Butte County, CA — Officials have lifted the Evacuation Order for nearly 200,000 people living below the damaged Oroville Dam spillway.
The order has been reduced to a warning. The decision took into account lower lake levels, and updated weather forecasts. However, Butte County Sheriff Kory Honea cautions, “It allows people to return to their homes. Allows people to resume their businesses, but we’re telling them that they have to be vigilant. They have to pay attention to what is going on. There is the prospect that we could issue another evacuation order if the circumstances change and the risk increases.”
Residents were allowed back into their home at 1 p.m. but the sheriff did not elaborate on any plan or schedule for that to happen. The Butte County Sheriff’s Dept. provided this list of factors for making the decision to lift the evacuation order:
The decision to reduce the Immediate Evacuation Order to an Evacuation Warning is based on a number of factors, including:
- Lower lake levels: With the rate of release through the primary spillway remaining at 100,000 cfs, 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 (DWR), the Federal Energy Regulatory Commission (FERC) 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 tomorrow, 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.
Governor Jerry Brown also reacted to a report that surfaced Monday indicating environmentalists raised concerns about the Oroville Dam emergency spillway in 2005. He says he’s glad he found out about the report and adds that it was not part of previous records he had seen. The Governor commented that this as well as other details surrounding the failed spillway will be getting scrutiny over the next few weeks. Asked if more infrastructure and other things will now receive heavier scrutiny and attention, the Governor responded, “Stuff happens and we respond. This is part of the ordinary process and in that sense it will be helpful to stimulate infrastructure analysis and more infrastructure investment.”
(Click here for an earlier story regarding Governor Jerry Brown’s Oroville Dam emergency declaration. )