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Bolstering Dam Safety and Flood Protection in California

January 2018

The February 2017 spillway emergency at Oroville Dam amid extreme weather focused national attention on dam safety, flood protection, and the importance of emergency preparedness. Consistent with Governor Brown’s four-point plan to strengthen dam safety and flood protection, the California Department of Water Resources, in coordination with the Governor’s Office of Emergency Services, is carrying out a suite of initiatives to incorporate lessons learned and ensure California remains a leader in dam safety.

Here is a look at the four-point plan and progress to date.

1. Invest in Near-Term Flood Control and Emergency Response Actions

Since 2011, California has invested $3.1 billion to improve the safety of flood control systems, including maintaining and constructing levees. DWR is actively preparing for future flood emergencies and increasing the resiliency of the flood system to address the impacts of climate change and enhance ecosystems. Guided by the updated Central Valley Flood Protection Plan adopted in 2017, these efforts will help improve flood response and enhance flood forecasting through improved understanding of atmospheric river science.

2. Require Emergency Action Plans and Flood Inundation Maps for All Dams

DWR’s Division of Safety of Dams annually inspects 1,249 dams under its jurisdiction and has reviewed and approved more than 200 dam safety projects totaling approximately $2 billion. The 2017 Budget Act included $3.5 million for DWR to review and approve required inundation maps for those jurisdictional dams and coordinate the review of emergency action plans. In July 2017, DWR notified owners of all state-regulated dams of the new requirements for dam inundation maps and emergency action plans and began developing emergency regulations that were approved in October 2017. By January 1, 2021, about 1,000 dams are required to have an approved emergency action plan and inundation maps.

3. Enhance California’s Existing Dam Inspection Program

In June 2017, DWR directed the dam owners of 93 spillways similar to the main flood control spillway at Oroville to conduct a comprehensive assessment of their spillways. Approximately two-thirds of the 93 dam owners completed needed maintenance repair work prior to the current winter season in conjunction with their ongoing condition assessments. DWR publicly released the updated hazard potential, condition assessment, and restriction status of all jurisdictional dams in September 2017. More spillways will be evaluated as the program progresses, and additional dam safety components and systems that pose the highest risk to the public will continue to be evaluated.

4. Seek Prompt Regulatory Action and Increased Funding from Federal Government to Improve Dam Safety

While the U.S. Army Corps of Engineers works to finalize an update to its reservoir regulation procedures (also known as rule curves), DWR is operating under its approved winter operations plan for Oroville. DWR will coordinate with the Corp for approval of interim operations plans until the rule curve can be completely updated.