
The American River below Nimbus Fish Hatchery on the opening day of steelhead season, January 1, 2020. Photo by Dan Bacher.
The U.S. Bureau of Reclamation issued an order on January 10 to reduce water releases on the American River below Nimbus Dam, the crown jewel of the Sacramento Region, from 2,500 cfs to 2,000 cubic feet per second (cfs) on January 15. Yet after issuing that order, the Bureau dropped the flows even lower, down to 1800 cfs, on January 16.
The slashing of flows was made at a time when fall Chinook salmon eggs are incubating in the redds (nests), a critical period in the life cycle of the species.
Over the past 18 years, salmon runs on the American River, the crown jewel of the Sacramento area, have declined dramatically from a record run of over 150,000 fish in 2003 to relatively small numbers in the past few years. In only one year since 2005-2013 did the run exceed 50,000 fish.
Drops in river flows like this often result in the dewatering of salmon redds (nests) and the stranding of salmon fry in pools. The dropping of flows could also impact steelhead that are now spawning in the river, according to salmon advocates.
The Reclamation spokesperson cited storage conservation in Folsom Lake as the reason for reducing flows in the memo.
The January 10 memo from Reclamation states:
“Please make the following release changes to the American River at Nimbus:
Date Time From (cfs) To (cfs)
01/15/20 0100 2,500 2,400
01/15/20 0200 2,400 2,300
01/15/20 0300 2,300 2,200
01/15/20 0400 2,200 2,100