Santa Fe Dam

Santa Fe Dam

Santa Fe Dam and Reservoir is a flood control project constructed and operated by the U.S. Army Corps of Engineers, Los Angeles District. Construction of the project started in August 1941, but temporarily interrupted in 1943 in deference to military work. Construction resumed in 1946, and the embankment and the spillway were completed in February 1947. Installation of the slide gates was delayed by post-war metal shortages until January 1949. The project is located on the San Gabriel River about 4 miles downstream from the mouth of the San Gabriel Canyon. The San Gabriel River originates on the southern slopes of the San Gabriel Mountains. It flows through precipitous canyons to the base of the mountains, thence across a broad alluvial cone to Santa Fe Reservoir, and through the San Gabriel Valley to Whittier Narrows Reservoir. The Rio Hondo, a distributary of the San Gabriel River, branches from the river just below Santa Fe Dam and flows westward to Whittier Narrows Reservoir. From Whittier Narrows Reservoir, the San Gabriel River flows south to the Pacific Ocean, and the Rio Hondo flows southwestward to the Los Angeles River. Santa Fe Dam and Reservoir was constructed under the authorization of the Flood Control Act of June 1936 (as amended). The project was incorporated into a comprehensive development plan described in the District Engineer's report titled, "Survey Report, Flood Control, Los Angeles and San Gabriel Rivers and their tributaries and Ballona Creek, California", dated 5 February 1940. This comprehensive plan was implemented by the Flood Control Act of 1941.

Santa Fe Dam is an essential element of the Los Angeles County Drainage Area (LACDA) flood control system. The primary purpose of the dam is to provide flood protection for the densely populated area between the dam and Whittier Narrows Reservoir. The flood control operation of Santa Fe Dam is also coordinated with the operation of other Corps dams in the LACDA system, namely Whittier Narrows Dam, Hansen Dam and Sepulveda Dam. Although it has no authorized storage allocation for water supply, its flood control operation provides incidental water conservation benefits to the people of San Gabriel Valley and other parts of the Los Angeles Basin.

Santa Fe Dam contains sixteen 6-foot wide by 9-foot high hydraulically operated slide gates. The combined maximum capacity of the sixteen outlets (with each gate wide open and the reservoir level at spillway crest elevation - 496 feet) is 41,000 cfs. During "stand-by" position, one gate is opened at 0.5 feet and the rest are in a closed position. This gate setting is designed to pass low flows and build a debris pool during high inflows. Discharge rates within the debris pool range allows the Los Angeles County Department of Public Works to divert the flow to its spreading facilities, thereby enhancing water conservation. Once the reservoir level reaches elevation 456 feet, flood control releases are initiated. The dam can release a maximum of 41,000 cfs. During recession, the flood pool is drained as rapidly as possible, consistent with the achievement of downstream flood control. This is done to empty the flood control pool in preparation for the next flood. As soon as the flood pool is drained, releases are reduced so that LACDPW can resume water conservation operation.

Santa Fe Dam's spillway structure is of an overflow concrete ogee type located in the right or northwestern abutment of the dam. The spillway has a crest length of 1,200 feet and a crest elevation of 496 feet. Immediately downstream of the overflow section of the spillway structure is a concrete lined stilling basin. The spillway channel is 1,200 feet wide and extends approximately 5,000 feet from the end of the stilling basin. During spillway flow, the gates are closed gradually to maintain the combination of the spillway flow and outlet works flow to 41,000 cfs.

The current water control manual for Santa Fe Dam was approved in October 1967. Revision of the manual is tentatively scheduled for 2003. The revision will take advantage of the improvements currently underway in the LACDA channels.


Primary Objective   Flood Control Incidental Water Conservation
Completion Date  

January 1949

Stream System   

San Gabriel River

Drainage Area   


Significant Upstream Flood Control Facilities  

Cogswell, San Gabriel and Morris Dams

DSAC Rating   2    
 Elevation NGVD 1929

+ 2.18 feet =

NAVD 1988
  Streambed at dam  




  Debris Pool  




  Spillway crest  




  Revised Spillway design surcharge level6  




  Top of dam  




  Debris Pool  


  Spillway crest  


  Revised Spillway design surcharge level6   1,231 acres  
  Top of dam   1,290 acres  
 Capacity1, Gross      
  Debris Pool   2,679 af  
  Spillway crest   29,651 af  
  Revised Spillway design surcharge level2   44,047 af  
  Top of dam   50,098 af  
  Allowance for sediment (100-year)2   16,000 af  
Dam Type: Earthfill    
  Height above original streambed   92 ft  
  Top length   23,800 ft  
  Top width   30 ft  
Spillway2 Type: Overflow Concrete Ogee    
  Crest length   1,200 ft  
  Revised freeboard6   4.7 ft  
Outlets2 Location Middle of Embankment    
  Gates - type   Hydraulic Vertical Lift    
  Number and size   16 - 6' W x 9'H ft  
  Entrance / Discharge invert elevation   421.0 / 420.0 ft 423.2 / 422.2
  Number and Size   16 - 7' 4" W x 7' 4" H ft  
  Length (total)   515 ft  
  Maximum capacity at spillway crest   41,000 cfs  
  Downstream channel capacity3   41,000 cfs  
Reservoir Design Flood4        
  Duration (Inflow)   5 days  
  Total volume   183,700 af  
  Inflow peak   98,000 cfs  
  Outflow peak   44,000 cfs  
  Maximum water surface elevation   497.4 ft 499.6
Spillway Design Flood ➜   Original5   Resived PMP6
  Duration (Inflow)   1 days 3.5
  Total volume   184,000 af 508,200
  Inflow peak   238,000 cfs 252,200
  Outflow peak   224,800 cfs 248,800
  Maximum water surface elevation   508.4 (510.6 NAVD) ft 508.3 (510.5 NAVD)
Historic Maximums Date      
  Maximum water surface elevation (12-19-1966) 474 ft 476.2
  Maximum storage (46% full) (12-19-1966) 14,4007 af  
  Maximum 1-hour inflow (2-25-1969) 26,400 cfs  
  Maximum outflow (1-26-1969) 26,800 cfs 476.2
1. Based on September 2010 Survey
2. Interim Report on H & H Review of Design Features of Existing Dams for LACDA, June 1978
3. LACDA Feasibility Study Hydrology Appendix, December 1991
4. San Gabriel River Improvement, Santa Fe Dam and Approach Channel, Analysis of Design, Addendum B, May 1944 (prior Hydrology Studies held releases to 19,000 cfs)
5. Hydrology San Gabriel River above Santa Fe Flood Control Basin, December 19405. Hydrology San Gabriel River above Santa Fe Flood Control Basin, December 1940
6. Santa Fe Dam Probable Maximum Flood 2011 Update, August 2011
7. Based on June 1961 Survey