
Over 50 California Department of Fish and Wildlife staff conducted a successful relocation over the past two days of 6.5 million young Chinook salmon imperiled by raging, muddy flows of 65,000 cfs below Oroville Dam as a giant hole caused by erosion continues to expand.
The California Department of Water Resources boosted the water release from 40,000 cubic feet per second to 65,000 cfs with hopes that they could avoid the use of the emergency spillway at the Lake Oroville and Oroville Dam site in Butte County.
However, the agency issued an update saying they plan to reduce the releases to 55,000 cfs to prevent erosion along the north side of the spillway from compromising nearby power line towers.
"Whether the emergency spillway is used or not, Oroville Dam itself is sound and there is no imminent threat to the public," emphasized DWR Acting Director William Croyle. "We’re ready to use the emergency spillway if needed. But we’re trying to avoid it because there will be sediment and debris impacts downstream.”
Staff have relocated the 6.5 million fall-run and spring run Chinooks from the Feather River Hatchery in Oroville to the hatchery annex near the Thermalito Afterbay. These fish, approximately 1 inch long each, would die from suffocation in the turbid, sediment-laden water if left in the raceways of the hatchery.
Approximately 1.5 million juvenile salmon will remain in the hatchery where they will benefit from sediment ponds set up to cleanse the water. Engineering staff have also set up a charcoal filtration system utilizing a fire hydrant pump for the 1 million eyed steelhead eggs remaining in the hatchery.
"Right now we consider our rescue operation to be a good success," said Hughan. "We brought in staff from hatcheries all over the state to help in this emergency effort."
"We used 8 trucks to move the fish and have done everything as fast as we can," Hughan noted.
In March 2016, CDFW staff estimated that Feather River salmon