
The California Department of Water Resources (DWR) issued an updated statement regarding the expected failure of the auxiliary spillway at Oroville Dam in Butte County. The agency noted that Oroville Dam itself is sound and is a separate structure from the auxiliary spillway.
DWR has doubled the flow down its main spillway from 55,000 cubic feet per second (cfs) to 100,000 cfs to avert more erosion on the auxiliary spillway.
In a press conference in Oroville, Eric See, DWR public information officer, stated that the flows from the auxiliary are on the decline and the overall conditions are stable, but the situation has changed dramatically since then.
Based on information from DWR and the incident command team managing Lake Oroville, counties and cities near Lake Oroville issued evacuation orders for residents. The concern is that erosion at the head of the auxiliary spillway threatens to undermine the concrete weir and allow large, uncontrolled releases of water from Lake Oroville. Those potential flows could