Spreading Grounds

In addition to the flood control program, Public Works has the equally important mission of conserving as much of the storm and other waters as practicable. The use of water conservation facilities or spreading grounds adjacent to river channels and in soft-bottom channels permits water to percolate into groundwater basins for later pumping. These groundwater recharge facilities are located in areas where the underlying soils are composed of permeable formations and in hydraulic connection with the underlying aquifer.

The importance of this activity is apparent when it is realized that about 30 to 40 percent of the water used in the County is pumped from groundwater supplies. The growth of the County, combined with periodic droughts, has seriously depleted these supplies on numerous occasions. Public Works' policy is to conserve the maximum possible amount of storm water consistent with runoff quantity and quality, capacities of the spreading facilities, and groundwater conditions. The locations of Public Works' 26 Spreading Grounds Facilities are shown on the map.

List of Public Works' Spreading Grounds Facilities

  1. Ben Lomond Spreading Grounds
  2. Big Dalton Spreading Grounds
  3. Branford Spreading Basin
  4. Buena Vista Spreading Basin
  5. Citrus Spreading Grounds
  6. Dominguez Gap Spreading Grounds
  7. Eaton Spreading Basin
  8. Eaton Wash Spreading Grounds
  9. Forbes Spreading Grounds
  10. Hansen Spreading Grounds
  11. Irwindale Spreading Grounds/Manning Pit
  12. Little Dalton Spreading Grounds
  13. Live Oak Spreading Grounds
  1. Lopez Spreading Grounds
  2. Pacoima Spreading Grounds
  3. Peck Road Spreading Basin
  4. Rio Hondo Coastal Spreading Grounds
  5. San Gabriel River (Montebello Forebay)
  6. San Dimas Canyon Spreading Grounds
  7. San Gabriel Canyon Spreading Grounds
  8. San Gabriel Coastal Spreading Grounds
  9. Santa Anita Spreading Grounds
  10. Santa Fe Spreading Grounds
  11. Sawpit Spreading Grounds
  12. Valley Boulevard Rubber Dam
  13. Walnut Spreading Basin

Other facilities operated in conjunction with Public Works

  1. Fish Canyon Spreading Grounds (Committee of Nine)
  2. Sierra Madre Spreading Grounds (City of Sierra Madre)
  3. Thompson Creek Spreading Grounds (Pomona Valley Protective Association)
  4. Tujunga Spreading Grounds (Los Angeles City Dept. of Water & Power)


Spreading Grounds information: basin type, number of basins, gross and wetted area, capacities, location, & source of water. View list  


Monthly figures for imported, reclaimed, and total water conserved via groundwater recharge. View data  

Data and unpublished information for these facilities can be obtained by contacting the custodian of hydrologic record:

Telephone: (626) 458-6120