Every reading on this site traces back to a real gauge, in a real river.
Two networks of streamgages feed the live numbers you see across the site.
The U.S. Geological Survey operates thousands of streamgages nationwide. We read discharge, gauge height, and water temperature directly from the USGS Instantaneous Values API.
ColoradoSome Colorado rivers also report through the Colorado Division of Water Resources telemetry network. Those requests are proxied through our servers to keep things fast and avoid browser CORS restrictions.
CFS stands for cubic feet per second: the volume of water passing a fixed point in the river every second. A cubic foot is about the size of a basketball. One cfs is one of those, passing a fixed point, every second. A small creek might run at 20 cfs; a major western river can run well over 10,000 cfs during spring runoff.
Gauge height (or stage) is the water surface elevation at the gauge, measured in feet against a fixed reference point. It's the most direct measurement a gauge takes; discharge is calculated from it using a rating curve specific to that site.
Water temperature is measured in degrees and matters for fishing (cold-water species get stressed above certain thresholds) and for safety (cold water increases the risk of hypothermia if you end up in it).
Most gauges report new readings every 15 to 60 minutes. The values on River Flow Co reflect the most recent reading available from the source network at the time the page loads.