With Lake Oroville rising more than 82 feet this month, the water level is now cutting into the buffer needed for flood control.
The lake began encroaching this reservation limit Saturday, according to Kevin Dossey, a senior engineer with the state Department of Water Resources. Depending on how wet conditions are in the Feather River basin, this limit may range from 848.5 feet of elevation in a very wet year to 875.5 feet if it is dry.
Lake Oroville reached 850.12 feet Saturday. As of 5 p.m. Monday, the lake level was 854.82 feet, 45.18 feet from the crest of 900 feet.
Dossey said DWR has been speaking with the U.S. Army Corps of Engineers on flood control. The corps commonly allows variances on the water level depending on upcoming precipitation and hydrology.
Last week, the corps allowed the water storage level to encroach the limit and will re-evaluate the situation this week. DWR may be permitted to continue filling the reservoir or it may need to increase releases into the Feather River.
If releases are ordered, the state agency may run additional water through the Edward Hyatt Powerplant underneath the dam or use the controlled spillway gates.
Other north state reservoirs have increased their outflows as they encroach on flood control limits. Folsom Dam began spilling water March 7. Up in the Lake Shasta complex, releases from Keswick Dam into the Sacramento River increased Friday to make room in Lake Shasta.
All three of the reservoirs are above their historical averages for March 20. Folsom is at 108 percent, Shasta is at 110 percent, while Oroville is at 109 percent. Trinity Lake west of Shasta is at 63 percent of its historical average.