Calculate peak runoff rates using the Rational Method for small drainage areas
Rational Method (Q = CiA)
Suitable for drainage areas less than 100 hectares. Uses rainfall intensity based on time of concentration.
hectares
minutes
Time for water to travel from farthest point to outlet
SCS Curve Number Method
Suitable for larger drainage areas. Uses soil type and land cover to compute runoff.
hectares
mm
Calculating runoff rates...
Runoff Analysis Results
Peak Runoff Rate
0 m³/s
Maximum flow rate during storm event
Total Runoff Volume
0 m³
Total volume from storm event
Runoff Coefficient
0
Computed runoff factor
Disclaimer: This calculator provides estimates for preliminary design and educational purposes. Final stormwater management design must be completed by a qualified professional engineer. Local regulations and site-specific conditions must be considered.
Your Results Will Appear Here
Select calculation method, enter parameters, and click "Calculate" to see runoff analysis.