NAPA -- The Carneros region in southern Napa and Sonoma counties has been known for years for chardonnays, pinot noirs and merlots.
But as the grapes hang plump on the vines awaiting the autumn harvest, this area along the northern shores of San Francisco Bay is growing a new bounty: huge numbers of egrets, herons, ducks, salmon, Dungeness crabs and other wildlife, all returning to a vast network of newly created marshes and wetlands.
Construction crews and biologists are in the final stretch of a 20-year project to restore 11,250 acres of former industrial salt ponds back to a natural landscape. The aquatic renaissance is already the largest wetlands restoration project ever completed in the Bay Area, turning back the clock 150 years and transforming the area between Vallejo and Sonoma Raceway, despite little public awareness because of the distance from the Bay Area's large cities.
"It's a stunning achievement," said Marc Holmes, program director with the Bay Institute, an environmental group in San Francisco. "It's a phenomenal ecological restoration, one of the most important coastal wetlands projects ever done in the United States."
The restoration -- encompassing an area as big as 8,500 football fields -- is also offering a road map for similar projects now underway in the East Bay and Silicon Valley, particularly the massive restoration of 15,100 acres of former Cargill Salt ponds that extend from Hayward to San Jose to Redwood City.
During a recent afternoon, fishermen in boats motored through parts of the new Napa-Sonoma marshes that look like the Florida Everglades, past flocks of ducks, thick grasses and even the occasional harbor seal. Only a decade ago the area was a dry, desolate expanse of mud caked with white salt crystals.
On Friday morning, a group of local political leaders, nonprofit groups and government agencies plan to meet at the Napa-Sonoma marsh area to commemorate one of the last steps in the restoration. They'll mark the completion of a 3.4-mile pipeline to connect the Sonoma Valley County Sanitation District treatment plant with the marsh complex.
The $10 million pipeline will take up to 550 million gallons a year of treated wastewater to two former salt ponds, where it will dilute a highly saline byproduct of salt-making called bittern, so it can be slowly released to the bay.
"We are bringing back the bay," said Grant Davis, general manager of the Sonoma County Water Agency, which oversaw the pipeline construction. "This is called the Bay Area for a reason. The bay is what defines us."
After the bittern has been diluted, the recycled water will be used for growing grapes in the Carneros region, decreasing farmers' reliance on pumping groundwater.
Since the Gold Rush of 1849, San Francisco Bay has shrunk by a third, as people diked, dredged and filled its waters to create hay fields, housing subdivisions like Foster City, even airport runways. The rampant filling largely stopped in the 1970s, with the advent of modern environmental laws such as the federal Clean Water Act.
Since the 1990s, biologists, environmental groups and government agencies have been restoring wetlands around the bay, slowly pushing it back into its historic footprint. The new wetlands not only expand wildlife and public recreation, they also offer a buffer to reduce flooding as sea levels continue to rise because of global warming, scientists say.
And unlike other environmental restoration projects -- such as replanting a clear-cut redwood forest, which can take 100 years or more to come to fruition -- the payoff with wetland restoration begins almost immediately.
Once earthen levees are breached, bay waters thick with fish, crabs, plant seeds and other life come pouring in, which in turn draw everything from steelhead trout to avocets to snowy egrets looking for a meal.
"Once you open these areas to the tides, Mother Nature takes care of it," said Amy Hutzel, program manager with the state Coastal Conservancy, a government agency that oversaw the marsh restoration. "The sediment, the plants and eventually the animals come back really quickly."
The Napa-Sonoma marsh area was part of the bay until the 1860s, when farmers began diking and filling it. In fact, the word "Carneros" is Spanish for "the ram," a reference to the sheepherders and dairy farms of the 1800s. By the 1950s, salt companies began building huge salt evaporation ponds, cultivating salt for food, road de-icing and other uses.
Everything changed in 1994, when the previous owner, Cargill Salt, sold the property to the state for $10 million. Much of the money came from a $10.8 million court settlement paid by Shell Oil to compensate for a 1988 oil spill it caused in Carquinez Strait.
Crews working on the North Bay Cargill salt ponds restoration ran into numerous setbacks, including funding shortfalls and not knowing how to stop the ponds from making salt at first.
Eventually the whole project, which will cost roughly $40 million, was funded through state and federal money, including bond funds.
Agencies that worked on the project, including the Army Corps of Engineers, the Coastal Conservancy and the U.S. Geological Survey, learned lessons that are helping with other Cargill restoration projects further south.
For now, outdoor lovers, fishermen, duck hunters and the project planners are reveling in their newfound creation. Striped bass, endangered shorebirds and even bat rays are back.
"What's the saying: If you build it, they will come?" said Larry Wyckoff, a biologist with the state Department of Fish and Wildlife, which owns the site. "Well, that's what's happening."
Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/PaulRogersSJMN
For information about how to visit the Napa-Sonoma marsh area, go to www.dfg.ca.gov/lands/wa/region3/nsmwa.