Eastern view of the Santa Clara River.
Santa Clara River Eastern view of the Santa Clara River. © Melinda Kelley

Places We Protect

Santa Clara River


Partnering with farmers along the Santa Clara River is our best chance for protecting critical river habitat in Southern California.

The Nature Conservancy has made major strides in protecting one of the most important and intact river systems in Southern California. The Santa Clara River is a vital source of drinking water for the local community, as well as a key resource for many prosperous farms. It also offers some of the last riverside and freshwater habitat for wildlife in the bustling Los Angeles-Ventura region.


Starting high up in the Angeles National Forest in Los Angeles County, flowing down into Ventura County and into the estuary at McGrath State Beach, the Santa Clara River and its tributaries are surrounded by more than 12 million people. As the population soars, urban sprawl bears down on the river and its watershed, threatening:

  • The supply and quality of the region’s freshwater, including precious groundwater reservoirs that are fed by the river;

  • The farmers whose fields and groves line the river and surrounding lands, making a healthy contribution to the local economy and regional identity; and

  • The plants and animals within the watershed that rely on the extensive habitat of the river system, including a staggering 16 species within one mile of the mainstem of the river that are federally and/or state listed as threatened or endangered.

Adding to the pressure, 95 percent of Southern California’s river and wetland habitat has already been lost. In fact, this is one of the last rivers in Southern California that remains relatively natural. Other major rivers in the region, including the Santa Ana, San Gabriel and Los Angeles, have been reduced from lush, flowing rivers to largely concrete channels with very little wildlife habitat.

Investing in Farms and Wildlife

Much of our work along the river focuses on habitat restoration through invasive species removal. But equally important is preserving farmland within the floodplain to maintain the river’s wild state.


When TNC launched the Santa Clara River project in 1999, Southern California was at the peak of one of its largest real-estate booms, with building plans being approved as fast as they were proposed. It became clear that protecting the 84-mile-long river and its numerous tributaries would require a buffer zone between the river and the developed areas. Threatened farmland could provide that buffer.

We began partnering with the farmers, open-space advocates and county agencies of the region to develop innovative land-use and flood-control policies that protected the farmers’ livelihoods. Together, we explored ecologically compatible farming techniques that safeguarded the habitat and water supply and would prevent the river from suffering the channelized, concrete-lined fate of its sister rivers.

The Nature Conservancy has played a large role in protecting the Santa Clara River and its tributaries in Southern California.
Santa Clara River Farmland The Nature Conservancy has played a large role in protecting the Santa Clara River and its tributaries in Southern California. © Melinda Kelley

To date, TNC has protected a total of 4,156 acres—or approximately 21 miles of riverside habitat—on the Santa Clara River. We have purchased easements that cover 551 acres of farmland and floodplain habitat adjacent to the river, encouraging farmers to continue farming, and permanently preventing suburban development.

This land protection provides wildlife habitat and improves the health of the river and its floodplain. The farms on the floodplain allow the river’s natural hydrologic process to continue by absorbing flows during periods of flooding, which provides natural downstream flood protection to cities and towns that would otherwise have to rely on levees to keep the river at bay. The avoided cost of flood damage is estimated to be over $1 billion and there’s no need to build or maintain a levee when nature does the job for us more effectively and affordably

Critical Habitat

The river and its floodplain provide shelter and food for endangered fish and birds, along with coyotes, bobcats, rabbits, lizards, mountain lions and black bears.


TNC is actively engaging with the public at the Santa Clara River, by providing public outreach and education opportunities through guided naturalist tours, volunteer workdays, and formal research partnerships. We host two monthly guided hikes led by an experienced naturalist to help members of the community learn about and appreciate the natural treasures of this landscape. Our vision is to open much of this conserved and restored habitat to the public to improve the quality of life and sense of connection to nature for local communities.


Restoring the river includes working with our partners to find smarter ways to combat the tremendous problems brought on by invasive weeds, like Arundo donax, a head-high grass that chokes out the native plants that hundreds of animals depend on for food and shelter.

We are removing extensive stands of Arundo to allow the native vegetation to return and provide habitat for nesting species, including two federally endangered songbirds, the least Bell’s vireo and the southwestern willow flycatcher.

Native animals are also benefiting from our efforts. In one of the nation’s most ambitious carnivore studies, our partner, the National Park Service, is studying how large predators like bobcats and mountain lions cope with urban development. The results will help us identify ways to protect viable habitats for these original native residents given the development that is bound to occur with the human population explosion.

Santa Clara River snaking through vegetation, with exotic species in the foreground.
Invasive Weeds Santa Clara River snaking through vegetation, with exotic species in the foreground. © Barbara Wampole


Groundwater is found deep in underground reservoirs. These vital reserves of water account for one-third of the state's water supply, and double that in drought years. While we’ve been treating it like an endless resource, the state has recently passed a new law that will cap groundwater use. The Sustainable Groundwater Management Act (SGMA) calls for state-level actions to make groundwater use more sustainable, including projects like floodplain restoration that would help reduce flood risk, create habitat for migratory birds, and replenish groundwater.

In the Santa Clara River watershed, TNC worked with the Fox Canyon Groundwater Management Agency to draft a plan for sustainable groundwater use, a key part of SGMA implementation. We provided science and data  to ensure that nature’s water needs were reflected in the plan. The agency aims to finalize the plan in 2019, and once completed, TNC will use this as a model to influence dozens of other SGMA plans in the state.

Research Partners

Creating access for researchers allows us to inform and continuously improve our management practices based on the latest science. Academic research partners include universities, consultants, and local, state and federal scientists.


Today, we have protected one-third of the river that winds through Ventura County, and we’re now taking on the Los Angeles County portion of the river to accomplish our goal of protecting close to 30,000 acres of river in the midst of one of the world’s fastest growing metropolises.