3 tools · Topic

TR-55 Calculators & Software

TR-55 ("Urban Hydrology for Small Watersheds") remains the reference procedure for small-watershed peak flow and detention sizing in the United States. Listed here: WinTR-55, the NRCS’s own program; HydroCAD, a commercial package built on TR-55 and TR-20; and Delta Hydro Studio, which has a browser TR-55 calculator.

Delta Hydro Studio

FreemiumVerified

Browser-based hydrology and hydraulics calculators for practising engineers — no install, report-ready output.

Urban Stormwater & InfrastructureActiveRational Method Culvert Sizing

HydroCAD

Commercial

The US land-development standard for TR-55/TR-20 hydrographs and detention pond design.

Urban Stormwater & InfrastructureActiveDetention Design TR-55

WinTR-55

Gov-Public

NRCS's official implementation of TR-55 small-watershed hydrology: peaks, hydrographs and storage.

Hydrology & Catchment AnalysisStableTR-55 SCS Curve Number