On June 27, 2017, Governor Brown signed SB 92 into law, which set forth new requirements focused on dam safety. As part of this legislation, dam owners must now submit inundation maps to DWR. After the maps are approved, the dam owner must submit an emergency action plan to Cal OES. The owner must submit updated plans and inundation maps every 10 years, or sooner under certain conditions. Cal OES will review and approve the emergency action plans. This legislation set forth additional provisions for emergency action plans including compliance requirements, exercises of the plan, and coordination with local public safety agencies.
Message from the Division of Dam Safety, Department of Water ResourcesSenate Bill 92 added Sections 6160 and 6161 to the Water Code that became effective on June 27, 2017, requiring owners of State regulated dams, except those classified as low hazard, to prepare emergency action plans (EAPs) containing inundation map(s) for emergency preparedness. On October 19, 2017, emergency regulations were adopted to provide standards for preparing and submitting maps to the Division of Safety of Dams (DSOD) for their review and approval. These regulations are available at http://www.water.ca.gov/damsafety/statutes_regulations/index.cfm. Dam owners must submit EAPs to the Governor’s Office of Emergency Services (Cal OES) for approval by deadlines that are based on the dam’s downstream hazard classification. Dam owners received letters in July identifying their dam’s hazard classification and the statutory deadlines for EAPs as shown below: · Extremely high hazard dams: January 1, 2018· High hazard dams: January 1, 2019· Significant hazard dams: January 1, 2021 It is important to note that inundation maps must first be submitted to DSOD for review and approval, and only approved inundation maps should be contained within EAPs that are submitted to Cal OES for their approval. Upon approval of the EAP by Cal OES, dam owners are responsible for ensuring that the approved EAP is disseminated to appropriate public safety and emergency management agencies, which includes DSOD. Thank you for your cooperation. If you have any questions or need additional information, please contact DSOD Design Engineer Kristen Martin at (916) 227-2170 or MapRegs@water.ca.gov.
Most dam owners are required to prepare inundation maps as part of the dam permitting process. These maps are prepared by civil engineers on behalf of dam owners, as required under California law. State law requires dam owners to submit inundation maps for approval by Cal OES. Inundation maps are developed from the best available information using reasonable assumptions and standardized methods. The maps are an approximation of the maximum water flow resulting from a complete dam failure. The maps portray a catastrophic failure of the dam, as opposed to the failure a critical appurtenant structure, such as a spillway. This map represents a worst-case scenario contemplating a complete failure of the Oroville Dam. Depending upon actual circumstances, appropriate alert and evacuation areas could be more or less extensive than the simulated zones shown on the maps.
Inundation Map for Oroville Dam 2016.pdf
Dam Data Requests
To request dam inundation data, please submit a Public Records Act request. Please contact Jennifer Plescia, Attorney, at (916) 845-8815, or Alex Pal, Attorney, at (916) 845-8973, or send an email to: PRA@caloes.ca.gov.
For other information on dam emergency action planning, please contact the Dam Emergency Action Planning Division at email@example.com.
For information on dam inundation mapping, please refer to the DSOD website.
Federal Guidelines for Dam Safety: Emergency Action Planning for Dams
Water Codes §6160, 6161, 6162
Government Code §8589.5
The Cal OES Dam Inundation Mapping & Emergency Procedure (DIMEP) Program was established by Government Code §8589.5 in 1972 following a near failure of the Lower San Fernando Dam during the Sylmar Earthquake. The program provided assistance and guidance to local jurisdictions on emergency planning for dam failure events by:· Collecting and reviewing dam failure inundation maps · Evaluating waivers from the inundation mapping requirements
The DIMEP Program coordinated with the California Department of Water Resources (DWR), Division of Safety of Dams (DSOD) and other state and federal agencies in activities to assure effective dam incident emergency response procedures and planning.
The DIMEP Program was also the designated repository of the official dam failure inundation maps used in California’s Natural Hazard Disclosure statement.
SB 92 superceded this previous legislation and removed our authority to review and approve dam inundation maps, giving that responsibility to DSOD.