Surveying channel and berm

You survey the channel first, then the berm, both inside (or relative to) the zone.

Channel survey

1. With the zone painted, drive to where the channel should start — usually near the uphill edge of the zone at the high end.
2. Tap Start in the survey sidebar.
3. Drive the channel line through the zone. Hold roughly to the contour for level, but ease downhill toward your outlet so the channel picks up drainage fall. Watch the DROP and A→B GRADE numbers climb as you build that fall.
4. Keep an eye on the zone-position readout. If it reads OUTSIDE ZONE in red, steer back into the corridor.
5. Tap Stop at the outlet end. Name and save the channel survey.

The app records your actual driven channel line — that's what the terrace design uses, not the contour itself.

Berm survey

1. The wizard prompts for the berm. The zone and your channel line stay drawn for reference.
2. Drive to the berm centerline on the downhill side of the channel.
3. Tap Start, drive the berm line end-to-end, tap Stop.
4. Name and save the berm survey.

Why the berm goes downhill

A terrace catches water in the channel and the berm keeps it from cutting downhill across the field. So the berm sits on the downhill side. Survey it there — a berm on the wrong side gives nonsense fill volumes in the design dialog.

Loading saved surveys

If you surveyed the channel and berm earlier, you can choose Load Existing Survey in the wizard and pick them, the same as standard Terracing.