The expansion is a reminder of how far USGS data can travel. The independent science agency's job is to measure the nation's water and deliver reliable data to the decision makers who manage it, from water agencies to emergency managers to the National Weather Service. But that same public data is open to anyone, and increasingly, others are building on it to reach the public directly.

That is what Watch Duty does. The free app, run by a non-profit, pulls together information from many sources and delivers it straight to people's smartphones through maps, alerts, and plain-language updates.

Geoff Havens, a flooding coverage reporter for Watch Duty, tracks river conditions across the country and relies on USGS data to do it. At Watch Duty, reporters aren't traditional journalists; they monitor live conditions during an event and turn their observations into clear, timely updates for users. 

"As a Watch Duty flooding reporter, USGS data is an invaluable resource as I track current and forecast flood stages in waterways across the country, and for our users as they follow conditions in their area," says Havens. "River gage data from USGS provides our users with clarity, making local water levels clear and accessible for everyone. We're proud to play a part in bringing USGS information to families and first responders as they seek fast, clear and reliable information that helps keep them safe."

For USGS, the role is upstream and constant. The agency operates a national network of streamgages that measure water levels in real time and makes that data publicly available, around the clock, on Water Data for the Nation. USGS doesn't issue flood warnings or tell people when to evacuate; that work belongs to the National Weather Service and local emergency managers. What USGS provides is the measurement, the reliable and continuously updated record of what the water is actually doing.

The value of that data is measured in more than numbers on a gage. When a river is rising, the difference between safe and stranded can come down to how quickly people understand what the water is doing and how much time they have to act. USGS keeps that record flowing. The faster and more clearly it reaches people, the more lives it can help protect.