You are here

California Senate Bill 92 and New Standards for Submitting Dam Inundation Maps

Client Alert

On October 19, 2017, emergency regulations were adopted to provide standards for preparing and submitting inundation maps to the Division of Safety of Dams (DSOD) for review and approval pursuant to Senate Bill 92.

On June 27, 2017, SB 92 became effective and added Sections 6160 and 6161 to the Water Code, 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.  The EAPs, including the inundation map(s), are to be updated every ten years, but if relevant circumstances change, then the update must be made sooner.  SB 92 provides the Department of Water Resources with enforcement tools, including fines and operational restrictions for failure to comply.  SB 92 states costs associated with compliance are not reimbursable as unfunded State mandates. 

Further, SB 92 requires that if a dam is owned by one or more persons or entities, the owners shall form or delegate legal and financial authority to a single entity responsible for the operation and maintenance of the dam, as well as the payment of any fees or costs associated with dam ownership.  SB 92 places no express limitation on a public agency using its own staff to perform capital construction projects.

Inundation Maps

An inundation map refers to a map showing the area that would result in flooding from a failure scenario.  A failure scenario refers to the modeled simulation of a complete failure of a dam or critical appurtenant structure which results in the uncontrolled release of water.

Emergency Action Plans

An EAP contains a blueprint for emergency response following an incident involving a dam and details various failure scenarios of a dam and its related critical infrastructure.  It provides special notification procedures.  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

However, if an owner of a dam had an existing EAP as of March 1, 2017, DSOD will review an inundation map contained in that plan.  If DSOD determines the inundation map is sufficient, DSOD shall request Cal OES to review the EAP associated with that inundation map.

SB 92 Practical Implications

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.

The new regulations for inundation map standards are available at:

For more information on the Cal OES EAP program, please visit


For further information, please contact Christine M. Carson or Gabriel Pitassi from Aleshire & Wynder, LLP’s Water Practice Group at (949)223-1170.

Disclaimer:  Aleshire & Wynder, LLP legal alerts are not intended as legal advice.  Additional facts or future developments may affect subjects contained herein.  Please seek legal advice before acting or relying upon any information in this communication.