Science for Restoring the Los Angeles River | Watersheds of Los Angeles and Ventura Counties

The LA River

Arroyo Seco above Pasadena. Photo by S. Drill

The 51 mile long Los Angeles River receives rain and snowmelt from the San Gabriel and Santa Monica Mountains as well as the plains of the Los Angeles basin. It flows through a national forest, a national monument, and a national park, as well as through 14 cities and the unincorporated area of Los Angeles County. Thirty-one miles of the river flow through some of the densest urban areas in the City of Los Angeles. Finally, it reaches the sea in Long Beach, draining into the San Pedro Bay. The upper reaches in Arroyo Seco and Tujunga Wash support riparian aspen and willow forests, while much of the middle and lower river exists only in concrete channels. Even here, there are stretches with a natural bottom in Sepulveda Basin, the Glendale Narrows, and along Willow Street in Long Beach where fish, birds, and people spend time in urban nature.

Fishing with volunteer anglers in the LA River Estuary. Photo by S. Drill

Cooperative Extension Advisor Dr. Sabrina Drill conducts research on aquatic habitat, the fish fauna, fishing by neighboring community members, and how climate change is impacting temperature and flow in the river. She uses this information to guide restoration of this important urban ecosystem.

LA River Master Plan

The County of Los Angeles' LA River Master Plan will play a significant role in determining the future of the river.

Fish and Habitat Surveys

We want to hear from you! Because it's difficult to use traditional nets in the urban parts of the river, we rely on collaborations with volunteer anglers. We need your observations to get a robust picture of the the fish community in the river. Please share your catch, or your observations, at our iNaturalist project, Fish of the Los Angeles River/Pesces del Rio de Los Angeles, http://bit.ly/LARFish.

Researchers from UCCE, Friends of the Los Angeles River, the Resource Conservation District of the Santa Monica Mountains, Aquarium of the Pacific, and CalState LA have collaborated since 2007 to study the fish community and fish habitat in the river.