Lopez Spreading Grounds Basin Improvement Project

Picture of Lopez Spreading Grounds


Lopez Spreading Grounds was built in the mid-1950s and is an 18-acre water conservation facility that provide groundwater recharge for the San Fernando Basin. Currently, the spreading grounds' percolation rate is reduced due to a low permeability clay layer underlying the infiltration basins. The proposed project will increase the spreading grounds' storage capacity and percolation rate and simplify operations by combining basins.

Primary project objectives include:

  • Expanding storage capacity by combining and deepening the existing 6 basins into 5 larger basins.
  • Increasing the percolation rate from 10 cfs to 14 cfs by removing existing clay layers underlying the spreading grounds.
  • Increasing storage capacity of the spreading grounds from 24 acre-feet to 73 acre-feet by combining and deepening the existing 6 basins.
  • Modifying the diversion structure and installing slide gates with electric motor operators.
  • Preventing erosion by lining the intake canal with concrete.

The project is funded by a State Proposition 84 grant through IRWMP, the Los Angeles Department of Water and Power, and Los Angeles County Flood Control District.


Attention: Nayiri Vartanian
Los Angeles County Flood Control District
900 South Fremont Avenue, 11th Floor
Alhambra, CA 91803

Email: SpreadingGrounds@dpw.lacounty.gov

Fax: (626) 457-1526



For more information on the project or to be added to the project mailing list, please contact SpreadingGrounds@dpw.lacounty.gov