Oroville Dam spillway 2019

The California Department of Water Resources releases water from the Lake Oroville flood control gates down the newly-constructed main spillway for the first time since May 2017 in Butte County. Main spillway releases will continue to manage lake levels in anticipation of rain and snowmelt. Photo taken April 2, 2019. 

The Feather River was projected to drop about three feet in elevation Tuesday after the Department of Water Resources, due to dry-weather forecasts, cut back releases from Lake Oroville. Members of a local sportmen’s association have raised concerns over the state’s management of releases, saying such reductions could result in a number of negative effects downstream.

Feather River flows decreased Tuesday by roughly 5,800 cubic feet per second, dropping the river’s elevation from 49.1 feet to 46.2 feet over a 24-hour period. James Stone, president of Nor-Cal Guides and Sportmen’s Association, said that amount of decrease in elevation should not happen in such a short amount of time.

“After the town hall meetings two years ago following the Oroville spillway incident, we asked DWR that when they do drops in releases, to never do more than 2,500 cfs in a 24-hour period,” Stone said. “Anything more than that can lead to bank erosion and major stranding of salmon and steelhead outside the banks.”

Erin Mellon, assistant director of Public Affairs for DWR, said the state department goes by the U.S. Army Corps of Engineers’ manual that governs how releases are carried out.

“When river flows are high, such as it was this past Monday, we make incremental adjustments to flows – decreasing up to 5,000 cfs in 2-hour increments,” Mellon said. “When natural river flows are lower, we make these changes even more gradually to avoid wide fluctuations in river levels.”

When levees and river banks become saturated during high-water conditions, Stone said, they cannot drain quickly enough when the water elevation is decreased rapidly, often resulting in erosion. Bank erosion leads to sediment deposits into the river, further clogging things up.

On top of that, when river levels decline rapidly, juvenile salmon and other types of fish either hiding from predators or looking for food on the outskirts of a flooded area can become trapped because they aren’t given adequate time to realize that the water level is dropping, Stone said.

The solution, Stone said, is to stair-step releases by 500 cfs or so every few hours, never going over 2,500 cfs in a 24-hour period. 

“I understand there are different needs for that, like flood protection, water storage and releasing enough water out to the ocean, but the most important thing out of this is that they need to change their management strategy,” Stone said.

The Army Corps’ manual is from 1970. Mellon said one of DWR’s primary goals for long-term Oroville operations is to encourage and advocate for the Corps to update the manual “so that operations can respond to the new realities under climate change to better support the shared goals of flood protection, fishery health and water supply.”

Mike Morris, a director with Levee District 9 in the Live Oak area, said his district doesn’t foresee any impacts from Tuesday’s 3-foot drop in elevation, not like the rapid decreases of 5 feet or more overnight that occurred in the river two years ago after the spillway incident. 

“All we are asking for is that when they reduce flows to do so stair-stepping down slowly, so they don’t cause more environmental damage,” Stone said.

Fluctuation in flows on Wednesday in the Feather River at Yuba City are projected to level out, with the river’s elevation expected to hover around 45 feet into the weekend, according to the California Nevada River Forecast Center.

Recommended for you