Runoff Calculator.
Convert rainfall into a water opportunity estimate. Search a location to auto-fill annual rainfall from open climate data, then adjust site areas and runoff coefficients. This is a planning tool; final RWH/GWR design needs site survey, soil/percolation assessment, filtration design and local compliance review.
Inputs
Highlighted fields can be edited — results update instantly.
Scenario Snapshot
Gross and net runoff estimates update instantly.
Surface Area and Runoff Coefficients
Enter actual measured areas where available. Coefficients are planning assumptions.
| Surface | Area (sqm) | Runoff coefficient | Annual runoff (L) | Event runoff (L) |
|---|
EcoLive interpretation
How to read the output.
High hard-surface runoff
Prioritize filtration, first-flush control and recharge points before the runoff becomes urban flooding or wasted drainage.
Low green/soil runoff
Protect natural infiltration; avoid over-paving and use landscape depressions, trenches or recharge beds where suitable.
Storage vs recharge
Storage is useful for reuse, but large monsoon volumes usually need distributed recharge and overflow routing.
Tool data method: this tool uses editable baseline data and planning assumptions. Values must be verified against latest IMD, municipal, CGWB and project-site records before engineering decisions.