Folsom Dam

Folsom Dam Raise Project

The U.S. Army Corps of Engineers Sacramento District is moving forward with the Folsom Dam Raise Project to help further reduce flood risk in the Greater Sacramento area.  The overall project includes the following authorized components: a three-and-a-half foot raise of the Folsom Facility dikes, Mormon Island Auxiliary Dam (MIAD), Left Wing Dam (LWD), and Right Wing Dam (RWD), along with modifications to the main dam’s Tainter gates; construction of automated temperature control shutters at the main dam to benefit American River fisheries, and; habitat restoration at two sites along the lower American River - Bushy Lake Restoration Site and Woodlake Restoration Site.  The overall project also included construction of the Folsom Dam Bridge, which was completed in 2009.

The Dam Raise Project has prioritized completion of the remaining flood risk reduction elements of the overall project, which include raising the existing crest elevation of Dikes 1 through 8, MIAD, LWD, and RWD by approximately 3.5 feet, plus various structural changes to Folsom Dam (primarily modifications to the Tainter gates situated near the crest of the dam).  This work is expected to enhance utilization of Folsom Lake’s existing surcharge flood storage space and increase the temporary water storage space that can be used during flood events.

The Corps, in coordination with the California Central Valley Flood Protection Board and the Sacramento Area Flood Control Agency, has prepared a joint Supplemental Environmental Impact Statement/Environmental Impact Report (SEIS/EIR) for the flood risk reduction elements of the Dam Raise Project mentioned above.  The draft SEIS/EIR was first released for public review in July 2016.  This version of the SEIS/EIR underwent substantial revisions following the original review period.  The revised draft SEIS/EIR was released for public review in June 2017. The Corps released the final SEIS-EIR in October 2017. The record of decision was signed in December 2017. 

Upcoming Public Meetings


Folsom Dam Raise Modifications Project Draft Supplemental EIS/EIR

Folsom Dam Raise Modifications Project Draft Appendices

Federal Register Notice of Availability

We are making the 2021 Draft Supplemental EIS/EIR available to potentially interested agencies, stakeholder organizations, and the public, for a 45-day review period from November 12, 2021 to December 27, 2021.

A virtual public meeting will be held on December 2, 2021 at 4:00 PM to discuss the Proposed Project and accept public questions.

You may join the meeting as early 3:45 p.m. PST so that meeting organizers may address any technical issues you have connecting to the meeting. You may join the meeting late but technical assistance may not be available.

For Webinar: Access the webinar here, or copy and paste into a web browser, enter Meeting Number: 1991 18 1198 and Password: Folsom21!

Enter your name, email address, and affiliation (community member, employee of interested agency, etc.). When prompted, you must ask the system to call you back if you would like to use audio during the meeting. The audio on your computer may not work – try phone access also.

Please see below for call-in instructions:

For Teleconference (Toll-free): 1-844-800-2712

Caller Paid and International: 1-669-234-1177

Access Code on prompt: 1991 18 1198

If callers experience any technical difficulties, please hang up and call again. If you need technical assistance, call the AT&T Help Desk at 1-888-796-6118.

Americans with Disabilities Act accommodations or translation services are available for individuals with hearing or speech disabilities by calling 7-1-1, a free nationwide telecommunications relay service (TRS). For other accommodations, please email your request 72 hours in advance to

Teleconferences will be recorded. By speaking, you automatically consent to such recordings. Messages in the chat will also be recorded and be public.

The slide presentation for the meeting is available here.

Comments on the Draft Supplemental EIS/EIR will be accepted from November 12, 2021 to December 27, 2021. The 2021 Draft Supplemental EIS/EIR is available at:

Written comments on the 2021 Draft Supplemental EIS/EIR must be directed to the name and address below via postal mail or email by no later than 5:00pm on December 27, 2021:

Flood Projects Branch                                                            Public Affairs Office

Department of Water Resources                                           U.S. Army Corps of Engineers

3310 El Camino Avenue Room 200               -- OR--             1325 J Street Room 1513

Sacramento, CA 95821                                                          Sacramento, CA 95814

email:                                     email:

If comments are provided via email, please:

  • Indicate “Folsom Dam Raise Modifications Project” in the subject line
  • Attach comments in Microsoft Word format
  • Include the commenter’s name and mailing address. For comments by agencies and organizations, please include the name of a contact person for the agency or organization.

All comments received, including names and addresses of commenters, will become part of the official administrative record and may be available to the public.

Contact Information

For more information on the
Folsom Dam Raise project,
please contact us at the following:



Mailing Address:
U.S. Army Corps of Engineers,
Sacramento District
Folsom Dam Raise
1325 J Street, Room 1513
Sacramento, CA  95814