Oroville Dam evacuation order ended; residents can return
February 14, 2017
• Butte County sheriff says it is now a “warning”
• Dam repairs, lower lake level credited
Due to lower lake levels, further inspections, ongoing work to shore up the Oroville Dam emergency spillway and updated weather forecasts, the evacuation order that sent 180,000 residents packing Saturday night has been refused to an “evacuation warning,” allowing residents to return to their homes and businesses to reopen, the Butte County Sheriff’s Office says Tuesday afternoon.
However all residents are advised to remain vigilant and prepared as conditions can rapidly change. People who have special needs or require extended time to evacuate should consider remaining evacuated, the sheriff’s office says.
An “evacuation warning” means the immediate threat has ended but the potential for an emergency remains and therefore residents must remain prepared for the possibility of an evacuation order.
Tuesday’s decision is based on a number of factors, including:
• Lower lake levels
With the rate of release through the primary spillway remaining at 100,000 cubic feet per second, over the last two days the lake level has dropped 12 feet below the top of the auxiliary spillway and no longer has water flowing over the top. This mitigation work will reduce the risk of erosion should the emergency spillway have to be used again, although flow through the primary spillway will continue to attempt to lower the reservoir to 851 feet (approximately 50 feet below full).
• Further inspections
With the water level reduced, geologists and dam safety engineering specialists from the Department of Water Resources, the Federal Energy Regulatory Commission and the United States Army Corps of Engineers were able to inspect the damage. That inspection revealed that the integrity of the emergency spillway was not compromised by the erosion.
• Ongoing work to shore up emergency spillway
To prevent further erosion the DWR is lining the front of the spillway with boulders and concrete. That work is expected to be completed Wednesday, ahead of the forecasted stormy weather.
• Updated weather forecasts
The decision has taken into account updated weather forecasts. The storm expected later this week is forecasted to be colder, with less rain and therefore a lower level of water flow into the reservoir than last week.
An evacuation center will remain open at the Silver Dollar Fairgrounds in Chcio. All other evacuation centers supported by Butte County will be closed. Residents from other centers who are still seeking shelter due to the evacuation warning can go to the Silver Dollar Fairgrounds.
Residents who evacuated animals to the Silver Dollar Fairgrounds should collect their animals as soon as possible if returning home. Large animals can remain at the evacuation center, but owners are advised to secure an alternative location for animals that is outside the area under the evacuation warning.
Local agencies and medical facilities are determining when patients can be returned to evacuated hospitals and skilled nursing facilities.