Map water flow in the owner portal

Steps 1 to 4 turn a field into a water map: where it drains, where it ponds and where the low spots are. Do them before you draw routes, because the routes follow the flow.

Before you start

• You are logged in to the portal and past the welcome window (Open the portal)
• The Country box at the top of the left panel shows your country
• You can click, drag and zoom with the mouse. New to it? Read Computer basics for the portal first.
• Optional: the field boundary as a KML, KMZ or zipped shapefile on the computer (see Upload an outline instead)

How long it takes: about 5 minutes for a quarter section.

Steps 1 to 4, click by click

Click the search box

Step 1, Find your field. The search box is the white box at the top middle of the map. It reads Search locations in USA... in grey (in Canada, Search locations in Canada...).

Click once inside it.

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Type where the field is

Type the farm's address, the nearest town, or the field's coordinates. In the picture we typed Nevada, Iowa.

Coordinates work as decimals, for example 49.177, -97.953, or as degrees, minutes and seconds. A longitude typed without a minus sign is read as west.

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Press Enter

Press the Enter key, or click the magnifying glass at the right end of the box. The map moves to the place you typed.

If you typed coordinates, a red pin marks the spot, and step 1 shows a line starting with Showing and the coordinates.

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Zoom in on your field

Point the mouse at your field and roll the mouse wheel away from you, a little at a time. Or click + at the top left corner of the map. To move the map, drag it. (Help: Move and zoom the map.)

Stop when the field fills most of the map, like this.

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Click Draw an outline

Step 2, Outline your field. In the panel down the left side, find step 2. Click its orange Draw an outline button.

A dark bar appears across the top of the map: Click each corner of your field. Click the first corner again to close the outline. Esc cancels.

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Already have the boundary as a file? Skip to Upload an outline instead.

Click the first corner

Point at one corner of your field and click once. A small blue dot marks it.

Take in all the land that drains through the route you have in mind, not just the field you farm. The LiDAR is loaded for the outline only.

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Click the other corners

Click each of the other corners in turn, going round the field. A blue line joins the dots.

Clicked in the wrong place? Click Cancel on the dark bar (or press Esc), then click Draw an outline and start again.

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Click the first corner again

After the last corner, point at the first blue dot and click it once. That closes the outline. A double-click on the last corner closes it too.

The outline turns orange-red and the map zooms to fit it.

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Check the outline

Step 2 folds down to one line with a green tick: Outline · 137.9 ac (your field's acres). The yellow line now reads Get the LiDAR for your outline.

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Click Get LiDAR

Step 3, Get LiDAR. Step 3 is now open under the folded lines. Click its orange Get LiDAR button.

A window opens in the middle of the screen called Choose elevation resolution.

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Leave Recommended picked

The window lists four levels of detail: 1 m, 2 m, 3 m and 5 m. The one that suits your outline has a green Recommended tag, and its round dot is already filled in. Leave it.

For a field up to about a section that is 1 m. A bigger outline gets a coarser recommendation, because each load is limited to 3,000 cells on its longest side (about 1.9 mi at 1 m). Coarser loads faster with less detail.

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Click Fetch

Click the blue Fetch button in the bottom right corner of the window. (Cancel closes the window without loading anything.)

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Wait for the LiDAR

A window with a turning circle shows the LiDAR coming in. Elapsed counts the seconds. A quarter section takes a few seconds; a large field a minute or two.

That is the government elevation server working, not a freeze. Leave the window alone; it closes by itself.

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Check the LiDAR loaded

The field turns to colours: purple is the low ground, yellow the high. A legend at the top right gives the heights in feet. A purple 3D View button appears at the bottom right.

Step 3 folds to LiDAR · 1 m. Click its Change to see which LiDAR project it came from, for example LiDAR · 1 m · IA NorthCentral 2020.

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Click Show water flow

Step 4, Show water flow. Step 4 is now open. Click its orange Show water flow button. There is nothing to set first.

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Wait 5 to 30 seconds

A window called Showing where water flows counts up to 100 %. The work happens on your computer. It usually takes 5 to 30 seconds.

Cancel stops it. You can run it again, or go on and draw routes.

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Read the result

Dark lines and coloured patches appear inside your outline. Step 4 folds to Flow lines, depressions, ponding and wetness, step 5 opens, and the yellow line reads Draw a route along the flow you want to drain.

• Dark lines are flow lines: where surface water runs. The thicker the line, the more land drains through it.
• Follow the thickest line to where it leaves the field. That is your outlet.
• Red, orange and yellow patches are the Ponding Predictor: red gets wet first in a big rain, then orange, then yellow.

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Next: Plan ditch and tile routes (step 5).

Upload an outline instead

Use this when you already have the field boundary as a file: a KML, a KMZ, or a zipped shapefile (all the shapefile's parts in one ZIP). It replaces the drawing steps.

1. Click Upload an outline

   In step 2 of the left panel, under Draw an outline and the word OR, is a box with a dashed edge and a cloud icon: Upload an outline. Click it.

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2. Pick the file

   Your computer's own window for opening files appears. Find the boundary file (it is often in Downloads or Documents, in the list on the left of that window). Double-click the file.

3. Check the outline

   The outline appears on the map and step 2 folds to Outline · 137.9 ac (your acres). Carry on at Click Get LiDAR.

   A file with no outline in it gives That file doesn't contain a field outline. Use a KML, KMZ or zipped shapefile.

In Canada: use a quarter as your outline

In Canada, step 1 has a Find a Canadian quarter box. It finds a quarter from your land description and can make it your outline, so you skip drawing.

1. Pick the quarter

   Click the Quarter box and pick NE, NW, SE or SW from the list.

2. Type the section, township and range

   Click in Section and type the number. Do the same for Township and Range.

3. Check the meridian

   Meridian starts on W1 (west of Principal), which is most Manitoba land. For land elsewhere, click the box and pick E1 or W2 to W6.

4. Click Find quarter

   A red square marks the quarter on the map, and a line under the button reads, for example, NW-32-2-4-W1 found. Where LiDAR exists, the map turns to grey shaded relief after a few seconds.

5. Click Use this quarter as my outline

   The square becomes your outline and step 2 folds to Outline · 162.3 ac (that quarter's acres). Carry on at Click Get LiDAR.

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Is there LiDAR for my field?

Most of the United States has detailed LiDAR; Canada has it in parts. You can check before you outline.

1. Click Show LiDAR coverage

   It's the orange button in step 1. If step 1 is folded to Field found, click its Change first to open it.

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2. Zoom out and look

   Roll the mouse wheel toward you to see your area. In the United States, places with published LiDAR are shaded orange; gaps keep the normal photo. In Canada, the map turns to grey shaded relief wherever LiDAR exists.

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3. Put the photo back

   Click the round layers button at the bottom left corner of the map. In the Map Layers panel, roll down to Base Layer, click the box and pick Satellite Imagery. Then click the ✕ at the top right of the panel to close it. (Loading LiDAR in step 3 also puts the photo back by itself.)

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Change the outline later

A new outline clears the LiDAR and the water maps, so the portal asks before it lets you draw one. Your routes stay.

1. Click Change on the Outline line

   In the left panel, click the blue word Change at the end of the line Outline · 137.9 ac. Step 2 opens again.

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2. Click Draw an outline

   Click the orange Draw an outline button in step 2 (or Upload an outline to use a file). A window asks Change the outline?

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3. Click Change the outline, or Keep it

   The window says Changing the outline clears the LiDAR and the water maps. Your routes stay.

   • Change the outline (red, bottom right): draw the new outline, then run steps 3 and 4 again.
   • Keep it (grey, to its left): leaves everything as it was.

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Read and tune the water map

What the map shows is set in the Map Layers panel. Changing it never reruns the water flow, so try settings freely.

1. Click the layers button

   It's the first of the three round buttons in the bottom left corner of the map: white, with an orange icon of stacked layers. The Map Layers panel opens above it.

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2. Tick or untick a layer

   Click the tick box in front of a layer's name to switch it on or off. The slider on the same line sets how see-through it is. Roll the mouse wheel over the panel to see the rest of it. Click ✕ at its top right corner to close it.

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What each layer shows:

• Flow Lines: Where surface water runs. Lines get thicker as more area drains through them. Controls: On/off, see-through slider (75 % to start), Show drains ≥ N ac. The slider's range follows your field, from the smallest drainage area in it up to the largest, and it starts at the low end (0 ac on most fields).
• Ponding Predictor: Where water shows first in a big rain: the bottoms of low spots first, then flat ground that a lot of the field drains onto. Red, then orange, then yellow. Controls: On/off, see-through slider, Wet last ↔ Wet first slider (move right to see only the first spots, left to see how far wet ground spreads).
• Depressions: Hollows at least 6 in deep and 0.025 ac (1,080 ft²) across, shaded by depth: under 3 in, 3–6 in, 6–12 in, over 12 in. Off to start. Controls: On/off, see-through slider, Show under 3 in.
• Wetness Index: Ground that tends to stay wet, from its slope and the area draining onto it. Off to start. Controls: On/off, see-through slider.
• Field Contours: Contour lines from the LiDAR inside your outline, labelled in feet, with a count such as 85 contours (1ft). Controls: Spacing: Off, 0.1, 0.2, 0.25 ft, 6 in, 1, 2, 5, 10, 20 ft. Lines: White / Black.
• HD Elevation / HD Hillshade: The LiDAR as colours, and as grey shaded relief. Both on to start. Controls: On/off, see-through slider; colour ramp for HD Elevation.

Set up a clean map for the tablet

The picture you save in step 6 shows exactly the layers that are switched on. A busy map is hard to read on a tablet in a moving cab. Before you save, in Map Layers:

• HD Elevation and HD Hillshade both unticked, so the satellite photo shows through. With only HD Elevation off, the field stays grey.
• Flow Lines ticked, Show drains at 5 to 10 ac (at 0 ac every small rill shows)
• Ponding Predictor ticked, slider at the start position or a little right; or Depressions instead if you are leveling or filling
• Field Contours Spacing Off, or 1 to 2 ft on flat ground (0.25 ft clutters the picture)

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The Show drains slider only changes what is drawn; the water flow is not run again. Move it as often as you like.

Look at it in 3D

1. Click 3D View

   It's the purple button in the bottom right corner of the map (it appears once the LiDAR is loaded). The 3D Terrain Viewer fills the window.

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2. Turn it with the mouse

   Drag with the left mouse button to turn the field round. Drag with the right button to slide it. Roll the wheel to zoom. Exag stretches the height (10x to start) so a few feet of fall is easy to see; Home goes back to the first view.

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3. Click Close

   The red Close button in the top right corner takes you back to the map.

If it doesn't work