Sediment Monitoring | ErrorZap

Cutaway illustration of the Colorado River at Lees Ferry with a USGS streamgage station on the bank, satellite beaming its 15-minute stage readings skyward, and a labeled rating curve floating beside the channel

River Gauges: The Boxes That Watch the Colorado River

How USGS streamgages, sediment sensors, sandbar cameras, and flood alerts track the dam-controlled Colorado River.

Illustrated Colorado River cutaway shows a gage, submerged sand, survey boat, and plant plots under canyon walls.

USGS river science infrastructure in Grand Canyon

Gages, sediment samplers, sandbar surveys and plant plots measure how dam operations and tributary floods change the Colorado River.