Methodology

How RiverStat.us works.

Data Collection

RiverStat.us collects data from official public U.S. government sources including the U.S. Geological Survey (USGS), the National Weather Service (NWS) through the National Water Prediction Service (NWPS), and the Environmental Protection Agency (EPA). All source data is public domain and freely available.

Freshness

Every reading and forecast displays its observation time, ingestion time, and freshness status. Freshness categories include:

Fresh: Observed within the last 30 minutes
Delayed: Between 30 minutes and 2 hours old
Stale: More than 2 hours old
Unavailable: No observation recorded

Source Qualification

Gauge identity is source-qualified: each gauge is identified by its source (e.g., USGS) and source-native site identifier (e.g., 01646500). This preserves provenance and avoids ambiguity across data providers.

Limitations

RiverStat.us is a public information viewer. It does not provide safety assessments, navigability guidance, or rescue recommendations. Missing data is explicitly displayed as unavailable — it is never treated as normal conditions. Forecast availability varies by location and is clearly labeled when not available.

Coverage

The launch scope covers select USGS active stream gauge stations. NWPS forecast data is overlaid where reliable station crosswalks exist. Coverage scope, source filters, and indexed counts are available on the status page.