Survey Contour Lines and Watershed Area
1 dayUse A-frame or laser level to mark contour; calculate catchment area above each swale.
Field context
This workflow is part of 3 niche fields
Complete guide for swale water harvesting — step-by-step workflow, tools, checklist, and expert tips to get started.
Use A-frame or laser level to mark contour; calculate catchment area above each swale.
Size swale volume to hold 25 mm rainfall event; space swales at 3–5 m vertical interval.
Dig swale trench on contour; place excavated soil on downhill berm; compact spillway.
Plant trees on berm, water-loving species in swale base; monitor infiltration after first rain.
Calculate swale trench depth and berm height for target water storage volume on contour.
Size swale and rain garden catchment area to handle design storm rainfall event.
Calculate mulch volume needed to cover swale base and berm after planting.
Estimate excavation time based on swale length and soil type.
Recommended swale sizing parameters.
| Slope % | Depth (m) | Width (m) | Spacing (m) |
|---|---|---|---|
| 3–5 | 0.3–0.5 | 0.6–1.0 | 20–30 |
| 5–10 | 0.4–0.6 | 0.8–1.2 | 15–25 |
| 10–15 | 0.5–0.8 | 1.0–1.5 | 10–20 |
Watch water flow during a heavy rain before digging — nature shows you where swales belong.
Plant the most water-hungry trees directly on the berm — they intercept infiltrating water first.
Call 811 or local utility locate service before digging — swales cross buried lines.