The honest fine print

About the data

Where the numbers come from

Everything on RiverDates starts at the U.S. Geological Survey, which operates thousands of stream gauges with daily-flow records reaching back decades — public domain, and the best river dataset on Earth. For each of the 229 curated gauges we pull the USGS daily-statistics record (retrieved 2026-08-07) and the ribbons you see are its percentiles: for every calendar date, where the middle of history sits (the median), the middle half of years (25th–75th), and the range most years stay inside (10th–90th). Bands are averaged across neighboring days so a single odd sensor day doesn't paint false texture.

The right now numbers never touch our servers: your browser asks the USGS live-readings service directly and pins the answer onto the chart. Live values are provisional — the USGS reviews them before they join the official record.

Why these 229 rivers

The gauge list is hand-picked, and that curation is the point. A river can have a dozen gauges; only one or two sit on the water people actually float. Every entry here names the reach its gauge represents and the put-in town it serves, across 43 states. If your river is missing, it usually means no gauge with a long, current record sits close enough to the float water to be honest about it.

The promise about safety

Flow data is not a safety rating, and this site never says a river is safe. Not "safe for families," not "safe at this level," not once. Rivers kill people who trusted a number. What the data can do is context: how today compares with the same date across decades. The judgment calls — cold water, wood in the channel, your group's skill — belong to you, your PFD, and the locals who saw the river this morning.

Independence

RiverDates is an independent project. It is not affiliated with or endorsed by the U.S. Geological Survey; USGS data is used under its public-domain terms, credited on every river page. No accounts, no tracking of you — saved rivers live in your own browser.