John Cain met us at Brannan Island. He is the director of restoration programs for the Natural Heritage Institute (in the 1990s he had worked for the Mono Lake Committee). While Janet and I toured in John’s car, the boats shifted to the southwest end of Sherman Island. Our road ran beside the Sacramento River, the major river artery of the northern half of the state. Massive wind turbines decorated the hills beyond the channel.

John told us that groundwater pumps run constantly in the Delta to keep fields dry enough to grow crops. Farm soils are constantly subsiding because the peat soil, exposed to air, is oxidizing and losing one to two inches of soil volume each year.

We stopped on Twitchell Island, 12 feet below sea level, where native tules and cattails were growing on several acres of ponds. John reached into the water and came up with a handful of dripping black mud. “The rate of tule muck accumulation is about two inches per year. We’re reversing subsidence--actually building up this island. These islands have become a substantial source of atmospheric CO2, so this converts a carbon source to a sink. We’re hoping to do this on a much larger scale.”

We mulled over “carbon-capture farming” as we drove to the south end of the island to see an experimental “green levee” covered with lush growth. Engineers prefer that levees be bare so they can see signs of failure, but during a recent flood event, John said, “when people thought the standard levee was going to go, everyone took shelter behind this levee armored with vegetation.”

To reach the Antioch Bridge and the south shore of the river channel, we drove across Sherman Island, 11,000 acres of farmland at the western margin of the Delta that are theoretically protected by levees. However, those levees were built on sand foundations that may undergo liquefaction during a large earthquake.

Across the bridge are the communities of Antioch and Oakley, with shopping malls, housing tracts, and crowded highways. On a dairy farm near Dutch Slough, a few miles east of Oakley, construction of 4,500 homes had been planned, but the farmer was persuaded instead to sell the 1,200 acres to the State, a purchase made with CalFed Bay-Delta Accord water bond funds. This Dutch Slough project, conceived by John for the Natural Heritage Institute, includes the Coastal Conservancy, California Bay-Delta Authority, Department of Water Resources, and City of Oakley as partners, and will become the largest freshwater tidal marsh restoration project in the Delta.

We walked atop a levee, trying to visualize the pasture as tule wetlands. “Come back in ten or 20 years,” John told us, “and you should see valley oaks and sycamores and walnut trees grading out into grasslands and tidal marsh.” In time, the restored wetlands should support juvenile salmon pausing to feed and grow before they finish their own treks from the mountains out to the sea.

Our final destination with John was a subdivision in Oakley built below sea level. The levee there meets 100-year FEMA standards, so homeowners are not required to buy flood insurance. With climate models forecasting a possible four-foot sea level rise by the end of the century, however, such faith in levees seems a recipe for disaster.

Strait to the Bay
The following morning, the 14th day of our trek, the tide was very low, the Bay nearly flat, the weather sunny and calm--perfect for paddling the 9.5 miles to Vallejo in handmade kayaks John Knott and David Martin had brought on the sailboat. We were rocked by the wakes of several massive ships far out in the deep-water channel. Cars looked tiny on the freeway spans of the bridge far overhead. As we paddled beneath them, I whooped out loud with exhilaration. It was a thrill to kayak under the Carquinez Strait bridges into San Pablo Bay, reaching that destination along with vital flowing water that had originated in the Sierra Nevada high country.

On the far side of the strait we rounded a breakwater and entered Mare Strait. We continued to the Vallejo Municipal Marina, where the sailboats caught up with us. There we took Marc Holmes on board. He is the bay restoration program director for the Bay Institute. Marc guided us a few miles up the Napa River to former Cargill salt ponds now being restored (at 38º09N, ten miles north of our latitude line--the farthest we strayed on the trip). Originally there were 196,000 acres of tidal marshes from Suisun Marsh out through San Francisco Bay. Eighty-six percent of that is gone. The opportunities for coastal wetlands restoration in the Napa-Sonoma marshes are enormous.

As we motored upriver, Marc pointed toward houses lining the northeast shoreline. “None of those residences could be permitted today, because they’re built in the tidal margins of the Bay. The San Francisco Bay Conservation and Development Commission was established in 1965 to regulate bayfront development and protect the Bay. By then, one-third of the Bay had been filled or diked or drained.”

Everyone transferred to Marty’s catamaran to motor into the salt pond complex, now managed by the Coastal Conservancy. Tidal marsh had been converted there in the mid-1870s to grazing land and later to duck hunting clubs. The Leslie Salt company bought the properties and later sold them to Cargill. The salt pond complex circulated Bay water through 12 increasingly concentrated 1,000-acre ponds.

“This cordgrass that you see is new growth since the levees were breached 18 months ago,” Marc said. “None had been in here in 100 years or more. Their seeds traveled naturally on the tide. I’m stunned to see that much cordgrass in so little time.”

The rest of the food chain was returning too, including invertebrates and birds. “And we haven’t even talked about fish,” Marc added. He reiterated what we’d heard from John Cain about the importance of wetlands to juvenile salmon. “And this is the farthest west habitat for delta smelt,” he added. The endangered delta smelt is at the center of controversy over diversion cutbacks, because aqueduct pumps chew up so many of the tiny fish. “This is so great; you’re seeing it right at the beginning,” Marc exulted. “Come back here in five years and the cordgrass lines will extend across the pond.”