Dust off the drift boats and rafts, the Bureau of Reclamation will increase flows from Anderson Ranch Dam on the South Fork of the Boise River June 25 from 600 cubic-feet-per-second to approximately 1,600 cfs.
The section from the dam to about 10 miles downstream is popular with anglers, and the canyon section between the Danskin boat launch and Neal Bridge is popular with whitewater boaters, who typically stay overnight in the canyon.
Drought in 2013 meant Anderson Ranch Reservoir was drawn down to less than 25 percent of capacity, but late season snow and spring rain helped to refill the reservoir.
“South Fork flows are expected to remain at these levels into August, which will also benefit river rafters and kayakers,” said Brian Sauer, Water Operations Manager. “These are typical summertime flows, starting a little later than some years due to last year’s drought.”
Increased flows will also flush sediment deposited in the canyon after mudslides hit the river in the fall of 2013, which reshaped the stream bottom. The slides occurred when heavy rains hit after intense wildfires last summer that burned vegetation throughout the river corridor.
The increased flows will not adversely impact the available water supply for the irrigation season this year, Bureau of Reclamation officials said.
Current water storage in the Boise River reservoirs is about 96 percent of capacity. Anderson Ranch Dam is about 28 miles northeast of Mountain Home, Idaho.