Department of Water Resources Home

Frequently Asked Questions

Division of Safety of Dams
Department of Water Resources

Street Address:
2200 X Street, Suite 200
Sacramento, CA 95818

Mailing Address:
P.O. Box 942836
Sacramento, CA 94236-0001

Telephone #: (916) 227-4644

E-Mail General Information:

General Information Questions

• Who in the Division should correspondence be addressed to?

All correspondence should be directed to Sharon K. Tapia, Chief of the Division of Safety of Dams, at 2200 X Street, Suite 200, Sacramento, California 95818.

• Why are annual fees needed and what do they fund?

Since 2003, the dam safety program has been funded entirely from the combination of dam application fees and annual fees. Senate Bill 1049 (Chapter 741, Statutes of 2003) set forth the general fee structure which, is periodically adjusted for cost of living increases, as outlined in Section 6307 of the Water Code.

These fees support a wide variety of activities, including the monitoring of dams in certified status, application review and construction inspection work, and engineering studies which include hydrologic, structural, and seismic stability re-evaluations. The percentages for the foregoing activities are generally 35, 35, and 25 percent, respectively. The remaining portion funds our general administrative office costs.

• How does the Division ensure the safety of dams in California?

The Division has several programs that ensure dam safety. When a new dam is proposed, Division engineers and geologists inspect the site and the subsurface exploration to learn firsthand of the geologic conditions. Upon submittal of an application, the Division thoroughly reviews the plans and specifications prepared by the owner to ensure that the dam is designed to meet minimum requirements and that the design is appropriate for the known geologic conditions. After approval of the application, the Division oversees the construction to ensure the work is being done in accordance with the approved plans and specifications. Following construction, the Division inspects each dam on an annual basis to ensure the dam is safe, performing as intended, and is not developing problems. Roughly a third of these inspections include in-depth instrumentation reviews of the dam surveillance network data. Lastly, the Division periodically reviews the stability of dams and their major appurtenances in light of improved design approaches and requirements, as well as new findings regarding earthquake hazards and hydrologic estimates in California.

• What does the Division do if a dam appears unsafe?

We work closely with dam owners to identify and correct most potential problems before they become more serious. When notified of a potentially unsafe condition, we will inspect the dam and depending on the circumstances, we may initiate or require a follow-up investigation. When unsafe conditions develop, we work with owners and their consultants to address and remedy the condition in a timely manner. To minimize risk, we may impose a reservoir restriction limiting the water surface to a level that is judged safe. We may direct the dam owner to implement their emergency action plan (EAP), or request that they develop one in coordination with local authorities.

• Will an application be required for my planned alteration or repair work?

Possibly - contact the respective Area or Regional Engineer for clarification. As a general guideline, an application will be required if the work entails more than routine maintenance work and significantly affects the dam or its appurtenances.

Some examples of work requiring an alteration application include:

• Abandoning or replacing the outlet conduit
• Modifications to the outlet system which will affect emergency draw down requirements
• Significant penetration(s) of the water barrier
• Excavation of more than a few feet into the embankment

Exploration and drilling activities associated with installation of instrumentation are handled on a case-by-case basis. Our prior review and approval are required for such activities regardless of the need for an application.

• When should the construction fee be submitted?

A construction fee must accompany the application in order for our review to proceed. For new or enlarged dams, we generally require that the full construction fee be submitted by the time the 30% design submittal is made. Staged fee installments can be arranged, commensurate with the design stage, for major projects when the design phase will exceed one year.For repairs, alterations, and removals the full construction fee should be submitted with the application. The filing fee for an application is based upon the estimated cost according to the following schedule (PDF)

• Does your agency oversee water rights or issues pertaining to water diversions?

No, not directly. We work with the State Water Resources Control Board’s Division of Water Rights (SWRCB) to verify that appropriate water rights have been obtained before we issue a Certificate of Approval authorizing storage to a specified level. Questions concerning the actual water rights should be directed to the SWRCB. The link to their website is:

• I just purchased a property having a jurisdictional-size dam – do I need to initiate any action?

Yes, you should start by notifying the respective Area Engineer of this change. You will need to complete an Ownership Statement Form, and submit it to us immediately.

Assistance-Related Questions

• How can I arrange to review your files for this dam?

Contact our File administrator at (916) 227-4695, to set up an appointment. We have one office statewide, located at 2200 X Street, Suite 200, Sacramento, CA 95818.

• Can you recommend an engineering consultant for me?

We don’t recommend any specific individual or firm, but we can provide names of consultants that have worked, or are working on nearby projects. We also recommend that you check out the following organizations and websites:

California Society of Professional Engineers
Telephone Number (916) 422-7788

Consulting Engineers and Land Surveyors of California
Telephone Number (916) 441-7991

California Board for Professional Engineers and Land Surveyors
Telephone Number (916) 263-2222

• How can I determine whether my property would be flooded or inundated from a failure of this dam?

Inundation maps are available for most large dams. We do not review or oversee preparation of these maps. However, Government Code Section 8589.5 requires dam owners to submit copies of inundation maps to the Governor’s Office of Emergency Services. Copies of these maps are also provided to the appropriate public safety agency of any city and/or county likely to be affected. Most local agencies overlay these inundation maps onto their parcel map systems. Therefore, we recommend that you contact your local emergency management office using the web site.

• Can you tell me if the Division checks this particular dam, and if so, how often?

Yes, we will work with you to determine if the dam in question is under our jurisdiction. You can assist us greatly by providing us with the dam name, affected water course, nearby town, and county in which the dam is located. As part of our normal routine maintenance program, we generally inspect all jurisdictional dams at least once per year. High hazard dams are typically inspected twice a year, and special inspections may be made in response to follow-up work. Currently, there are approximately 1,250 dams in California that fall under our jurisdiction. A listing of these dams is on our home page.

If the dam height is more than 6 feet and it impounds 50 acre-feet or more of water, or if the dam is 25 feet or higher and impounds more than 15 acre-feet of water, the dam will be under our jurisdiction unless it is federally owned or exempted under special provisions described in Sections 6004, 6025, or 6026 of the California Water Code. Graphical information that summarizes the above can be found on our Jurisdictional Size Chart page.

• What should I do if I observe suspicious activity on or around a dam?

Immediately contact your local law enforcement agency (dial 911). The dam owner should also contact us if any significant dam safety issues arise from this activity.

Technical Guidance Questions

• I am planning to build a small jurisdictional-size earth dam. What sort of geotechnical exploration is needed?

A typical field investigation should seek to identify geologic hazards that could adversely affect the project, to characterize the engineering properties of available earth and rock construction materials, and to characterize the strength and permeability of the dam, spillway, and outlet foundations. Since each site and project is unique, exploration plans should be submitted to DSOD beforehand for review. DSOD should also be given the opportunity to observe the site conditions firsthand during exploration.

A typical field investigation program includes understanding the geology of the site through geologic mapping, air photo analysis, test pits, and borings. The engineering properties of embankment and foundation soils are generally evaluated by sampling and laboratory testing, and field testing such as in-place density, penetration resistance, and permeability testing. Geophysical techniques, such as seismic refraction and shear wave velocity testing are sometimes used. Core drilling and water pressure testing may be required for rock foundations. A phased investigation is often the most effective way to evaluate the geologic conditions and engineering properties of a site.

• What are the Division’s requirements for outlet operation?

Our policy requires that dam owners regularly exercise (operate) their outlets in order to demonstrate the ability to draw down the reservoir during an emergency. Outlet controls should be exercised at least annually and, in our presence, every three years. Experience has proven that regular exercising of gates/valves help prevent major maintenance problems from developing and is therefore, part of a good maintenance program.

We do not operate the outlet controls themselves, nor order their operation during routine inspections. It is the responsibility of the dam owner to develop appropriate plans and make the necessary arrangements when dealing with difficult outlet situations. We accommodate reasonable delays in exercising of outlets so owners have time to complete proper planning, coordinate with other agencies, and perform maintenance and repairs, if necessary.

Dam owners should maintain a log detailing all operation and maintenance activities for their outlet system.

• Does the Division have specific outlet dewatering requirements for large dams/reservoirs?

Yes, our guidelines are summarized below:

For reservoirs that impound 5,000 acre-feet of water or less, the outlet system should be capable of draining half of the reservoir capacity in 7 days and full contents within 20 days.

For reservoirs that impound over 5,000 acre-feet of water, the outlet system should be capable of lowering the maximum storage depth by 10 percent within 7 days and draining its full contents within 90 days.

These guidelines are evaluated on a case-by-case basis; particularly for the very large reservoirs that are in excess of 100,000 acre-feet.

• How is dam height determined when evaluating jurisdictional status?

Jurisdictional height of a dam is the vertical distance measured from the lowest point at the downstream toe of the dam to its maximum storage elevation which is typically the spillway invert elevation. This same approach is also used for calculating the dam height for determining the annual fee.