Inundation Mapping and Emergency Action Plan – a California Dam Safety Initiative

The California state legislature passed Senate Bill (SB) 92 effective July 1, 2017, which mandates that all owners of state jurisdictional dams, other than those classified as “low hazard” by the California Department of Water Resources (DWR) Division of Safety of Dams (DSOD), must provide DSOD with a set of prescribed inundation maps. These maps must show inundation from failure of the dam and also the critical appurtenant structures (CAS), such as spillways and other outlets. Once approved by DSOD, these maps are to be incorporated into EAPs. The EAPs must, in turn, be submitted to the California Governor’s Office of Emergency Services (Cal OES).
In order to comply with SB 92 mandate and also to improve the State Water Project (SWP) Dam Safety Program (SWP DSP), DWR’s Division of Operations and Maintenance (O&M) has prepared inundation maps for all “extremely high hazard” and “high hazard” SWP dams and their CAS to achieve conformance with Title 23, Division 2, Chapter 1, Article 6 of the California Code of Regulations. In a parallel effort, O&M is also either developing new EAPs or updating existing EAPs for all SWP dams. This presentation provides a chronology of key efforts taken by O&M and the major milestones achieved towards inundation mapping and EAP development.