Pacoima Spreading Grounds Improvement Project

Picture of Pacoima Spreading Grounds

Project Summary

Pacoima Spreading Grounds was built in the 1930s and is one of the major water conservation facilities that provide groundwater recharge for the San Fernando Groundwater Basin. Currently, the spreading grounds' percolation rate is reduced due to a low permeable clay layer underlying the spreading basins. The proposed project will increase the spreading grounds' storage capacity and percolation rate and simplify operations by combining basins and constructing new interbasin structures.

The proposed project will result in increased groundwater recharge in the San Fernando Groundwater Basin. Primary project objectives include:

  • Increasing the percolation rate from 65 to 140 cubic feet per second by removing the underlying clay layers in the spreading basins;
  • Expanding the storage capacity of the spreading basins from 530 to 1,200 acre-feet by combining and deepening the spreading basins;
  • Modifying the intake structure between the channel and the spreading basins to enhance operations;
  • Installing tubular perimeter fencing; and
  • Constructing a new bike path along Pacoima Diversion Channel, between Devonshire Street and Filmore Street to improve neighborhood connectivity.

This project is funded by the State Proposition 84 grant through the Integrated Regional Water Management Plan (IRWMP), the Los Angeles Department of Water and Power, and the Los Angeles County Flood Control District.

Construction Photos

Announcements / Construction Updates

Monday, July 1, 2024

  • Hauling operation continues at the Project site.
  • Permanent roads within the facility are being paved.
  • Electrical work continues for site.
  • Contractor is installing the new perimeter fencing, gates, and stone pillars.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Thursday, March 21, 2024

  • Hauling operation continues at the Project site.
  • Access roads within the facility are being paved.
  • Structural, mechanical, and electrical work continues for site and overflow structures.
  • Contractor is installing the new perimeter fencing and stone pillars.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Thursday, December 14, 2023

  • Hauling operation continues at the Project site.
  • Access roads within the facility are being paved.
  • Structural and mechanical work continues, electrical work commenced for site and overflow structures.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Thursday, September 07, 2023

  • Hauling operation continues at the Project site.
  • Structural and mechanical work continues.
  • Paving of the exterior perimeter outside basins has commenced.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Monday, June 12, 2023

  • Hauling operation continues at the Project site.
  • Structural work continues on the Headworks infrastructure.
  • Jack and boring operation completed.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Thursday, March 30, 2023

  • Hauling operation continues at the Project site.
  • Structural work continues on the Headworks infrastructure.
  • Jack and boring operation has commenced.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Thursday, January 19, 2023

  • Hauling operation continues at the Project site.
  • Structural work continues on the Headworks infractructure.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Thursday, July 28, 2022

  • Hauling operation continues at the Project site.
  • Structural work throughout the site has commenced.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Monday, March 07, 2022

  • Hauling operation continues at the Project site.
  • Existing structures are undergoing demolition.
  • Public Works will continue noise monitoring throughout the duration of the project.
  • In the following weeks, structural work will commence.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Monday, December 20, 2021

  • Hauling operation continues at the Project site, as well as the removal of existing structures.
  • Throughout the duration of the project, continuous air quality monitoring will be conducted. Monthly Air Quality Monitoring Report Summaries can be found in the Resources Section below.

Thursday, September 30, 2021

  • The first Notice to Proceed was issued on May 25, 2021. The contractor completed pre-construction activities (i.e. temporary access road pavement, sound barrier installation, construction fence, and tire wash stations).
  • The second Notice to Proceed was issued on September 21, 2021.
  • The hauling operation is set to begin on Monday, October 4, 2021.
  • Refer to the July 28, 2021 Community Meeting Presentation under the Community Engagement Section for information on the haul routes.
  • Public Works will be conducting air quality monitoring throughout the duration of the of project. The associated reports will be made available in the near future.

Los Angeles County Board of Supervisors adopted the project and its Recirculated Mitigated Negative Declaration on March 9, 2021. Construction of the project is scheduled to begin in August 2021 and last nearly 3 years. Excavated material will be transported to Sunshine Canyon Landfill in Sylmar and Cal-Mat Pit in Sun Valley.

Construction activities will take place from Monday through Friday, between 9 a.m. - 5:30 p.m. Access to residents will not be impacted during construction. Low emission trucks will be used for the transportation of material. LA County will implement measures for noise and dust suppression during construction.

Community Engagement

Past Community Event(s)

Wednesday, July 28, 2021 6:00 PM - 7:30 PM

PACOIMA SPREADING GROUNDS BASIN ENHANCEMENT PROJECT CONSTRUCTION UPDATE (SEE ATTACHED FLYER)

Construction of the Pacoima Spreading Grounds Basin Enhancement Project is scheduled to begin in August 2021 and last nearly 3 years. The project will enhance stormwater capture for local water supply and include:

  • A new bike path along the Pacoima Diversion Channel, between Devonshire Street and Filmore Street to improve neighborhood connectivity.
  • Installation of tubular perimeter fencing.
  • Reconstruction of the basins to increase water conservation capacity.

During this meeting, we will share an update on the project and construction information as well as answer questions. Spanish translation will be available.

Attachments

Resources

Contacts

For construction-related questions, please contact

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

Updated on: 07/01/2024