project Name, Location, Owner/Client and Prepared by (Company / Operator) print on the cover. The Project Name also goes on the Design plan page and into the file name; with a project folder open it starts as the project's name. Write them the way the reader knows the field.

Template & Summary Table

• Template: Detailed (multi-page) is the full report a crew works from. One-Page Summary (landscape) is one landscape page: the map, the project details and system totals, and the summary table with as many rows as fit (a note says how many runs it shows). Custom (choose sections) shows a Sections (drag to reorder) list: tick the parts you want and drag them into order. Unticking Full disclaimer prints the short liability notice instead; the notice is always last
• Paper: Letter, Legal, Tabloid (11 x 17), A4 or A3, in every region. Every page of the report prints on it except the plan pages; the map pages and the One-Page Summary turn it landscape when that suits them. It starts on Letter in the United States and Canada and on A4 everywhere else, and the paper you pick is remembered for your region
• Plan pages: None, One large-format plan page (the same plan as the Design plan, on a bigger sheet at a finer scale) or Plan set: an index and plan sheets (see Plan set below). Both print after the Design plan on the paper chosen under them: Tabloid (11 x 17) or A3 to start with, or Legal, Letter, A4, Arch D (24 x 36 in) or A1. The rest of the report stays on the report paper. None until you choose; the choice and the paper are remembered for your region
• Summary table: tick the Columns the run table shows (Length, Min depth, Max depth, Avg depth, Min grade, Max grade, Avg grade, Pipe size, Drained ac). Per-line-type treatment sets, for each kind of run, itemize (one row per run) or average (one row for all of them) — with 164 laterals, average keeps them to one line while the mains are listed one by one

Report Sections

Untick what the reader does not need: Map Overview (snapshot of current view), Material Requirements Summary, Main Line Analysis (flow calculations), Flow Calculations & Safety Factors (the flow row and limiting-reach lines under each main), Earthwork Estimates (surface drainage), Line-by-Line Details (appendix) (also the one-row-per-lateral list) and Soil Information. Depression Maps — Before / After and Flow Maps — Before / After add one landscape page each. A landowner may want the map and the cost without the appendix; a contractor wants it all. With the Custom template the Sections list is the one list: the ticks it repeats are hidden here, and what is left is headed Also include.

Company Branding (Optional)

• Upload Logo: PNG or JPG up to 2 MB, wide rather than tall (about 3:1). It prints at the top right of the first page
• Include standard Geo-Surface disclaimer is ticked by default. Custom Disclaimer adds your own notice in your own words. Untick the standard one to use only yours; a short liability acknowledgment still prints

Logo and notice are remembered for your next reports, on every project.

Cost Estimates (Optional)

• Tile Pricing (per pipe type): one row for each pipe type in the design: size, wall type and perforation, for example 4" SW sock, 4" SW regular and 8" DW non-perforated. Enter Material and Installation per foot (per metre in metric) for each, so sock or narrow-slot pipe is priced at what it costs. A pipe type with no price reads not priced in the report. Prices you entered in an earlier version, per size and wall type with a sock or narrow-slot extra, fill these rows the first time they appear
• Connection Cost (per lateral): the tee and hook-up for each lateral
• Misc/Fittings (%): a share of the materials total for couplers, caps and fittings
• Excavation (per yd³, or per m³ in metric): prices the earth dug for surface drains and for tile overburden

Set a value to 0 to leave it out. Leave every price empty and the report prints no cost at all. Your prices are remembered for the next report.

Currency

Where to find it: Drainage settings > Currency

Every price is entered and printed in your region's currency: US dollars in the United States, Canadian dollars in Canada, pounds in the United Kingdom, euros in France, the Netherlands, Belgium, Germany, Finland and Estonia, and the local currency in New Zealand, Australia, Denmark, Norway, the Czech Republic and Switzerland. The labels in the report dialog show it, for example Material (£/m) or Connection Cost (DKK/lateral). International starts on US dollars.

• To use another currency, pick it in Drainage settings > Currency. The choice is kept in this browser for your region; pick the region default again to go back
• Amounts print with English number grouping: $1,234.50, £1,234.50, €1,234.50, and a letter code for the other currencies, DKK 1,234.50. Outside the United States and Canada a dollar names its country (US$, CA$), except the local dollar in New Zealand and Australia
• Prices are kept per currency: pound prices are never read as dollars. Nothing is ever converted from one currency to another

Other items

Where to find it: Generate Design Report > Cost Estimates (Optional) > Other items > + Add item

For costs that are not pipe, such as a road crossing, outlet riprap or mobilization. Click + Add item and fill in a Description, the Qty and the Unit price (in your currency); the Amount works itself out, and the × removes a line.

• Each line prints on its own row in the Materials table, just above the Project total, showing how it was worked out (for example Outlet riprap (2 × $450.00))
• It is added to the one project total — the same figure as the Estimated project cost on the System Summary. Misc/Fittings is not applied to it
• A line without a quantity and a price is left out; one with no description prints as “Other item”
• Other items are saved with the project (and in its backup), so each field keeps its own list, unlike the pipe prices, which follow you from project to project
• They are saved with their currency. A project whose items were priced in another currency shows them in that currency with a note, and the report lists them below the Materials table, apart from the total, without converting them. Price them in … instead keeps the numbers and counts them in your currency

System Summary and Drainage Coverage

• The Estimated project cost in large type, first, when prices were entered, with a line saying what it covers and a note naming the figures you entered for this report. If part of the design has no price, the figure carries an asterisk and a note lists each unpriced item with its quantity, such as * Not priced: 8" dual-wall pipe (1,000 ft). With no prices at all the line is left off
• Field area and estimated area drained, the number of runs of each kind and their total length, tile drainage density per drained acre and surface drain density per field acre, and the pipe length by size
• Drainage Coverage: the ground inside the boundary that lies within the drained width of a tile run, split by soil drainage class where a soil survey map covers the field (the US soil survey, or in Canada the provincial survey or the national soil landscape map), with the largest areas outside every drained width and their mean ground elevation. Without a soil map it gives the drained area for all ground inside the boundary instead of splitting it by soil

Area drained adds up each run's own drained strip once: half the distance to the run beside it on each side, and 25 ft on a side with nothing beside it. Lateral Spacing in Design Parameters is something else: the centre-to-centre spacing as drawn; one value when every spacing agrees within a foot, otherwise the range and the most common spacing.

Design plan

The Design plan page shows the whole field on one page, over the aerial photo, with the elevation legend, the pipe sizes and map symbols, a north arrow and a black-and-white scale bar (metres outside the US and Canada; feet in the US and Canada, with a metres bar too when the app is set to metric). It prints at a round scale stated in words, for example Scale 1" = 230 ft (1:2,760) on Letter paper, printed at 100 % or Scale 1 cm = 43 m (1:4,300) on A4 paper, printed at 100 %; print at 100 % (actual size, not “fit to page”) and distances measured on the paper are true. The large-format plan page is the same plan drawn again for its bigger sheet, with its own scale.

Plan set

Choose Plan set: an index and plan sheets under Plan pages for a set of drawings a contractor can work from, laid out like an engineering plan set. It is drawn from the design itself, as black linework on white, so it prints sharp at any size and every run name in it can be searched in the PDF.

• One true scale for the whole set: the largest engineering scale at which the laterals print at least 1/4 in (6 mm) apart, for example 1" = 200 ft for laterals 50 ft apart (1 cm = 25 m in metric). Print at 100 % and the scale bar measures true
• Sheet 1, the index: the whole design with the area of each plan sheet outlined and numbered, the mains named, and a sheet list saying which mains and how many laterals each sheet holds
• The plan sheets: the design cut into equal parts that meet exactly, numbered row by row from the north-west. Each sheet centres its own part; where it meets the next sheet a heavy MATCH LINE - SEE SHEET n marks the join, and the neighbouring design beyond it is shown in light grey. A part with no run on it is not printed
• Labels: each lateral shows its name and length (for example T1-L12 447'); its pipe size is added only when it differs from the sheet's usual lateral size, which the sheet's notes state (Laterals are 4" unless labelled with another size). Each main and sub-main is labelled at every change of pipe size with its size, the length of that size and its average design grade (for example T1 12" 380' @ 0.25%), with a tick where the size changes. Mains show stations every 500 ft (every 100 m in metric) from the outlet and the outlet itself. A label that does not fit on its run sits in a box close by, with a short leader; where even that has no room, the run is named only and listed in full (size, length and grade) in a table on the same sheet, and when that table does not fit, the list continues on a Run schedule sheet at the end of the set
• Title block on the right of every sheet: Prepared by, the project, Owner/Client and Location as typed in the report options, a key map with the sheet shaded, the legend, notes, north arrow and scale, and the sheet number. The line-by-line table in the appendix gains a Sheet column naming the sheet(s) each run is on

Tabloid (11 x 17) or A3 suits most fields; Letter works but gives more, busier sheets, and Arch D (24 x 36 in) often fits a field on a single sheet.

Materials and the cost lines

Material Requirements lists the pipe by size, wall type (SW single-wall, DW dual-wall) and perforation, with length and, when priced, material, installation and subtotal, each row at the price of its own pipe type. Pipe with a size but no recorded wall or perforation is priced at your drainage defaults, and a note says how much. Under the table come the cost lines, each showing how it was worked out: Pipe and installation total, Lateral connections, Misc/Fittings, Earthwork, excavation (surface drains plus tile overburden), one row per other item, and the Project total — the same figure as the System Summary.

Main Line Analysis

Each tile main and sub-main gets a row with its pipe (a stepped main reads from outlet to inlet, such as Stepped 12" to 4"), the drainage coefficient it was sized with (not sized if it never was), the delivered coefficient, land, inlet and design flow, and the capacity, % used and Adequate (Yes / NO) of its limiting reach — the stretch of one pipe at one grade with the least room over the flow it carries. A second row gives length, area, the limiting reach's grade (with the main's lowest and highest grade), depth and stations, and a line names the limiting reach and every overloaded stretch. A main with an adverse, flat or ungraded stretch shows not available. A profile chart of each main follows, and a stepped main gets a table of its segments.

Capacity uses the same calculation as Auto Size: Manning's full-pipe flow for each stretch at its own grade, with roughness by wall type and size (single-wall n = 0.015 up to 8", 0.017 for 10"–12", 0.020 above; dual-wall n = 0.012), against all the land and every surface inlet at or above it. The assumptions are printed once above the table. The drainage coefficient printed in a row is the one each main was sized with in Auto Size Mains; there is none to type in the report. Design Parameters prints the project drainage coefficient every run is checked against, then the coefficient the mains were sized at, and a pipe stretch below the project drainage coefficient is starred with a note under its schedule.

Lateral Statistics

Count, total, average, shortest and longest length, average depth and grade weighted by length with their range and the number of laterals, drawn spacing, and area drained; then Laterals by Parent, one row per main or sub-main. With Line-by-Line Details ticked, every lateral follows, grouped by parent.

A surface design's report

A surface design uses the same dialog and templates. Instead of pipe and flow it prints Surface Drain Details (each ditch's length, average depth, average grade and volume of soil to move) and the earthwork in cubic yards, worked from each drain's depth, bottom width and side slope in Drainage settings, priced at your Excavation ($/yd³) when you give one. Each surface main gets a profile.

Tile Overburden Summary

Printed when any tile run needs digging ahead of the plow: total length and volume, and each run's cuts, with the overburden width, side slope and allowance behind them. See Overburden guidance.

Soil Information

In the US and Canada: the soil survey map units under the field (in Canada with each soil's agricultural capability class), their conductivity, and the suggested spacing, depth and drainage coefficient. Where only a modelled soil is available: one soil summary for the field (texture, a modelled conductivity and, in Canada, the agricultural capability class). Soil is printed only when it was gathered for this boundary; a report made before it arrives, or while the soil service cannot be reached, leaves the section out.

Before / after maps

Depression and flow comparison pages are included only while the saved analysis still matches the ground and the design. Change either after running the analysis and the pages are left out, with one line in the System Summary saying so. Pages that are included carry the date their analysis ran.

Appendix, Design Exceptions and the notice

The Appendix: Line-by-Line Details lists every run: type, length, elevations, target and actual depths, grades, pipe, what it joins and where, area and flow for mains, and violations, then a Surface inlets list with each inlet's run, station and design flow. Design Exceptions lists the runs with a violation and where. The liability notice names the elevation the design was built on (the LiDAR project and cell size, an uploaded file or an RTK survey) and states a vertical accuracy only where the source publishes one.

The 3D Terrain Viewer turns your field into an interactive model you can spin, tilt and fly around — coloured by elevation, with shaded relief, and with your drainage design rendered as real geometry rather than lines painted on top. It opens in seconds, works offline once your elevation data is loaded, and is often the fastest way to see whether a design makes sense.

What You Can Do In It:

• Explore the terrain from any angle, coloured low-to-high in your elevation colours, with shaded relief
• Switch the surface between elevation colours and a drape of the map view you had on screen
• See your drainage in true geometry — tile mains and laterals as pipes at their designed depth, open ditches as excavated trenches, surface drains as graded ribbons
• Exaggerate the vertical scale from 1× up to 100× so gentle slopes become obvious
• Fade the ground back so below-grade pipes show through — or turn the terrain off and see the design on its own, coloured by pipe size as on the map
• Cut your designed surface drains into the terrain and see the reshaped ground
• Generate contours at whatever interval you choose, right in the 3D view
• Export the view as a PDF, or the terrain itself as a 3D model file

What you need: elevation data loaded for your field. That's it.

Where to find it: the 3D View button at the bottom right of the map; for a landforming design, also View 3D Before / After in the Landforming panel

1. Load elevation data — downloaded, from your own GeoTIFF, or built from survey points
2. The 3D View button appears at the bottom right of the map as soon as elevation data is available (and disappears again if you clear it)
3. Click it and the 3D Terrain Viewer opens over the map
4. The first open takes a few seconds while the terrain is built; after that it's quick
5. Click Close (top right) to come back to the 2D map

Navigate the 3D view using standard orbit controls:

Mouse Controls:

• Left-click and drag: Rotate camera around the terrain (orbit view)
• Right-click and drag: Pan view
• Mouse wheel: Zoom in/out

The same reminder is printed along the top of the viewer: Orbit: Left-drag · Pan: Right-drag · Zoom: Scroll. On a touch screen, the Gestures button explains the touch controls: one-finger drag orbits, two-finger drag pans, pinch zooms.

Home puts the camera back to a view that frames the whole field, edge to edge, at the exaggeration you have set. Use it whenever you lose your bearings.

Everything sits in a single toolbar across the top of the viewer.

Surface — choose what the ground is coloured by:

• Elev: elevation colours, in the colour ramp you chose for the map
• Map: drapes the map view you had on screen — satellite imagery, analysis overlays and all — over the 3D ground

Exag — vertical exaggeration, 1× to 100× (in steps of 0.5× up to 10×, 1× up to 20×, then 5×), default 10×:

• 1×: true scale — honest, but a flat field looks flat
• 10× (default): the sweet spot for most agricultural ground — gentle slopes become clearly readable
• 20× and above: for very flat fields, or when you want to make a subtle drainage pattern obvious to someone else

Only the relief is stretched, not the absolute elevation, so the field never looks like it's floating.

Opacity — how solid the ground is, from 10% to 100%, default 67%. At 67% the ground is see-through enough that pipes and trenches below grade stay visible; slide it up to 100% for solid ground.

Toggles:

• Terrain: on by default. Untick it to hide the ground, its grid and any contours so only your design shows; the field boundary is then drawn as a thin line at ground level so you can still tell where the design sits in the field. The viewer remembers the choice until you reload the page
• Drains: on by default — your drainage design in true geometry, in the same colours as the map: each pipe size in its colour (including any colours you picked yourself), each step of a stepped main in its own size colour, and an unsized tile run in dark grey. The small key next to the toggle lists the sizes shown
• Wire: on by default — overlays the terrain grid
• Burn: cuts your designed surface drains into the terrain so you see the reshaped ground rather than ribbons laid on top. Tile drains aren't burned — they stay as pipes below the surface
• Design and the Before ↔ After slider: if you've produced a landforming design, these switch the ground to the design surface and let you slide smoothly between existing and finished grade

Contours — pick an interval (6 in, 1, 2, 5 or 10 ft; 25 cm to 5 m in metric) and contour lines are generated on whichever surface you're currently looking at. Choose Off to clear them.

Export — two options:

• PDF Screenshot: captures the current 3D view into a PDF, noting the vertical exaggeration used so nobody misreads the slopes
• STL 3D Model: exports the terrain as a 3D model file for CAD software or 3D printing

Terrain Colors:

The 3D view uses the same colour ramp you chose for HD Elevation on the map (see Terrain Visualization); with the default Spectral ramp, purple and blue are the lowest ground and yellow the highest. The colours are relative to your own field: the lowest colour is the lowest point in the field, not sea level.

Shaded Relief:

The terrain is lit as though the sun were in the north-west. Slopes facing the light look brighter, slopes facing away look darker — the same convention used on topographic maps, and it makes subtle features far easier to pick out.

Clipped to Your Field:

The ground is cut to your field boundary, the same as the 2D map, so only your field is shown.

Your Drainage:

Drains are rendered as the objects they actually are, at the depth you designed them: tile mains and laterals as pipes running below the surface, open ditches as excavated trenches, and surface drains as graded ribbons across the ground. Terrain opacity defaults to about two thirds (67%): solid enough to read the ground, still see-through enough to show the pipes beneath it. Slide it down to see the pipes more clearly, or up for solid ground.

Each pipe rests on its invert, the grade line you designed, so its centre sits half a pipe diameter above it. A lateral therefore meets its main where the real tee is: a 4-inch lateral tied 4 inches up a 12-inch main enters it halfway up, at any exaggeration. Pipes are drawn thicker than life so they stay visible; the exaggeration stretches heights, not pipe thickness.

Current Limitations:

• Not every map layer appears in 3D: the analysis overlays, survey points, annotations and reference images stay on the 2D map. You can still see them in 3D indirectly by setting Surface to Map, which drapes your 2D view over the terrain.
• No GPS position in 3D: your live location is shown on the 2D map only.
• No measuring in 3D: use the measure tools on the 2D map.
• Very large fields are simplified: the ground is smoothed slightly on very large areas to keep the view responsive, so fine detail is best judged on the 2D map or in the profile chart.

Design Validation:

• Verify drainage lines follow natural terrain flow patterns
• Identify potential grade conflicts visible from 3D perspective
• Spot routing issues that may not be obvious in 2D profile view
• Confirm outlet locations make sense given overall field topography

Client Communication:

• Non-technical clients easily understand 3D terrain views
• Visual demonstration of field topography and drainage patterns
• Intuitive explanation of why certain drain routes were chosen
• Professional presentation tool for proposals and project reviews

Installation Planning:

• Visualize equipment access routes across terrain
• Identify steep areas that may require special handling
• Plan staging areas and material delivery logistics
• Understand field topography before arriving on site

Problem Identification:

• Spot drainage lines running uphill (design errors)
• Identify areas where terrain slopes conflict with planned grades
• Visualize potential ponding areas and low spots
• Verify outlet elevations relative to surrounding terrain

Problem: the 3D View button isn't there

Cause: No elevation data is loaded — the button only appears when there is terrain to show.

Solution:

• Set your field boundary on the Project tab
• Click Download elevation for this field, or import your own GeoTIFF or survey points
• Wait for the elevation colours to appear on the map
• The 3D View button appears on the map as soon as they do

Problem: the 3D view opens but never finishes loading

Solution:

• Close the view, reload the app, and try again
• Make sure your graphics drivers are up to date
• Close other tabs and heavy applications to free up memory
• Try the other supported browser — Chrome and Edge sometimes behave differently on the same machine

Problem: the terrain looks distorted, patchy, or won't load

Cause: Partial LiDAR coverage — the elevation data has gaps inside your boundary.

Solution:

• Check 2D map to verify elevation data covers entire field boundary
• Look for areas showing NoData (may appear as gaps or unusual colors)
• Redraw boundary to stay within LiDAR coverage area
• If using your own GeoTIFF, verify it covers the whole field without gaps
• Check that your elevation file uses the standard no-data value (-9999) for any gaps

Problem: Terrain appears completely flat in 3D view

Cause: The exaggeration is set too low for the ground you're looking at — or the field really is that flat.

Solution:

• Push the Exag slider up to 20× or beyond
• A field with only a foot or two of fall across it needs heavy exaggeration before anything shows
• Check the elevation data actually loaded — you should see elevation colours on the 2D map

Problem: I can't see my drains in the 3D view

Solution:

• Check the Drains toggle is ticked in the viewer toolbar
• Tile drains sit below the surface — turn Opacity down so you can see through the ground to them
• Go back to the Design tab and draw some drains if there aren't any yet
• Orbit the camera — pipes can hide behind a rise from certain angles

Problem: 3D view performance is slow or choppy

Cause: A large field, modest graphics hardware, or other tabs competing for resources.

Solution:

• Close other browser tabs to free memory
• Turn off Wire if you have it on
• Turn off Contours and Burn while you're just navigating
• A machine with a dedicated graphics card handles large fields much more smoothly

Prefer a guided walk-through with pictures? See How to: Why is it doing that?.

When the app marks something, refuses something or asks first, it is telling you about your design. Find what you see below: what it means, then what to do.

Marks on the map, the profile and the hover

A red S or D on a run

Means: S marks pipe shallower than the run's Min depth, D marks pipe deeper than its Max depth, one letter at the worst point of each stretch (small s marks repeat along a long shallow stretch). The run's name gets a warning sign, and the profile chart shows red crosses at the same points. An OB label beside a D gives the extra depth (overburden). Do: loosen the run's depth limits, move or shorten it off the high ground, or accept the deep stretch. See Depth Violations.

"Violations" count and the red count under Grade design

Means: Violations under Find a run counts the runs with a problem; the arrows beside the warning sign step from one to the next. The red count under Grade design is the number of points on the selected run that break a limit; a green "no violations" means the run is clean. Do: before you deliver, click Violations and work down the list until it reads 0.

A red dot where a lateral joins its main

Means: the dot at the left end of a lateral's profile (Parent Connection) is where it joins its main. Black means it comes in at or above the main's pipe; red means its outlet sits more than 1 in below it, so water would have to climb into the main. The run's name on the map gets a cross. Do: tick Force connection on the lateral (it sets the outlet just above the main's pipe, by the Connection offset), or lower the main. See Connection Validation.

A lateral copy "within 10 ft of a tee - check it"

Means: after Offsets or Respace, the notice names each copy that joins its main within 10 ft of another run's tee, or of the main's outlet or inlet end, for example "T1-L12 joins T1 at 1,240 ft, 6 ft from T1-SM1 - check it." The copy was laid anyway. Do: click Show in the notice, look at the junction, and move or delete the copy if two tees would sit too close for the installer.

A circular arrow (↻) after a main's name: size out of date

Means: the pipe size was worked out for a different load than the main carries now (a lateral was added, moved or deleted after sizing). Out of date under Find a run counts these runs, the run list says "size out of date" and the hover says why, for example "Pipe sized for 43.18 ac; the drawn design drains 43.14 ac." Do: finish the layout, then run Auto Size Mains again in the Tile Sizing card on the Design tab; the arrows clear. See Tile Sizing.

Max DC in the hover

Means: on a sized main, the last two hover lines are the flow it is designed to carry at the outlet and Max DC: the most water, in inches a day off its drained area, the pipe as sized can carry, with the project's target coefficient in brackets (and the coefficient the main was sized at, when that differs). At or above that value is what you want; shown in red it is below. A lateral shows its own Max DC for information only. "Max DC not available (grade)" means the run has no usable grade yet. Do: for a main in red, run Auto Size again or choose a larger pipe.

Panels, refusals and questions

"Runs not connected to a main" panel (Reconnect / Delete)

Means: only a main may stand on its own; every lateral, sub-main and tributary must end on the run it drains into. An edit in the app never leaves one loose, so this panel turns up when you open a project saved by an older version or a design brought in from another program. It names each run and how far it ends from its main. Do: click Reconnect to bring its outlet end back onto the main, or Delete if it is not wanted. Until the list is empty, Auto Size, the PDF report and the machine exports will not run.

Auto Size (or the report, or an export) refuses to run

Means: a run is not connected to a main: "Auto Size cannot run while 1 run is not connected to a main: T1-L5. Reconnect or delete it in the list, then try again." The PDF report and the design exports say the same, because a size or a file worked out with a loose lateral would be wrong. Do: fix the runs in the panel above, then try again.

"Unapplied changes", or Apply refuses a value

Means: typing a new value into a run's panel changes nothing yet. The Unapplied changes box at the foot of the panel names the run and waits. An impossible value is refused with the field named, for example "Min depth (…) is greater than max depth (…). Nothing was changed."; an unusual one asks first. Do: click Apply changes and the run is graded again; one Undo reverses an Apply. Fix a refused value and apply again.

"Apply to existing runs?" changed my runs

Means: Drainage settings are the starting values for new runs; saving them changes no run already drawn. Apply to existing does: it asks first, names what you changed and how many runs it reaches, and re-fits their depths and grades. Do: click Cancel, or press Undo once after applying and every run goes back. To change one run only, select it and change its panel instead. See Design Parameters.

Greyed-out buttons

Means: the Project tab works in order, and a step stays grey until the one before it is done: Download elevation for this field waits for a boundary, and Create Drainage Layers waits for elevation (the line under each says what is missing). On the Design tab, Draw only offers a lateral once there is a main to tie it to. Do: boundary first, then elevation, then the layers, then the main.

"Turn GPS off to edit."

Means: while GPS is on, the app is for looking, not changing: editing items in the right-click menu and the editing controls in the sidebar are locked, so a bump on a tablet in the field cannot move a run. You can still select runs, read profiles and export. Do: click the crosshair on the map dock again to turn GPS off.

"Delete runs with the trim?" (Delete / Cancel)

Means: a trim across a main would leave every run joined beyond the cut with nothing to drain into, so the app names them and asks, for example "Delete 10 runs with the trim?". Move, Reconnect and Respace ask the same way. Do: Cancel changes nothing. Deleting cuts the main back and removes those runs; one Undo puts everything back. To keep the laterals, trim beyond the last one.

"Please start drawing within 30 feet of a tile main drain."

Means: a lateral has to start on the run it drains into, so Draw > Lateral only takes a first click within 30 ft of a tile main or sub-main (it then snaps onto it). Do: click on the main where you want the tee and draw outward; if there is no main yet, draw the main first.

"… overlaps drained ground"

Means: a lateral you draw by hand is kept as drawn, but if it runs through ground another lateral already drains, the app says so, for example "T2-L113 overlaps drained ground · 50 ft spacing". Do: click Show to see the run it overlaps; Undo it if it was a slip, keep it if you mean to drain that strip twice. The layout tools stop their copies short of drained ground while Keep out of drained ground is ticked.

"For a main, choose a number of copies" (Copy offset on a main)

Where to find it: the Copy offset panel, with a main selected

Means: Copy offset copies a main whole, as new mains beside it, a number of copies to one side or both. Fill to end of main and To break line describe laterals along a main, so with a main selected the panel says "For a main, choose a number of copies (Fill to end and To break line are for laterals)." and Create does nothing. Do: choose # Offsets and type how many copies you want on each side (up to 50). Laterals, sub-mains and tributaries take all three choices. See Laying Out Laterals.

Change type refused ("Cannot reassign main drains", "Cannot promote to main", "Cannot demote to lateral")

Where to find it: Design tab > Active Design > Type > Change type

Means: changing a run's type must never leave another run with nothing to drain into, so:

• "Cannot reassign main drains — would orphan connected lines": a main keeps its type, because the runs on it would lose their outlet.
• "Cannot promote to main — mains must be standalone": a lateral, sub-main or tributary ends on its parent, and a main cannot.
• "Cannot demote to lateral — 3 line(s) connected to this sub-main": a sub-main with laterals on it stays a sub-main.
• "Cannot change between tile and surface systems" or "Cannot change between surface and tile systems": a tile run cannot become a surface drain, or the other way round.
• "Line has no parent connection": the run is not joined to a main, so it has no type to change to yet.

Do: delete or move the runs on a sub-main first if it really should be a lateral; to turn a run into a main or into a surface drain, delete it and draw it again with the type you want. See Drainage Hierarchy.

"Aligned lateral not drawn"

Where to find it: tool rail > Aligned (Aligned lateral)

Means: drawn that way, the new lateral would be shorter than the Minimum lateral length (Drainage settings > Tile design > Layout Tools, 20 ft unless you change it), so it is not drawn. Either "Aligned lateral not drawn: this way, the run enters ground already drained by" another lateral almost at once, or "Aligned lateral not drawn: this way, the run would cross" another run close to the main, and stopping 10 ft short of it leaves too little. Do: start the lateral somewhere else on the main, or turn off Keep out of drained ground in the banner to overlap drained ground on purpose. See Laying Out Laterals.

Respace refused ("The selected laterals must all be on one main or sub-main")

Where to find it: tool rail > Respace

Means: Respace evens out one bank of laterals, so it refuses a selection that is not one bank: laterals on different mains ("must all be on one main or sub-main"), mixed types ("The selected laterals must all be the same drain type."), runs that are not side by side ("must be parallel runs in order along the main"), or laterals that leave the main on both sides (it offers each side that has two or more). When the new spacing would remove a run that others are joined to, it asks first ("Respacing removes …"); Cancel changes nothing. Do: select two or more parallel laterals on one side of one main and respace again.

"Move and remove runs?" or "That move would remove …"

Where to find it: tool rail > Move (or right-click a run > Move)

Means: moving a main or sub-main re-cuts the laterals on it. When some of them would no longer fit, the app names each one and why, for example "Moving T1 40 ft NE removes T1-L3 — it would be shorter than the minimum run" (or "no longer reaches the parent"), and asks before removing them. A move that would remove too many of its laterals at once, or leave the run itself shorter than a lateral needs ("That move would leave T1 only 12 ft long"), is refused. Do: Cancel changes nothing; move it a shorter distance, or redraw the run. One Undo reverses a move.

"Clear grade", and "Replace Best-Fit Grade?"

Where to find it: Design tab > Active Design > Grade design > Clear

Means: Clear (its tooltip reads Clear grade) removes the selected run's grade line, its depths and its violations; the run stays drawn with no grade, and is listed in black until it gets one. Choosing another grade method on a graded run asks first, for example "Switching to Guided will replace the existing Best-Fit grade." Do: Keep Existing Grade changes nothing; after replacing, one Undo puts the old grade back. See Grade Analysis.

Projects and saving

"Your current work has never been saved"

Where to find it: appears when you open an empty project from the project list

Means: what is on the map now is not in any project, nothing of it is on disk, and opening the empty project clears it (boundary, elevation, analysis and reference layers and every run). Do: click Save it as a new project first to keep it, then open the other project. Discard my work, open the empty project cannot be undone. Cancel changes nothing.

"The project save did not finish — it may have written part of the project"

Means: a save to your projects folder did not complete in time (a busy or disconnected drive, a cloud folder that stalled). Part of the project may have been written. Your work is still on the map. Do: export a backup ZIP at once (Deliver > Project Backup > Backup Project) so you have a complete copy, then check the drive or folder. See Your Projects Folder.

"This project is already open in another tab or window"

Means: a project can be open in only one place at a time, so two tabs never save over each other. Do: close it in the other tab or window first, then open it here.

"Reload without a project?" ("No project folder is active — anything unsaved will be lost")

Where to find it: top bar > Save & switch project (circular arrows), with no project open

Means: with a project open, this button saves it and then returns to the project list. With no project open there is nothing to save to, so the work on the map would be lost by the reload. Do: Cancel, then create a project for the work (or export a backup ZIP) before switching.

"This project was designed on the RTK survey ground …, which could not be restored"

Means: the project was designed on an RTK survey you imported as the ground, and the survey surface could not be rebuilt when it opened (the message gives the reason). It has opened on the LiDAR ground instead, so depths and grades are now measured from LiDAR, not from your survey. Do: import the survey again as the ground (Project tab > Other elevation sources) before you rely on any depth, grade or export. See Elevation Data.

"… legacy stepped-main schedule(s) could not be rebuilt safely"

Means: a project from an older version carried step-down pipe sizes on a main that could not be carried over safely to how sizes are kept now. Do: before construction or export, run Auto Size Mains again in the Tile Sizing card on the Design tab and review the segments of each main with stepped sizes. See Tile Sizing.

Exports and files

An export asks first ("Some pipe sizes are out of date", "Export anyway?")

Means: the file would carry something you may not want. Out-of-date sizes are listed by main with the reason; an installable machine file counts the runs outside their own depth limits and names the worst, with depth, station and limit; a landforming design that is not construction-ready asks "Export anyway?" and says why. Do: Cancel and fix it (for example run Auto Size again), or Export anyway knowingly. A run not connected to a main stops every design export until it is fixed.

"Not recommended here" on a machine file

Means: files the machine installs from (design heights and grades) are marked Not recommended when the design is built on government LiDAR rather than an RTK survey: LiDAR heights were not measured on your field and can be off by several inches. Reference files (a map or lines to follow on screen) stay Recommended. Do: to export one anyway, tick the box under it to say you understand; its export button does nothing until you do. Use an RTK survey as the ground (Project tab) and the same files become Recommended. See Exporting Your Designs.

What BETA means

Means: a BETA badge marks a part of the app that works and is in use but is new: machine delivery, DXF export and DXF import, the drainage simulation and land forming (including its Trimble WM-Form .gps export). Do: check its results against what you know before relying on them; load every machine file on the display and check it before you install from it. If your display needs a file the app does not make yet, send a sample through Help & feedback.

Where did my file go?

Means: every export asks where to save. Once the file is written, a note at the bottom right says where it went (the folder you chose, your project's exports folder, or your browser's Downloads folder on a browser without the save box), and names the file. If you close the save box with Cancel or the ×, nothing is written and no note appears. Do: export again, or search your computer for the file name in the note.

Elevation

"Government Elevation Server Not Responding"

Means: the elevation comes from government servers (USGS in the US, Natural Resources Canada in Canada), and now and then they are down. The app retries and also tries the public LiDAR archive as a backup; this box appears only when all of that fails, and nothing was loaded. Do: click Keep Trying, or Cancel for Now and come back later; outages usually clear within minutes, maintenance within a few hours. Your boundary and design are not affected.

"Coarse Elevation Data"

Means: in the US, 1 m LiDAR is read from the USGS public archive first. If the archive cannot be reached, the USGS elevation server answers instead, and its answer can be coarser than you asked for; the box says what was delivered. Do: click OK; the elevation is usable but small features may be smoothed out. Fetch again later for the 1 m LiDAR.

Which elevation am I designing on? (the Active DEM line)

Means: the Active DEM line under Create Drainage Layers names the elevation the design is built on. "1 m LiDAR" with the survey project's name is what you want. "1 m LiDAR archive not reachable — resolution not confirmed" means fetch again later. "USGS 11 m national DEM (no 1 m LiDAR published here)" means there is no 1 m LiDAR for the field yet. Do: on coarse data, check grades on the ground, or use an RTK survey as the ground. See Elevation Data.

"The USGS 1 m LiDAR archive could not be reached" or "Could not fill the gaps from the USGS elevation server"

Means: US only. The 1 m LiDAR is read from the USGS public archive first; when the archive cannot be reached during a fetch, the USGS elevation server answers instead, and its answer may be coarser (the Active DEM line then says "1 m LiDAR archive not reachable"). "Could not fill the gaps" means the archive answered but left some cells without heights, and the server could not fill them, so those cells stay empty. Do: download the elevation again once your connection is back to get the 1 m LiDAR everywhere.

"Unable to retrieve any elevation data for this line", and "Re-fetch elevations?"

Where to find it: Design tab > Active Design > the circular-arrows button beside the run list (Refresh active profile)

Means: every run reads its heights from the elevation under it. "Unable to retrieve any elevation data for this line" means no point along the run got a height: the run lies outside the elevation you downloaded, or the elevation is not loaded. Where only some points are missing, the gaps are filled from the nearest heights and marked as estimated. Refresh active profile on a run with estimated heights asks "Re-fetch elevations?"; Re-fetch reads every height along the run again from the elevation now loaded, Cancel changes nothing. Do: make sure the run lies inside the field's elevation (download elevation for the whole field if needed), then Refresh active profile.

"Warning: More than 50% of the elevation data is estimated."

Means: more than half of the points along the selected run had no height and were filled in from their neighbours, so its profile, depths and grade are mostly guesswork. It usually means the run goes off the edge of the elevation, or crosses a hole in it. Do: look at the elevation under the run (turn on HD Elevation in Map Layers); download elevation that covers it, or move the run, then click Refresh active profile and answer Re-fetch.

"This survey is … km from the field"

Means: when you use an RTK survey as the ground, the app checks where its points land. Read with the coordinate system you chose, the middle of the survey is more than 1 km from the field boundary; a wrong UTM zone is the usual cause. Do: Cancel and pick the right zone (or latitude / longitude), then import again. Use it anyway only if the survey really is somewhere else.