Stormwater Drainage Calculator

Calculate peak runoff using the Rational Method, size drainage pipes with Manning's equation, and estimate detention volumes. Define catchment areas with surface types for automatic runoff coefficient calculation.

ASCE Rational · EN 752 · AS/NZS 3500.3

Design Parameters

Standard

Return Period

Storm Duration (min)

Pipe Material

Pipe Gradient (%)

Rainfall Intensity (mm/hr) optional

Time of Concentration (min) optional

Catchment Areas

Name

Area (m²)

Surface Type

C (runoff)

Name

Area (m²)

Surface Type

C (runoff)