Design Storm Generators

The official portal for Australian Rainfall & Runoff design inputs — losses, temporal patterns and preburst.

Storm and foul water drainage design and 1D hydraulic modelling software for UK and Irish civil engineers.

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

Browser-based rainfall frequency analysis — fit and rank 11 distributions with confidence intervals.

The US Army Corps standard for rainfall-runoff modelling — event and continuous simulation, free to use.

Neyman-Scott stochastic rainfall generation in Python — synthetic series and disaggregation, single or multi-site.

The US precipitation-frequency standard — point rainfall depths for any duration and return period, free.

CDM Smith's free rainfall statistics and STORM-method screening model — IDF analysis, disaggregation, CSO planning.

Stochastic storm transposition in Python — probabilistic extreme rainfall scenarios from remote-sensing data.

EPA's Climate Adjustment Tool for SWMM — apply downscaled climate projections to rainfall and evaporation inputs.

Dewberry's open tool for building STAC catalogs of storms and gauge data — inputs for stochastic storm transposition.

Hydrologic modeling software for urban and rural stormwater management, master drainage planning, and pond design.

The Watershed Bounded Network Model — free Australian runoff-routing hydrology for flood estimation.

Free web tool for building synthetic design-storm patterns — 560+ temporal patterns, exportable to SWMM and HMS.

Python automation for HEC-HMS — batch and parallel runs, design storms, and DSS handoff to HEC-RAS.