After 82 years, the 169-acre Pacoima Spreading Grounds (PSG) in Mission Hills and Arleta is scheduled for an upgrade.
As one of four spreading grounds in the San Fernando Valley, this unassuming sea of dry dusty basins in the middle of a quiet residential area plays an important role in replenishing our city’s groundwater supply.
The LA County Flood Control District (LACFCD) manages the PSG Improvement Project scheduled to begin in the summer of 2016 funded by a $3 million grant from Prop 84 with the rest of the construction costs split 50/50 by the LA County Department of Public Works and the LA Department of Water and Power.
After the $35 million PSG Improvement Project is completed it should have double the water storage capacity and almost double the water percolation rate. When the storms finally do arrive this extra capture capacity will add a much needed bonus as 11% of the city’s total water supply over the last ten years has come from groundwater.
It comes at a higher price than just the $35 million. Those who live next to and near the spreading grounds, use the adjacent parks, walk the Nature Parkway on Devonshire St or attend Telfair Elementary will experience in some degree or another two years of very unhealthy diesel exhaust, dangerous dust particulates, noise, vibrations and likely traffic congestion.
The project will be in two stages: One, replacing the radial gate that lets storm water into the spreading grounds, with a rubber dam and replacing the open channel with two reinforced concrete pipes opening up an area to use as a possible green space.
Two, excavating up to 30 feet down, sifting out clay and sediment and then placing the remaining more permeable sandy soil back into six newly combined basins at a depth of around 12 feet leaving about 1.24 million cubic yards of material to be trucked out of the PSG.
The current plan is to use up to 240 diesel trucks a day to transport the material to gravel pits in Sun Valley. They would exit onto Devonshire following a route via the 5 freeway at Paxton St or 40% of the time continue down Paxton turning right on San Fernando Rd.
The Initial Study on the Pacoima Spreading Grounds Improvement Project is due out October 2014. Check the PSGProject.info site for more in-depth information on the project and a link to the study when posted. Initial Studies are open for a minimum 45-day commenting period.
Other Los Angeles County Flood Control District managed projects in the North Valley include the Pacoima Reservoir Sediment Removal Project and the Tujunga Spreading Grounds Enhancement Project.
Editors’ note: EizabethMarx is a member of the Mission Hills Community Action Group, “Making a difference one project at a time”as well as Editor of missionhills91345.com a blog with occasional tidbits of local news. She believes a connected community is an empowered community.

The Pacoima Spreading Grounds, a Los Angeles County Flood Control District Water Conservation Facility, has 12 shallow spreading basins with a 550 acre feet spreading capacity at a 65 cfs percolation rate. The source of its water comes from the Pacoima Reservoir, the Lopez Flood Control Basin, East Canyon, the Pacoima Wash and untreated imported water from the
In the not too distant future the LADWP plans to pipe reclaimed, Title 22 water from an as yet to be built facility at Ronald C.Tillman Water Reclamation Plant to recharge at the Pacoima Spreading Grounds. The Initial Study on the project was in September 2013.