09/10/2026
In May, the City of Pomona began construction of the Pedley Spreading Grounds Enhancements Project at its facilities located off Longwood Avenue in Claremont. The Pedley Spreading Grounds site, located adjacent to Chaparral Park and Chaparral Elementary School, is owned by the City of Pomona.
Once completed, this project will improve the ability to capture local stormwater runoff and percolate it into the ground, recharging regional groundwater basins that serve as a critical source of drinking water for our community. Key improvements include regrading and enhancing existing stormwater infiltration basins to maximize their capacity, along with modifications to the storm drain system near Base Line Road and Mills Avenue to direct additional stormwater flows to the spreading grounds. The project will also install a new water quality treatment structure to reduce pollutant loading before stormwater enters the basins.
Nearby, the project includes the construction of parklet improvements at Chaparral Park featuring new landscaping, a public viewing area overlooking the spreading grounds, and educational signage to help residents learn about the local water supply system. This project element came as a request from Claremont residents and Chaparral Elementary School during the project’s outreach process. This phase of the project has recently commenced, and the work being performed at the parklet is limited to the parcel owned by the City of Pomona, as currently delineated by a fence, and all work is being conducted per plans. The plans specify that the Contractor protect the existing trees in place, and the City of Claremont's arborist has been on-site to evaluate the trees adjacent to the work area. Weather permitting, the City of Pomona estimates that this phase of their project will be completed by the end of November.
The project is funded in part through the Los Angeles County Safe, Clean Water Program, made possible by voter-approved Measure W.
In addition, the public can contact the City’s Engineering Division at (909) 399-5465 with questions regarding this project.
Project details may be found at pomonaca.gov/PSGPonds.
If you have any questions or to report construction-related issues, please contact:
pomonaca.gov/PSGPonds
[email protected]
