RESTORATION CASE STUDY

Traditional stormwater management in Los Angeles rushes rainfall into storm drains and concrete channels to minimize flood risk. Rainfall that would otherwise replenish the water table flows into the Pacific Ocean. At AFC’s Rosemont Preserve, we set out to capture as much rainfall as possible before it reaches nearby debris basins and concrete channels. Working with Crescenta Valley Water District and the County of L.A., we designed and built a 600 square foot bioswale to intercept runoff from Goss Canyon and the surrounding streets.

BIOSWALE

A shallow depression in the landscape that collects water. As it soaks through the soil, sediments and pollutants are filtered out and aquifers deep in the earth are recharged. 

The idea was simple, but the process was not! Water capture projects are difficult to pursue: too often, they get stalled or abandoned because of complex water rights, an onerous permitting process, high construction costs, and other bureaucratic obstacles. But we overcame these obstacles by collaborating with private and public partners and doing out-of-the-box thinking.

BEFORE
DURING
AFTER

Half of the water used by residents in La Crescenta comes from the Verdugo Groundwater Basin. Rosemont’s bioswale replenishes it while supporting the local ecosystem. 

Mule deer doe and fawns, grooming at Rosemont Preserve, La Crescenta, CA, Photo by Althea Edwards
Harvester ants (Pogonomyrmex californicus) moving an elderberry fruit (Sambucus mexicana) at Rosemont Preserve, La Crescenta, CA. Photo by Althea Edwards
Red-tailed Hawk (Buteo jamaicensis) over Rosemont Preserve, La Crescenta, California. Photo by Althea Edwards.
Mulefat (Baccharis salicifolia) seeds at Rosemont Preserve, La Crescenta, CA. Photo by Althea Edwards.

Bioswales can be scaled down for backyards and expanded into larger-scale infrastructure. This project at Rosemont demonstrates that we don’t need to choose between conserving land for wildlife and improving infrastructure: one can be thoughtfully designed to strengthen the other.

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Projects like this take years of planning, partnerships, hands-on preparation, and ongoing stewardship. A donation from you today ensures we can continue to protect habitat and make our region more resilient.