Tractor and ditcher cutting a surface drain across a field
Home·Resources·LiDAR Drainage Mapping
LiDAR Drainage Mapping

Where does water flow? Where are the depressions? Where does it pond?

LiDAR Drainage Mapping generates flow-line, ponding, and depression layers where public LiDAR is available. Prepare fields in the Ditch Assist® app for in-cab use, or use the exclusive Geo-Surface™ owner portal from the office. It is currently included for Ditch Assist owners — check and save your priority fields now while source coverage is available.

What it is

A drainage picture of the field, before you ever survey it.

Two questions get answered every time you plan drainage work. Where does the water want to go? And where does it stop along the way? The eye can't read either one from the cab. A walk through at green-up gets you closer but costs a day, and you still miss the closed depressions that dry down before they leave a visible mark.

Where public LiDAR is currently available, LiDAR Drainage Mapping answers both from a polygon you draw in the app or a boundary you draw or import in the Ditch Assist owner portal on Geo-Surface. The cloud pulls the available elevation data, runs flow-accumulation, ponding-fill, and depression-detection passes, then returns drainage layers for field planning.

In the app, generated layers save to the tablet under your survey, design, and grading workflows. In Geo-Surface, owners can map from the office and export geo-referenced images. Access and coverage depend on the current service and third-party public datasets, so build your priority-field library now while data is available.

LiDAR drainage mapping layers over a field
Ditch Assist app recording an RTK survey line across a field
Who it's for

Where LiDAR Drainage Mapping fits — and where it doesn't.

Currently included for owners, but it is a planning layer, not a survey replacement. Check that your field has coverage, then use the layers to decide where to run your RTK survey.

Best for

Planning before you survey

Seeing flow, ponding, and depression patterns before you commit a route — for ditching, tiling, land forming, or leveling — from the tablet in the field or the office on Geo-Surface.

Not for

Replacing a real survey

Certified as-built elevation or legal survey work. LiDAR Drainage Mapping is built from public LiDAR archives — drive your own RTK survey in the app when the job needs verified ground truth.

In-app workflow

Drop a polygon. Generate. Done in 30 seconds.

Tap the LiDAR & Mapping card on the Home screen, pick Prepare Field, draw the field on the in-app map, name it, and hit Run Selected. Up to 800 acres per fetch — split a bigger field into adjacent boundaries.

STEP 01

Draw the boundary

Tap the map to drop corners around the field. Undo removes the last point, Clear starts over. Three corners and the Prepare Field button activates. Drop more for a tight polygon along an irregular boundary.

STEP 02

Generate

Tap Prepare Field, name the field, keep Generate flow and depression mapping ticked, tap Run Selected, wait roughly thirty seconds. The app fetches LiDAR, picks an appropriate resolution for the polygon size, ships it to the processor, pulls back the finished layers — all from the tablet.

STEP 03

Use the layers

The Flow Routes, Ponding Risk, and Depressions layers appear on the map and save on the tablet. Tap Done and open the mode you're working in — the layers stay under your survey, design, and grading screens.

Ditch Assist owner portal

Run the same drainage mapping from the office on Geo-Surface.

Ditch Assist owners currently receive complimentary access to an exclusive drainage mapping portal on Geo-Surface.com. Geo-Surface is an independent venture created by Simon Knutson — co-founder of Northern Plains Drainage Systems (NPDS) and creator of Ditch Assist. That shared origin makes this planning portal available to Ditch Assist owners at no additional cost today.

Check coverage and build a field library

Locate each field, draw or import its boundary, and fetch the best public LiDAR available for that location.

Inspect and tune drainage layers

Read elevations, compare ponding and true depressions, adjust ponding sensitivity, and show major or minor flow paths.

Plan the survey and export

Use the map to focus the first RTK survey, then export a Ditch Assist image and matching world file as a geo-referenced overlay.

What the Geo-Surface portal walkthrough covers

This walkthrough shows the complete office-planning workflow available to Ditch Assist owners through the complimentary Geo-Surface portal. The app shown is the legacy version; the current app can now generate LiDAR drainage layers directly after owner hardware has been connected.

  • 1. Check LiDAR coverage Review coverage across Canada and the United States before creating a field.
  • 2. Create the field boundary Find the field, draw its boundary on the map or import an existing shapefile, and repeat for as many fields as needed.
  • 3. Fetch and inspect elevation data Geo-Surface downloads the highest-resolution public LiDAR available and lets you click within the field to inspect ground elevations.
  • 4. Generate the drainage map Create field-specific flow paths, predicted ponding, and true-depression layers on demand at higher resolution than the earlier owner portal.
  • 5. Tune the analysis Adjust ponding sensitivity and the drainage-area threshold to focus on the wettest problem areas, major drainage routes, or smaller flow paths.
  • 6. Plan the first RTK survey Use the layers to identify priority problem areas and likely survey routes before collecting ground-truth elevations with Ditch Assist.
  • 7. Export to Ditch Assist Choose Map Outputs, select Ditch Assist Image, and export the JPEG plus matching world file as a geo-referenced map overlay.
  • 8. Use the current app or the portal The current Ditch Assist app now generates these LiDAR drainage layers directly once owner hardware has been connected. Geo-Surface remains valuable for advance planning, boundary imports, elevation inspection, multi-field organization, and overlay exports.
Field boundary

Draw it or import it

Start with a field boundary in the portal. Draw it directly, or import an existing boundary when the field is already mapped.

High-accuracy LiDAR

Generate drainage layers

Fetch public LiDAR, then generate flow maps, depressions, and ponding layers like the in-app workflow.

Back to Ditch Assist

Save reference layers

Export geo-referenced images from the portal and load them into the Ditch Assist app as map reference layers for field work.

My LiDAR Fields dialog with Boundary, Flow Routes, Ponding Risk and Depressions toggles, an opacity slider and a ponding cutoff slider
What comes back

Three layers. One LiDAR fetch.

Flow lines, ponding risk, depression detection. Each layer toggles independently; ponding and depression layers have their own opacity. Ponding layers also have a Cutoff slider that hides ponding shallower than the depth you set, so only the deeper spots show.

LAYER 01

Flow Routes

The channels water already wants to follow across the field. Survey along one and design the ditch on it. That line follows the natural fall, so the Slope-IQ™ Best-Fit design needs less cut and you move less material.

LAYER 02

Ponding Risk

The areas where water collects and stands, modelled by filling the low spots in the LiDAR surface. Combine with Flow Routes to see whether a single tile run drains a whole cluster, or whether multiple runs make more sense. Raise the Cutoff slider to hide the shallow puddles that don't matter.

LAYER 03

Depressions

The closed-contour low spots — places that would pond if water reached them, whether they currently show it or not. Plan a leveler pass to fill them, so the same spot doesn't drown out every wet spring.

Working with LiDAR Drainage Mapping

The drainage jobs it helps you plan and check.

LiDAR Drainage Mapping has its own card on the Home screen, but it doesn't move any dirt. You use it to decide where the ditch goes, where the tile goes, and which low spots need filling; the layers then sit under your survey, design, and grading screens. Use it in the app when you are preparing the tablet for field work, or use the Geo-Surface portal when you want to review fields and save reference layers from the office.

Surface drainage

Picking the route

Problem: A ditch designed without seeing the flow pattern can run uphill of where water actually wants to go — needs more depth, drains fewer acres.

Fix: Survey along the LiDAR Drainage Mapping Flow Route. The line already follows the natural fall, so the Slope-IQ™ Best-Fit design needs less cut, and the ditch picks up water where it already runs.

Ditching mode →

Tile planning

Where to lay the run

Problem: Tile lines placed on a satellite-photo hunch miss the depression clusters that cost yield, or trench past dry ground.

Fix: Lay the proposed run over the Ponding Risk + Depression layers. See at a glance whether one main covers the worst acres, or whether two shorter runs into a common outlet drain more for the same trench length.

Tiling mode →

Land forming

Validating the design

Problem: A 3D land-forming design looks good on a contractor's screen, but you don't know if it targets the spots that actually pond.

Fix: Before the work starts, lay the design over the LiDAR Drainage Mapping Ponding Risk layer. If the cuts and fills miss the spots that pond, ask for a redesign before any dirt moves.

Land Forming mode →

Leveling

Catching the closed lows

Problem: Closed depressions on otherwise-graded ground don't show on a satellite photo and rarely catch the eye on a walk-through.

Fix: The Depression layer pinpoints them. Plan a leveling pass that takes them out the next time the leveler's on the field — instead of finding them next spring when the crop drowns.

Leveling mode →

Site visits

Skipping the green-up walk

Problem: A walk through at green-up to find wet spots costs a day and you still miss the closed depressions that don't pond visibly.

Fix: Generate LiDAR Drainage Mapping the night before. Drive straight to the wet spots and depressions the layers mark on the tablet, and book the work without a second trip.

Validating the work

Did it actually drain?

Problem: After a tile run or a forming pass, you want to know whether the depressions you targeted have actually been resolved.

Fix: The layers you generated before the job are still on the tablet. Turn them on and walk each spot they marked — you see which ones are fixed and which still hold water.

How you unlock it

Pair the tablet. Map your priority fields now.

LiDAR Drainage Mapping unlocks when the tablet pairs with a Ditch Assist control module (Full Automation Kit or Guidance Only Kit), a Ditch Assist DIG™ Kit, or an Emlid Reach receiver licensed for Ditch Assist Lite. That connection tells the app you own the hardware. Owners can also use the Geo-Surface portal for office mapping, boundary imports, and geo-image exports. Because public coverage comes from third parties, check and save priority fields while it is available.

Once

Pair the tablet

Connect the tablet to a Ditch Assist or DIG controller, or to the GPS receiver on Ditch Assist Lite, the way you do for any grading session. The app reads the kit or receiver serial, marks you as the owner, and LiDAR Drainage Mapping is unlocked on that tablet.

Online

Generate at the yard

Switch the tablet onto yard Wi-Fi, a hotspot, or LTE in the truck. Draw boundaries around every field on the operation, generate each one, and save the layers for field use.

Office

Use Geo-Surface

Request access through the contact form, then open the owner portal on Geo-Surface.com to draw or import boundaries, generate drainage maps, save geo-referenced images, and bring those references into the app.

What it's worth

Drainage mapping in the cab and in the office.

Drainage mapping comes with your Ditch Assist kit or Ditch Assist Lite license. Owners currently get the in-app field workflow plus the Geo-Surface office portal at no additional cost, with no per-acre charge.

Built in

Not an add-on

LiDAR Drainage Mapping runs inside the same app the operator uses for survey, design, and grade — same map, same gestures, no second tablet in the cab.

Owner portal

Map from the office

The Geo-Surface owner portal lets Ditch Assist customers draw or import boundaries, generate flow, ponding, and depression layers, and export geo-referenced images before heading to the field.

Geo-Surface Pro

A path to full design

When owners need full surface design, tile design, land-forming design, the new PC version, and contractor-grade tools, the portal displays a 20% discount code for Geo-Surface Pro.

In the app

Generate now. Save on the tablet.

Fields you generate now are filed locally on the tablet. Toggle whole fields or individual layers, tune opacity, and hide shallow ponding without leaving the workflow you're running.

Saved Fields / DEMs

Your library

Open Saved Fields / DEMs from the LiDAR & Mapping sidebar — or pick My LiDAR Fields from the Map Layers dialog — and every field you've generated is there. Expand a field to toggle its Boundary, Flow Routes, Ponding Risk, and Depressions independently.

Opacity & Cutoff

Dial it in

Tap Map Layers on the map. Each ponding and depression row has an expand caret — open it for the Opacity slider. Ponding layers also expose a Cutoff slider, which hides ponding shallower than the depth you set.

Across every workflow

Always under the work

Generated layers stay on the map in any mode you open — under your survey, design, and grading screens. Same picture from survey to final pass.

Where you can use it

Public LiDAR is available now. Check each field.

LiDAR Drainage Mapping depends on third-party public archives that Ditch Assist does not control. Availability and resolution vary by location and can change. Check your priority boundaries in the app or Geo-Surface portal now, and generate the fields that are covered.

United States
USGS 3DEP currently provides broad coverage across the continental US. Source availability and resolution vary, so verify each boundary in the app or portal.
Canada
NRCan HRDEM currently covers many agricultural areas in Western Canada. Availability and resolution vary by location; check priority fields now in the app or portal.
Max area per fetch
Up to 800 acres per drawn boundary. Larger fields can be split into adjacent fetches.
Processing time
Roughly 30 seconds from tapping Run Selected to layers on the map.
Internet
Required while drawing and generating. Saved layers reload fully offline thereafter.
Full reference

Step-by-step in the operator manual.

Every dialog, slider, and storage detail — in English, Spanish, and Brazilian Portuguese. Hand it to the operator who'll be running it.

Read the manual → About the app
Tiling setup dialog in the Ditch Assist app with Saved LiDAR DEM and Open LiDAR & Mapping options
FAQ

LiDAR Drainage Mapping questions.

Layers

What are the LiDAR Drainage Mapping layers?

Flow Routes, Ponding Risk, and Depressions. Flow Routes show the channels water already wants to follow. Ponding Risk shows where water collects and stands, modelled by filling the low spots in the LiDAR surface. Depressions show closed-contour low spots that would pond even if they don't show it today.

Cost

Do I need a subscription to use LiDAR Drainage Mapping?

Currently, owner access is included at no additional cost with eligible Ditch Assist hardware or a Ditch Assist Lite license. Service and third-party public LiDAR availability apply, so check and generate priority fields while coverage is available.

App vs portal

What's the difference between the in-app workflow and the Geo-Surface owner portal?

The in-app workflow runs on the tablet: draw a boundary, tap Prepare Field and then Run Selected, and the layers save under your survey, design, and grading screens for field use. The Geo-Surface owner portal runs the same mapping from the office — draw or import boundaries, review fields ahead of time, then export geo-referenced images and load them into the Ditch Assist app as reference layers.

Unlocking it

How do I unlock LiDAR Drainage Mapping?

Pair the tablet with a Ditch Assist control module, a Ditch Assist DIG™ Kit, or an Emlid Reach receiver licensed for Ditch Assist Lite (only a GPS on the implement, no wires), the same way you would for any grading session. The app reads the kit or receiver serial, marks you as the owner, and LiDAR Drainage Mapping unlocks on that tablet. Request Geo-Surface owner portal access separately through the contact form.

Coverage

How big a field can I map, and where is it available?

Up to 800 acres per drawn boundary — split larger fields into adjacent fetches. Coverage depends on third-party public LiDAR datasets and varies by location. Check each boundary in the app or Geo-Surface portal and generate priority fields now where data is available.

Try it live

Try the Ditch Assist app in your browser.

Click through the live browser build of the Ditch Assist app — the core screens and workflows, no hardware required. LiDAR Drainage Mapping stays locked in the simulator: it unlocks once the tablet pairs with Ditch Assist hardware or a receiver licensed for Ditch Assist Lite.

Ditch Assist app home screen in the browser simulator