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Dos Rios Ranch



Dos Rios Ranch is a small piece of a former 250,000-acre Spanish land grant called “El Pescadero” which means “the fisherman." This bit of history highlights the important role the San Joaquin River and its tributaries (such as the Tuolumne River) once played for the Pacific Coast salmon and steelhead trout fisheries. Before the construction of dams, levees, and massive water delivery projects such as the Central Valley Project and the State Water Project, the cool clear waters of the San Joaquin River would run dark with migrating fish each spring and fall – ocean-hardened adults seeking high quality spawning habitat high in the Sierra Nevada. Winter storms and spring snowmelt would flush juveniles back out to sea and the cycle would continue, waxing and waning with annual fluctuations in California’s precipitation patterns. Today, the hard-working waters of the San Joaquin Valley provide little attraction for salmon and steelhead. These waters are muddy and warm, hosting almost no aquatic life, and posing a sincere predation risk for any critter unlucky enough to struggle through this dead zone. The once historic anadromous fish runs of the San Joaquin are now clinging to their existence with annual returns numbering in the dozens. The toll this devastation has had on the local and regional fishing economy cannot be understated.

Since completion of Friant Dam in 1942, the San Joaquin River headwaters have been completely isolated from downstream areas like Dos Rios Ranch through over-allocation of water to fuel breathtaking growth in the agricultural sector. The irrigated desert of the San Joaquin Valley consistently reports 8 of the top 10 agricultural producing counties in the nation. It produces 80% of the world’s almonds, and provides dairy products to countries from South Korea to South Africa. Water exports to the Los Angeles and San Francisco metropolitan areas now threaten not only the native fauna of the once-lush valley, but also the most productive agricultural economy in the world. The communities that once found subsistence and respite along the rivers’ edge now view the river as a commodity, one that drives record home prices and urban sprawl.

In 2006, the U.S. District Court in Sacramento ruled that under California Fish and Game Code Section 5937, river flows released from Friant Dam must be managed to support self-sustaining salmon populations from the mountains to the sea. Future habitat restoration at Dos Rios Ranch will increase the availability of shaded aquatic habitat critical for migrating fish species, in particular the salmon that will benefit from this court-ordered increase in river flows. Restoration of riparian habitat at Dos Rios Ranch will also reduce sediment loading (by slowing flows and providing an opportunity for the mud to settle out of the stream) and provide a source of large in-stream wood which provides cool protected resting areas and supports the aquatic food web for apex fauna, like spring-run salmon.

Conservation successes like the preservation of the Dos Rios Ranch offer a glimmer of hope to those who value the serenity and the natural values of the San Joaquin Valley. The project will provide opportunities for valley residents to visit the river, take their kids fishing, and observe first-hand the recovery of the southern-most anadromous fish run on the Pacific Coast envisioned by the San Joaquin River Restoration Settlement Act of 2009.


The San Joaquin Valley is a vitally important wintering area for Pacific Flyway migratory birds. Providing a migration highway for waterfowl and small songbirds, wetlands and natural areas in this region support an astonishing global phenomenon in which the change of seasons coupled with a pulse of moisture from winter precipitation stimulates massive migrations across the face of the planet from the southern tip of Chile to the northern arctic tundra. During peak migration, more than 1.5 million ducks and geese, and over 250,000 shorebirds use the valley for foraging and resting. During summer months, Neo-tropical migratory songbirds rely upon San Joaquin Valley floodplain habitats for nesting and stopovers.

Floodplain wetlands, pastures, and grain fields in the northern San Joaquin Valley provide important habitat for Snow, Ross’s, and Canada geese, gadwalls, teals, wigeons, pintails, cranes, avocets, stilts and ibis. They host nesting warblers, flycatchers, grosbeaks and vireos. Year-round, the floodplain habitats of the San Joaquin Valley host egrets, herons, blackbirds, sparrows, wrens, meadowlarks, owls, hawks, quail, and pheasant.

The North American Waterfowl Management Plan has identified the Central Valley as an “Area of Continental Significance to North American Ducks, Geese and Swans” due to its importance as a major migratory and wintering area along the Pacific Flyway. Frequent visitors to this region include: western Canada goose, Aleutian cackling goose, lesser snow goose, Ross’ goose, gadwall, green-winged teal, northern shoveler, cinnamon teal, ruddy duck, common goldeneye and bufflehead. Occasionally, black brant, red-breasted goose, Barrow’s goldeneye, blue-winged teal, Eurasian wigeon, Mandarin duck, fulvous whistling duck and hooded merganser have been seen.

Threatened and Endangered Species

Riparian and wetland habitats support the largest diversity of wildlife of any habitat type in California. The San Joaquin Valley – about half the size of South America’s Pantanal, once hosted marshlands and forests so treacherous that early explorers could not cross from the Sierras to the Coast except at the very northern and southern tips of the valley. Large herds of Tule Elk and pronghorn antelope roamed the marsh, grazing off the cattails and grasses, and providing meals for wandering grizzly bears. The extent of the human-induced destruction of California’s rainforest in the last 150 years has left only 5% of habitats intact. With this loss, came the loss of all of the Valley’s megafauna – you’d be hard pressed to find a deer along the river in western Stanislaus County today – and a massive reduction in the numbers of birds and fish that migrate through with the changing seasons.

Least Bell’s vireo is a small summer migrant that was once abundant in the riverside forests of the San Joaquin Valley. Naturalists in the early 1900’s reported common sightings of this tiny songbird. Since the completion of Friant Dam, this bird had not been seen in the San Joaquin Valley until the summer of 2005, when it was observed nesting in an arroyo willow that had been planted and cared for by River Partners, a Central Valley-based non-profit dedicated to the restoration of riverside habitats for the benefit of people and the environment. The return of Least Bell’s vireo to the Central Valley signifies a success for conservation in that we’ve validated that our methods of habitat restoration can work, but there is still a long way to go. The Dos Rios Ranch acquisition represents an opportunity to expand upon the largest contiguous riparian habitat restoration initiative in California – with partners from the agricultural sector, NGOs, academia and every federal and state resource management agency in California partnering to find novel habitat management approaches that net real wildlife recovery results. Projects like this serve as models for the type of action it will take to bring species back from the brink of extinction while maintaining and improving quality of life for area communities.

Climate Change

With rising global temperatures, riparian habitat corridors will become increasingly important for species conservation. The Grinnell Resurvey Project (Moritz 2007) has identified a 100-year trend in species diversity and abundance along an elevational transect from the San Joaquin Valley over the crest of the Sierra Nevada. By revisiting wildlife diversity and abundance transects first surveyed in the early 1900’s, researchers have discovered that the habitat range of several common valley residents has expanded in elevation substantially. Additionally, species typical of the higher elevations have seen significant retractions in the habitat range to even higher elevations. These results suggest that changes in habitat conditions over the last century have favored species movement to higher elevations in the Sierras. East-west migration corridors in California’s Central Valley may play a vital role in species survival as habitat conditions in the lower elevations become less favorable. The Tuolumne River hosts a potentially wide riparian corridor that runs east to west straddling the valley and the foothills. Preservation and restoration of this area will provide lasting and significant benefits to wildlife as a movement corridor, especially in the face of global climate change.

Economic Stimulus

The Dos Rios Ranch Project represents an unprecedented investment of state and federal funding in the San Joaquin Valley. Through dogged perseverance and strategic support from a State-wide conservation network, River Partners and the Tuolumne River Trust were able to deliver more dollars to Stanislaus County focused on habitat conservation with this one project than in the last 5 years combined. This investment results in direct job creation, support services and patronage of area businesses and vendors, and stimulates the growth of industries that cannot be exported: riverside recreation and sport, wildlife restoration and management, environmental education, eco-tourism, and even improved agricultural efficiency. This project will retire agricultural water diversions leaving more water to percolate into the strained aquifer and more water flowing downstream to the communities and farmers who draw river water for domestic and agricultural uses.

Strategic Flood Management

The San Joaquin River provides a conveyance channel for massive flooding that results from the San Joaquin Valley’s network of dams and bypasses becoming overwhelmed by uncharacteristic storms. This critical public safety function has shifted water planners’ view of the river from one of a vibrant living system to more of a trapezoidal channel optimized for flow out to the San Francisco Bay – contributing further to the dire situation for wildlife of the valley. In 2012, California’s Department of Water Resources completed a massive effort to take a comprehensive look at the function of our flood management system and find ways to link the ecological and engineering solutions that are needed to provide reliable flood protection for growing urban areas like Stockton while enhancing the value of the flood system for wildlife, water quality, and people. The FloodSAFE California Initiative, and the Central Valley Flood Protection Plan envision multi-benefit flood control projects in which the dynamics of a flood fight can synergistically stimulate riverside wildlife and vegetation.

Dos Rios Ranch and the adjacent San Joaquin River National Wildlife Refuge stand as a landscape-scale model of such strategic and multi-benefit flood-control projects. By repurposing the floodprone lands behind the levees to act as high quality floodplain habitat for threatened and endangered wildlife AND transient floodwater storage basins during massive flood years, these projects find the sweet spot between two historically competing land uses. Since 2002, River Partners, the USFWS, DWR, and a host of other technical experts, engineers and conservation partners have designed and installed levee breaches, constructed wetland basins, elevated refugia for terrestrial species and vegetation patterns that safely convey floodwaters in a strategic way to optimize the flood protection benefits of the largest contiguous riparian habitat restoration initiative in California at the confluence of the San Joaquin River and its largest tributary. Such multi-benefit projects provide opportunities to link public benefit programs that focus on habitat enhancement and public safety to net large results with small price-tags. Such efforts are demonstrations of the ingenuity and collaboration that will be the hallmark of effective solutions targeting the next 100 years of California’s epic water management conflicts.

Leveraged Partnerships

Dos Rios Ranch is the keystone of the Lower Tuolumne River Parkway, a mosaic of public and private restoration/ enhancement projects from La Grange Dam to the Tuolumne River’s confluence with the San Joaquin River that provide habitat and public use opportunities and are compatible with existing private interests. The Tuolumne River Coalition is a local collaborative effort that acts as a forum for coordination of projects affecting habitat, recreation, and flood control on the lower Tuolumne River. The habitat value and floodwater attenuation value of the Dos Rios Ranch makes a very significant contribution toward realizing the vision articulated in the Lower Tuolumne River Parkway – A Framework for the Future. This plan has been adopted by NGOs, as well as local, state and federal agencies as a guide to improving floodwater conveyance, habitat and recreational opportunities on the lower Tuolumne River.