Fact Sheet

O&M - Santa Ana River Basin, CA

U.S. Army Corps of Engineers, Los Angeles District
Published April 16, 2023

The Santa Ana River Basin (SARB) Project, as operated and maintained by the Corps includes 16 miles of channels and levees and 5 flood risk management dams. Project features
are located in Orange, Riverside and San Bernardino Counties, California.

1. BREA DAM: Located 2 miles north of the city of Fullerton. Project Elements: Dam and Appurtenances (87-feet-high; 1,765-feet-long; 4,009-acre-feet cap at spillway crest –
1964), 1 Recreation Area - # of visitors to Recreation Area in FY22 was 519,098. Fully Operational FY42.

2. CARBON CANYON DAM: Located 16 miles NE of the City of Santa Ana. Project Elements: Dam and Appurtenances (99 feet-high; 2,150-feet-long; 6,614-acre-feet cap at spillway crest - 1977), 1 Recreation Area - # of visitors to Recreation Area in FY22 was 400,230. Fully Operational FY61.

3. FULLERTON DAM: Located in the eastern part of the city of Fullerton just west of the 57 Freeway and Bastanchury Road crossing. Project elements: Dam and Appurtenances (46 feet-high; 575 ft-long; 764 acre-feet cap at spillway crest 1969), 1 Recreation Area - # of visitors to Recreation Area in FY22 was 366,970. Fully Operational FY41.

4. PRADO DAM: Located on the Santa Ana River approximately 30.5 miles (49 kilometers) upstream of the Pacific Ocean. Project elements: Dam & Appurtenances (106 ft-high; 2,280 ft-long; 196,235 acre-ft cap at spillway Crest - 1980), 3 Recreation Areas - # of visitors to Recreation Areas in FY22 was 2,802,410. Fully Operational FY41.

5. SAN ANTONIO DAM: Located 7 1/2 miles N of the City of Pomona. Project elements: Dam and Appurtenances (160 ft-high; 3,850 ft-long; 7,703 acre-ft cap at spillway crest 1981). No recreation areas. Fully Operational FY56.

6. SAN ANTONIO AND CHINO CREEKS CHANNELS: Located 30 miles E of the City of Los Angeles. Project elements: 15.7 miles of channel. No recreation areas. Fully Operational FY61.

AUTHORIZATION: Flood Control Act of 1936 (as amended 1938)

ACTIVITIES FOR FY 2023: Funds used for routine O&M; dam safety oversight; program/project management. Non-routine activities include vegetation management/debris removal within SARB Dams and Levees/Channels; completion of Prado Master Plan; construction/O&M QA.

IIJA ACTIVITIES: Expand maintenance yard fencing, install vehicle/pedestrian gates, and install lighting at San Antonio Dam; replace/repair fencing at SARB dams/channels as required; inspect sewer systems at SARB Dams; repaint bridge supports at Fullerton Dam; perform vegetation management/debris removal within Chino Creek Levee.

FY24 PLANNED ACCOMPLISHMENTS: Optimal funding would be used for:
OPERATION – Funds would be used for minimal operational and maintenance requirements; Environmental/resource land management; water control and quality management; inspections of outgranted areas and rights of ways; oversight of land outgrants, conduct compliance and utilization inspections of real property, conduct real property accountability inspections, including real property inventory, and ESA compliance; dam safety oversight; project/program management.

MAINTENANCE - Funds would be used for servicing facilities and to conduct minimum level maintenance requirements: repair fencing (as needed in Basins), Dam Inspection and service (Electrical and Mechanical) per O&M manual, clear vegetation around log boom and mow operations area for fire safety, clear vegetation 50' from toe of dam per EP 1110-2-18, clear vegetation 15' from channel walls and concrete structures per EP 1110-2-18, clear vegetation 15' from center line of abutments. EP 1110-2-18, clear 15' both side of V-ditch from gravel seepage blanket, clear vegetation from upstream/downstream embankments per EP 1110-2-18, clean out existing material in weep holes and replace with 3/4" rock, clear upstream apron and trash racks of sediment/debris, grade all access roads, patch cracks and re seal where needed, Inspect/repair drainage gallery conduit and manhole, maintain clearance around all relief wells and manholes, clear/spray weeds in gravel seepage blanket, clear vegetation and debris at concrete weir, repair/clear around staff boards, and inspect/repair outlet conduit/apron.

ISSUES AND OTHER INFORMATION: The Los Angeles District operates and maintains 5 dams in SARB that reduce the risk of flooding approximately 2.7 million people and $114 billion in property within Los Angeles County, Orange County, Riverside County, San Bernardino County. These dams were constructed 60 to 80 years ago. Routine operation, maintenance, and inspection activities are performed at each dam. However, they are not exempt from the downward trend associated with the nation’s aging infrastructure and are in need of rehabilitation of dam components, such as hydraulic systems, motors, gates, and generators. Current project funding received through the O&M program does not meet growing deferred maintenance requirements for the five flood risk management projects and 15.7 miles of flood control channels and levees within the flood control system. The project is currently funded at less than 25% of O&M capability; causing a continued increase in deferred maintenance, repairs, and inspections needed to properly O&M the SARB system.

These dams are reviewed periodically and rated according to the age and condition of the dam and potential downstream consequences. The SARB dams range from low to high urgency of action. Carbon Canyon Dam and Prado Dam currently have a high urgency of action (DSAC 2); Brea Dam and San Antonio Dam have a low urgency of action (DSAC 4); Fullerton Dam was reclassified from low urgency (DSAC 4) to normal (DSAC 5) in December 2021.

The Dam Safety Action Classification or DSAC is a rating system that provides consistent and systematic guidelines to address dam safety issues of all 700 Corps owned and operated dams. This process enables us to prioritize dam safety actions to correct deficiencies, which include interim risk-reduction measures to be undertaken while further investigations are conducted and remedial actions are implemented.

The Prado Dam and Reservoir project is authorized primarily for flood risk management, but it is also operated, when there is opportunity, to benefit water conservation. The water conservation pool (also called the “buffer pool”) impoundment occurs only in relationship to urban runoff generated from rain events. And like the runoff impoundment stored for flood runoff, the buffer pool storage is also temporary, and drained completely in coordination with the Orange County Water District for their capture into their groundwater recharge facilities.

Currently, there is a Feasibility Study to propose increasing the flood season buffer pool behind Prado Dam, from elevation 498, up to elevation 505 feet, NGVD29. There is also an approved multi-year major deviation in place to implement this proposed operation change to the water control plan now while the Feasibility Study is ongoing. Upon completion of the Feasibility Study and approval of the increased buffer pool storage alternative, the approved deviation plan currently in place will become a permanent part of the project operation. The proposed increase to the buffer pool storage volume is less than 6% of the entire flood risk management pool. Operating the project for water conservation does not interfere with its capability to provide flood protection to the downstream communities.

1. Prado Dam Mural
• Prado Mural Abatement – 100% complete as of December 2022.
• Executed 5-year (March 2023 – March 2028) license agreement to Riverside County to re-paint, operate and maintain new mural. Mural repainting is tentatively scheduled to start late March 2023 with an early May 2023 completion date.

2. Santa Ana River Trail (SART)
• Betterment request from Local Sponsor accepted as part of the Prado Dam Spillway Modifications Project in Dec 2022.
• The project delivery team (PDT) submitted the 30% design package to Riverside in Jan 2023 and is continuing to work on the drawings.
• Environmental will create a separate Environmental Assessment for this portion of the trail (Phase 3B).

3. Prado Basin Homeless Encampments
• No planned actions at this time due to bird nesting season (Mar 15th – Sept 15th).
• Corps staff will continue to coordinate with City of Corona and Corona Police Department on future homeless encampment removals.

As of 01 MAR 23

Estimated Federal Cost            $ 10,787,730

Estimated Non-Federal Cost                             0
Total Estimated Project Cost        $ 10,787,730

  Allocation thru FY22          $ 10,335,280
President’s Budget for FY23        $ 7,253,730 1/
Conference Add for FY23                            $0
Approved IIJA FY23            $ 2,084,000
Workplan for FY23            $ 1,450,000

President's Budget for FY24     $12,560,130 2/ 
Approved IIJA FY24               $ 50,0000
Workplan for FY24                         TBD
Balance to Complete After FY24                          N/A
1/ Decreased 1% from $ 7,327,000
2/ Decreased 1% from $12,687,000


CONGRESSIONAL INTEREST: Senators Butler and Padilla; Representatives Chu (CA-28), Kim (CA-40), Calvert (CA-41), Steel (CA-45)



Congressional Liaison