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    Sunrise over Vallejo and Mt. Diablo as viewed from Cullinan Ranch
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    American Avocets feed in shallow tidal waters
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    Recently restored tidal marsh in the San Francisco Bay
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    Sandpipers take flight in a tidal lagoon
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    A quiet slough in the Napa Sonoma Marsh
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    Tidal marsh transitions to open water in the San Pablo Bay NWR



7/14/14 - Dredge material from the Mare Island dry docks is being placed inside Cullinan Ranch...

7/10/14 - Phase III construction has been awarded and the contractor will be mobilizing on site by early August...

Traffic Alerts

A planned shoulder closure on Westbound 37...

Nightime stoppage of traffic will be required for placement of K-rail...


Why Restore Tidal Marsh?

Estuaries provide many ecosystem services which benefit humans. We probably can't undo, but we can correct some of the damage done over the last 150 years. Here's how tidal marshes will benefit you:

Flood Protection: Improved protection against floods and sea level rise

Much of the flooding in the Bay Area occurs where runoff from major storm events collides with a rising high tide from the bay. The marshes were historic flood plains around the fringes of the bay which stored water at these collision points, absorbing it like giant sponges, then releasing during low tides.

Tidal marshes may also provide protection against sea level rise. Tidal marshes form by trapping sediment until the sediment builds up to an elevation that will support vegetation growth.  At that point, marshes gain elevation in two ways:  additional sedimentation and accumulation of organic matter below the surface of the sediment (such as roots and rhizomes of plants).  Historically, it's believed that the marshes were able to keep pace with changes in sea level by migrating inland to higher elevations. With the current predictions of sea level rise, how persistent marshes will be depends on sediment availability, the rate that sea levels rises, and presence and type of vegetation and its organic root zone building capacity.  A marsh, bound by a levee however, cannot naturally adapt to sea level rise.

Healthier Ecosystem: Reduced pollution and improved water and air quality

Perhaps the best argument for restoring diked off marshlands back to tidal marsh is for the health of the ecosystem. While most people understand that this is a good thing, most don't understand how it actually benefits them. A marsh acts as a natural filter and improves water quality by trapping and filtering nutrients, sediment and pollutants transported by runoff. This prevents these pollutants from ever reaching the bay and adversely effecting its marine life. The San Francisco Bay Estuary was once teeming with salmon, crab and oysters. The fishing industry thrived, and harvests from the Bay would not only feed the region, but much of the west coast as well. Tidal marsh was an essential component to the health of the fishing industry in the San Francisco Bay. With the closure of the herring fishery in 2009, commercial fishing and shellfishing is now prohibited. Restoring our marshes will undoubtebly improve the health of the fisheries in the Bay.

Additionally, tidal marsh can serve to purify the air. Marshes tend to be "carbon sinks" because of the amount of carbon dioxide absorbed through photosynthesis by the prolific wetland vegetation. These sinks are especially important in highly urbanized areas, like the San Francisco Bay Area, to help keep the air clean despite high carbon dioxide levels.

Recreational Opportunities: Outdoor pursuits for recreation and education

Restoring tidal marsh also provides recreational opportunities for people to experience the natural world. The San Francisco Bay Area is one of the most densely populated metropolitan areas in the United States, and we are fortunate to have such large areas close by that have not been developed. The mere geographic presence of the bay has saved the Bay Area from becoming an endless urban plain like Los Angeles. With proper planning and funding, tidal restoration projects present a unique opportunity to provide recreational areas for its residents that are, at times, right outside their front door. Activities such as hiking, biking, kayaking, fishing, birding, and hunting are only minutes away.

In a similar respect, public access to the marsh provides an educational opportunity to learn about our natural environment and how plants, animals and humans can coexist.

Sustainable Environment: A long term solution to costly maintenance requirements

Most dikes and levees in the San Francisco Bay are aging and poorly constructed relying on technology and building methods from the turn of the 19th century. Further complicating the matter is subsidence. As the land sinks deeper and deeper, the water on the tidal side places more and more pressure on the levees requiring them to be widened and strengthened to keep from failing. Every year these levees require some level of maintenance. Without constant maintenance, failures are inevitable. A levee failure can be catastrophic - such as the Jones Tract in 2004 - which cost $27.8 million to repair. Tidal restorations reduce the need for levees and are designed to restore the natural processes and let the site evolve as it needs given the specific conditions of the site. This approach provides a long term solution with minimal maintenance costs into the future.