In a dramatic moment, on Jan. 6 work crews breached the levee that has kept Cullinan Ranch, 1,200 acres of diked wetlands in the Napa River Delta, unnaturally dry for more than a century. Save The Bay Executive Director David Lewis, Habitat Restoration Director Donna Ball, and I joined representatives from the U.S. Fish & Wildlife Service, Ducks Unlimited, and other partners to celebrate the culmination of a decades-long effort to restore the site. What’s next? Project designers expect near-immediate resurgence of waterfowl and shorebirds, and with tidal waters already beginning to carry natural sediment to the site, native plants will eventually take root and re-establish habitat for our Bay’s wild creatures. Read the full story of Cullinan Ranch below. -Cyril Manning
Cullinan Ranch is a 1500-acre parcel of former tidal marsh at the top of San Pablo Bay, part of the Napa River Delta. As you can see from the map at right, it is an important puzzle piece in the sprawling restoration of the whole northern part of San Francisco Bay, work that has been described as an “aquatic renaissance… turning back the clock 150 years and transforming the area between Vallejo and Sonoma Raceway.”
Like nearly all the tidal marsh around San Francisco Bay, Cullinan was diked off in the 1880s to be farmland (see this nice timeline covering the history of the site). A proposed residential marina community nearly destroyed the area 25 years ago, but the proposal was defeated in 1987.
After the site was proposed for development, Save The Bay joined with local residents in Vallejo and hired Shute, Mihaly & Weinberger to sue over the “Egret Bay” development, which proposed thousands of homes on this restorable site, below sea level. Getting involved in the battle was a first for Save The Bay – actually advocating for restoration of a diked former wetland, not just against new fill and inappropriate shoreline development.
That successful lawsuit, along with the denial of construction permits by BCDC and the US Army Corps of Engineers, put a stop to Egret Bay, making possible Cullinan’s purchase by the US Fish & Wildlife Service in 1989, and protection as a wildlife refuge. Now, this site — one and a half times the size of San Francisco’s Golden Gate Park — is being returned to marsh as part of the West Coast’s largest wetland restoration effort.
After the site was first diked off for grazing and oat hay, the marshland dried out and compacted like a sponge, and now lies six to nine feet below sea level. When the levees are opened later this year, the site will initially be open water and mud flats, then sediment from the Napa River and Bay will eventually build up, so that tidal marsh vegetation can begin to grow back.
Another key challenge is restoring the property while protecting the critical infrastructure that runs through and around it. A levee to protect Highway 37 from the new tidal action is the single most expensive element in the $16 million wetland restoration project. The SF Bay Don Edwards and San Pablo Bay Wildlife Refuges are crisscrossed by much of the region’s critical transportation, electrical and water supply infrastructure, which add expensive urban complexities that are not usually a part of refuge restoration projects.
As local scientists, communities, and conservationists work together to bring us closer to the 100,000 acres of tidal marsh needed for a healthy Bay, sites like Cullinan Ranch serve as a valuable model and inspiration. They show we can succeed in preventing projects like Cargill’s proposal to build homes in a Redwood City salt pond, and instead ensure that site is restored along with other ponds, together restoring the Bay for people and wildlife.