Current uses real-time USGS stream gauge data to evaluate wading safety. Two factors are combined: flow rate (CFS) and gauge height (feet). The worst of the two determines the overall rating.

Thresholds vary by river. Rain forecast uses Open-Meteo data at each gauge's coordinates. Heavy rain in the next 48 hours typically causes flow rises within 6–24 hours depending on watershed size.

Data: USGS NWIS (flow, height, temp) + Open-Meteo (rain forecast). Updates every 15 minutes.