Stormweir: Runoff Lab

About Stormweir: Runoff Lab

Stormweir: Runoff Lab is a focused, fully on-device app. Civil stormwater workbench for Rational Method runoff, NRCS curve-number screening, detention routing, orifice/weir discharge, Manning channels, and storm scenarios.

KEY FEATURES
- Rational and curve-number screens
- Editable inflow/outflow routing
- Orifice and storage metrics
- Site-photo evidence
- Editable sample data and CSV import
- Side-by-side scenario comparison
- Local PDF evidence export
- Fifty-three original offline reference plates

ONE-TIME AND PRIVATE
- One paid download; no subscription or in-app purchase
- No account, advertising, analytics, tracking, or developer-operated backend
- Core features and bundled content work offline
- Work remains on device unless you deliberately share or export it through an Apple system interface

Hydraulic estimates are planning aids and do not predict flood safety. Verify survey data, rainfall criteria, local regulations, tailwater, blockage, and professional design review.