SCS Triangular Hydrograph Calculator

Generate SCS triangular unit hydrographs for simplified runoff analysis. Calculates peak discharge, time to peak, and runoff volume per TR-55 methodology.

Input Parameters

Watershed Parameters

Basic watershed characteristics

mi²

Contributing watershed area

hours

Tc for the watershed

in

Depth of runoff to route

Advanced Parameters

Optional hydrograph parameters

hours

Duration of unit rainfall (default: Tc/5)

484 US typical, 2.08 SI typical

hours

Time step for hydrograph output

Triangular Hydrograph Relationships

  • • Recession time Tr = 1.67 × Tp
  • • Time base Tb = 2.67 × Tp
  • • Volume = 0.5 × qp × Tb
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