RainYard Tools
Drain test
Soil Infiltration Rate Calculator
Convert a simple test-hole water drop into inches per hour.
Before you calculate
Use it before choosing a rain garden, dry well, or infiltration trench.
- Repeat tests improve confidence.
- Very slow soil needs a different design.
- Do not test frozen or saturated ground.
Infiltration rate2.00 in/hrMeasured drop over elapsed time.
Average per test1.00 in/hrOnly if drops were summed across repeats.
Drain time for 6 in3.0 hrScreening estimate.
1
Pre-soak the hole if the soil is very dry.
2
Measure the water drop over time.
3
Use the rate as a planning screen.