Sears Point Wetland Restoration Project on San Pablo Bay
On Sunday October 25, after 10 years of planning and $18 million dollars raised, Sonoma Land Trust breached a levee along the north edge of San Francisco Bay at Sears Point Ranch. The 285-foot-wide breach allowed salt water to fill a recently constructed 1,000-acre tidal marsh basin for the first time in over a century. The area - located midway along Highway 37 between the towns of Novato and Mare Island - filled in with Bay water quickly, but is expected to take decades to evolve into established tidal marsh such as it was before being diked off from the bay.
This two-minute video by Land Trust staffer Corby Hines (with drone operators Eric Carpenter and Michael Heumann) provides an up-close glimpse of the breach event.
During the design phase, the SFBJV offered a design review process with funding from the State Coastal Conservancy. This enabled four area experts in Bay ecology, hydrology, geomorphology and tidal modeling along with staff from the San Pablo Bay National Wildlife Refuge to assist with addressing key design elements that ultimately impacted the final outcome.
A = Nearly 1,000 acres of future tidal marsh connected to the earlier Sonoma Baylands restoration site in the background;
B = Separated from the tidal marsh by the railroad track and the new habitat levee, this area will be a focus for seasonal wetland enhancement; and
C = Sears Point uplands, nearly 1,000 acres of grasslands, seasonal wetlands and riparian drainages. Photo by Robert Janover.
Once established, the new tidal marsh will enhance the entire bay ecosystem, and like all tidal marshes will offer significant benefits such as the provision of key habitat for endangered and native species, the capture and sequestering of carbon, the filtration of pollutants, and protection of our infrastructure from the rising seas and storm surges expected as a result of climate change. Additionally, a new 2.5-mile-long section of the San Francisco Bay Trail on top of the new levee, will provide some of the best access to the Bay in Sonoma County. The trail, and a kayak ramp, will open to the public by early 2016.
This restoration has benefited by lessons learned from previous projects, as well as from nature itself, and incorporates several innovations to reduce the cost of the overall project and increase the pace at which the marsh is expected to grow.
On June 6, Joint Venture partners gathered to celebrate the start of construction on the 2,327 acre property known as Sears Point. After nearly 10 years of planning and raising close to 18 million dollars, Sonoma Land Trust and project partner Ducks Unlimited will prepare approximately 960 acres of diked agricultural baylands for the reintroduction of tidal action. The land along Highway 37 almost became a casino resort, but instead was purchased by Sonoma Land Trust in 2005 and soon enough, after more than a century of isolation, it will become reconnected to San Pablo Bay.
More than 85% of SF Bay's historic tidal wetlands were lost beginning in the late 1800s when extensive diking of historic marshes took place and land was "reclaimed" for farming oat hay and wheat, and grazing dairy cows, to supply the growing city of SF. The Sears Point project will assist in turning back this loss by reintroducing the tides and, as a result, restoring critical habitats for wildlife, protecting against sea level rise, improving water quality and expanding the San Pablo Bay National Wildlife Refuge.
An unintended consequence of reclaiming the marshes was that the peaty soils, exposed after millennia underwater, decomposed and caused the land to sink. Now below sea level and with sea levels rising, SLT, DU and others have incorporated innovative designs features to accrete sediment, including marsh mounds scattered randomly and purposefully throughout the future tidal basin which will block wind erosion and attract sediment for plants to establish themselves. A new 2.5 mile levee needed to protect Highway 37 and the railroad will be built in a way such as to also create habitat and refuge for marsh wildlife. According to Juilan Meisler, SLT Baylands program manager, "the site will [also] become Sonoma County's premier access point to the Bay" with the addition of 3.5 miles of new trails, including a 2.5 mile segment of the San Francisco Bay Trail.
For more information about the project follow this link.
Bay Area Media coverage of the event: