On Monday, the Big Wood River north of Ketchum hit its lowest-ever recorded flow for that date, the U.S. Geological Survey reported.
The previous low-flow record for June 8 was set in 1966, the USGS stated.
On Monday, a USGS gauge near the Sawtooth National Recreation Area headquarters north of Ketchum recorded a flow rate of 220 cubic feet per second. The minimum-flow record set in 1966 was 234 cfs, USGS records show.
The river’s recent low discharge can be attributed to modest snowpack this past winter, which has translated into less water available for runoff to the basin’s rivers and streams, according to USGS spokesman Tim Merrick.
Late last month, Natural Resources Conservation Service hydrologist Danny Tappa said the water supply outlook for Wood River Valley residents wasn’t looking good. The biggest concern this summer will be for users on Magic Reservoir, he said.
“Water shortages are nearly a certainty at this point,” he said. “We had a dismal fall precipitation in 2019, which didn’t help.”