Located in northern California the Suisun Marsh ( // soo-SOON) has been referred to as the largest brackish water marsh on west coast of the United States of America. The marsh land is part of the San Francisco Bay tidal estuary, and subject to tidal ebb and flood. The marsh is home to many species of birds and other wildlife, and is formed by the confluence of the Sacramento and San Joaquin rivers between Martinez and Suisun City, California and several other smaller, local watersheds. Adjacent to Suisun Bay, the marsh is immediately west of the legally defined Sacramento-San Joaquin Delta as well as part of the San Francisco Bay estuary.
The Suisun Marsh is named for the Suisunes, a Patwin sub-tribe, who inhabited the area around 200 years ago.
Suisun Marsh, 116,000 acres (470 km2) of land, bays, and sloughs, is one of the largest estuarine marshes in the western United States. Geologically, the Suisun Marsh is the product of water-borne sediment deposition, carried from the Sacramento and San Joaquin Rivers into the San Francisco Bay. This process—the weathering of the parent rock of the Sierra Nevada and Vaca Mountains, transport of the weathered material via rivers and creeks, and ultimate deposition into San Francisco Bay—has taken place over thousands of years and has resulted in the patchwork nature of the marsh. The marsh areas consist of peat soils formed by the decay of emergent plants over time.[ citation needed ]
Originally, Suisun Marsh was a vast stretch of tidal wetlands broken by branching tidal channels and ponds. The area alternately flooded and drained with the rise and fall of the tides. In winter, the ponds supported high numbers of migratory waterfowl. From the years of the Gold Rush to about 1880, the marsh was extensively used by market hunters to provide fresh waterfowl and feathers to San Francisco markets. From the 1880s until the 1930s, however, this area was gradually converted to agriculture, made possible by the construction of levees and dikes to hold back the water. Eventually, increasing soil salinity made cultivation and even cattle grazing unprofitable and cultivation ceased on all wetland areas. Most of the marsh was then purchased by public and private interests as habitat for waterfowl, mainly to support hunting. Later, the construction of water development projects (specifically, the federal Central Valley Project and the California State Water Project) in the Sacramento-San Joaquin watersheds altered the natural salinity regime of the marsh, making it more saline. In an effort to maintain the wetlands, the marsh landowners sought legislation to preserve the area from residential or commercial development. In addition, they pursued relief from the impacts of the water projects on the salinity regime of the marsh. As a result, the parties entered into agreements to offset the impacts of the water projects on the managed wetlands. Today, Suisun Marsh supports a diversity of fish, wildlife and plants, including a large population of river otters, a number of native fish species, and birds ranging from marsh wrens to American white pelicans. Rush Ranch has only been recently acquired and is managed for both historic and biological values. [ citation needed ]However, its habitats are being enhanced and many tidal marsh plants and animals can be seen there.
Rush Ranch is a 2070-acre (8.4 km2) remnant tidal marsh preserve within Suisun Marsh that was acquired for wildlife habitat and public access to the marsh by the Solano County Farmlands and Open Space Foundation in 1988. The non-profit organization, dedicated to protect and preserve farmland, ranchland and open space in Solano County, has since been renamed Solano Land Trust.
A component of the Solano Land Trust located at Rush Ranch is the Rush Ranch Educational Council, more commonly known as RREC. RREC is an all volunteer, non-profit organization that offers an educational program to 3rd and 4th grade students who visit the ranch on field trips. The program is offered at no charge, made possible by a grant from the Nature Conservancy in partnership with the Solano Land Trust. The program—designed to meet California K-12 education standards for history-social studies—teaches children about the original inhabitants of the ranch, the Patwin Indians, on a recreated Patwin village located on the ranch. The interactive program is divided into six stations, each focused on a facet of Patwin culture and daily life. At these stations, RREC docents use replicated tools and materials to demonstrate the ways in which the Patwins were able to thrive and ensure generational survival using seasonally available resources and by employing sustainable harvesting and natural resource conservation.[ citation needed ]
Another public part of the marsh is Grizzly Island Wildlife Area which is managed primarily for waterfowl, although over 230 species of birds have been seen here as well as many mammals, amphibians, reptiles, and fish. Grizzly Island has an unusually dense population of river otters, which can be seen swimming in its numerous sloughs, ponds, and roadside ditches. In the fall, the Grizzly Island Wildlife Area herd of tule elk breeds. The bugling of bull elk can be heard especially in the early morning and evening. Access to certain areas of the Wildlife Area is limited during the first nine days of pheasant hunting season around November, and on Wednesdays and Saturdays during the waterfowl hunting season from October through January. "Grizzly Island Wildlife Area". Local Happenings Magazine . Retrieved June 28, 2018.</ref>
Recent studies by the CALFED Suisun Marsh Levee Investigation demonstrate that the current configuration of the 230 miles of levees in the Marsh prevent salinity intrusion into the freshwater of the Delta used by 22 million people for drinking water.
As noted above, the dikes, or levees, of Suisun Marsh were originally built by nineteenth century farmers seeking to create farmland from tidal marsh. While this system is still in use on the Sacramento-San Joaquin Delta islands to the east, it failed in the Suisun Marsh due to unacceptably high soil salinities. Portions of the marsh were subsequently converted from farming to permanently and seasonally flooded wetlands in the twentieth century. Today, approximately 230 miles of levees maintain seasonally and permanently flooded wetlands. Between approximately mid-October and mid-January, managed seasonal wetlands are flooded to a depth of 8 to 12 inches to attract waterfowl.
The rest of the year, the ponds are flooded and drained on a schedule designed to optimize conditions for plants which provide seeds preferred by waterfowl, namely alkali bulrush, fat hen, and brass buttons. Ponds left flooded through at least the spring provide brood rearing habitat. The flood-and-drain cycle is also designed to minimize soil salinity by leaching and flushing salts. Today, this flood management program also supports plants such as tules, cattails, saltgrass, and pickleweed, which may not yield preferred waterfowl food seeds, but do provide habitat for invertebrates important to pre-breeding waterfowl and other wildlife.
When Suisun agricultural lands reverted to wetlands, they provided habitat for waterfowl displaced decades earlier by reclamation. In addition, the presence of these "new" wetlands eased waterfowl crop depredation in the Central Valley. It also provided habitat no longer available in the Central Valley due to extensive reclamation for agriculture and urbanization. By about 1930, waterfowl hunting had become the primary use of the Suisun Marsh. It is the dominant use today, with 158 private duck clubs and large public hunting areas.
The wetland managers for both the private hunting clubs and the state's public land take water from major and minor sloughs throughout the marsh. Montezuma Slough, one of the largest, is open at both ends, and its flood tide current is longer and stronger than its ebb tide current, causing a net west-to-east flow which draws higher saline water eastward from Grizzly Bay.
The flood tide pushing through the slough takes half an hour longer to traverse the marsh than does the matching flood tide following the more direct route in the main Suisin Bay channel.Thus, high tide at the east end of the slough arrives out of phase with high tide in the main channel, and rather than being pushed back, as it would be in the main channel or in a dead-end slough, the slough water keeps flowing eastward, drawing more saline water with it.
To meet the salinity requirements stipulated by the California Water Resources Control Board to support "beneficial uses" in Decision-1485, the California State Water Project and the federal Central Valley Project built the Montezuma Slough Salinity Control Gates. They began operation in 1989. The gates span Montezuma Slough near the Roaring River intake and are periodically operated from October to May to meet the more recently established salinity standards set by Decision-1641, to block the salty flood tide from Grizzly Bay but allow passage of the freshwater ebb tide from the mouth of the Sacramento-San Joaquin Delta.
Because the Salinity Control Gates are more effective than anticipated other proposed salinity control measures were abandoned. The gates operate as needed from October through May.
Although the Suisun Marsh is managed for waterfowl, it is also an important fish habitat, especially for wild salmon. Monitoring stations throughout the marsh measure the impact of water management activities on fish populations, and fish screens prevent the diversion and entrapment of fish in the waterfowl ponds.
The Marsh supports 80% of the state's commercial salmon fishery by providing important tidal rearing areas for juvenile fish allowing them to grow twice as fast as those reared in the upper watershed, thus, greatly enhancing their survival. And is an important area for native fishes including the delta smelt which is protected by the federal Endangered Species Act.
Suisun Marsh is home to the only two known occurrences of the Suisun thistle, Cirsium hydrophilum var. hydrophilum, a variety of thistle which is a federally listed endangered species.The Suisun thistle is perennial and stays in its juvenile stages of life until it is ready to flower and once the rosette reaches its mature phase it can take up to a year or more to develop the leafy stem.
Tulare Lake is a freshwater dry lake with residual wetlands and marshes in the southern San Joaquin Valley, California, United States. After Lake Cahuilla disappeared in the 17th century, Tulare Lake was the largest freshwater lake west of the Mississippi River and the second-largest freshwater lake entirely in the United States, based upon surface area. A remnant of Pleistocene-era Lake Corcoran, Tulare Lake dried up after its tributary rivers were diverted for agricultural irrigation and municipal water uses.
Suisun Bay is a shallow tidal estuary in northern California. It lies at the confluence of the Sacramento River and San Joaquin River, forming the entrance to the Sacramento–San Joaquin River Delta, an inverted river delta. Suisun Marsh, the tidal marsh land to the north, is the largest marsh in California. Grizzly Bay forms a northern extension of Suisun Bay. Suisun Bay is directly north of Contra Costa County.
The Guadalupe River mainstem is an urban, northward flowing 14 miles (23 km) river in California whose much longer headwater creeks originate in the Santa Cruz Mountains. The river mainstem now begins on the Santa Clara Valley floor when Los Alamitos Creek exits Lake Almaden and joins Guadalupe Creek just downstream of Coleman Road in San Jose, California. From here it flows north through San Jose, where it receives Los Gatos Creek, a major tributary. The Guadalupe River serves as the eastern boundary of the City of Santa Clara and the western boundary of Alviso, and after coursing through San José, it empties into south San Francisco Bay at the Alviso Slough.
The Sacramento–San Joaquin River Delta, or California Delta, is an expansive inland river delta and estuary in Northern California. The Delta is formed at the western edge of the Central Valley by the confluence of the Sacramento and San Joaquin rivers and lies just east of where the rivers enter Suisun Bay. The Delta is recognized for protection by the California Bays and Estuaries Policy. Sacramento–San Joaquin Delta was designated a National Heritage Area on March 12, 2019. The city of Stockton is located on the San Joaquin River on the eastern edge of the delta. The total area of the Delta, including both land and water, is about 1,100 square miles (2,800 km2). Its population is around 500,000 residents.
The Yolo Bypass is one of the two flood bypasses in California's Sacramento Valley located in Yolo and Solano Counties. Through a system of weirs, the bypass diverts floodwaters from the Sacramento River away from the state's capital city of Sacramento and other nearby riverside communities.
The Goleta Slough is an area of estuary, tidal creeks, tidal marsh, and wetlands near Goleta, California, United States. It primarily consists of the filled and unfilled remnants of the historic inner Goleta Bay about 8 miles (13 km) west of Santa Barbara. The slough empties into the Pacific Ocean through an intermittently closed mouth at Goleta Beach County Park just east of the UCSB campus and Isla Vista. The slough drains the Goleta Valley and watershed, and receives the water of all of the major creeks in the Goleta area including the southern face of the Santa Ynez Mountains.
The delta smelt is an endangered slender-bodied smelt, about 5 to 7 cm long, in the family Osmeridae. Endemic to the upper Sacramento-San Joaquin Estuary of California, it mainly inhabits the freshwater-saltwater mixing zone of the estuary, except during its spawning season, when it migrates upstream to fresh water following winter "first flush" flow events. It functions as an indicator species for the overall health of the Delta's ecosystem.
Sorex ornatus sinuosus, the Suisun shrew or Suisun ornate shrew, is a subspecies of the ornate shrew that occurs in the tidal marshes of the northern shores of San Pablo and Suisun bays. Brown and Rudd redefined the western boundary of the range from a prior designation of the Petaluma River. The Suisun shrew has been designated as a Species of Concern by the U.S. government and a Mammalian Species of Special Concern by the state of California.
Seal Slough is a narrow winding tidal channel through a tidal marsh in San Mateo and Foster City, California. This slough has been the object of a wetland restoration project in recent years to enhance habitat value. Dredging has been carried out in Seal Slough since at least 1954. When the original sewage treatment plant for the city of San Mateo was constructed in 1935, its discharge was directed to Seal Slough.
Cordelia Slough is a 10.8-mile-long (17.4 km) tidal watercourse which discharges to the Suisun Slough, which in turn empties into Grizzly Bay in Solano County, California. The Suisun Slough, fed by the Green River and Red Top Creek, provides a productive habitat for a diversity of aquatic flora and fauna. In particular steelhead migrate up Cordelia Slough to spawn in its two tributaries.
The Yolo Bypass Wildlife Area is located within the Yolo Bypass in Yolo County, California. The wildlife area is managed by the California Department of Fish and Wildlife with the intent of restoring and managing a variety of wildlife habitats in the Yolo Basin, a natural basin in the north part of the Sacramento-San Joaquin River Delta. The creation of the wildlife area was spearheaded by the Yolo Basin Foundation. The California Department of Fish and Wildlife and Yolo Basin Foundation are the core partners in the operation of this unique community resource. Located at
The San Francisco Estuary together with the Sacramento–San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.
Sherman Island is an island in the Sacramento-San Joaquin River Delta at the confluence of the two rivers in Sacramento County, California, 1.2 miles (1.9 km) northeast of Antioch. The 5,500 ha island, mostly managed by Reclamation District 341, is the meeting point of Sacramento, Solano, and Contra Costa Counties, and is bordered on the north and northwest by the Sacramento River, on the northeast by Three Mile Slough, and on the east, and south west by the San Joaquin River. Sherman Island is a widely known kite and windsurfing area.
Cirsium hydrophilum is a species of thistle which is endemic to California, where it is found only in the San Francisco Bay Area and the Sacramento-San Joaquin River Delta. This native thistle grows in wet boggy habitats.
Big Break Regional Shoreline is a regional park in Oakley, Contra Costa County, northern California. It is a part of the East Bay Regional Park District system.
Winter Island is a 453-acre (183 ha) island in Suisun Bay, in the western Sacramento-San Joaquin River Delta. It is north of Pittsburg, separated from Browns Island to the west by a slough. It was private property, and contained one house. It is used as a duck hunting area, a wetland, and a dredging disposal area. In 2016 Winter Island was purchased by the California Department of Water Resources in order to restore the island as a tidal marsh. Winter Island is part of Contra Costa County, and managed by Reclamation District 2122. It is shown, labeled "Ruckels Island", on an 1850 survey map of the San Francisco Bay area made by Cadwalader Ringgold and an 1854 map of the area by Henry Lange.
Seawater intrusion is either caused by groundwater extraction or increased in sea level. For every 1 foot of freshwater depression, sea-salty waters rises 40 feet as the cone of depression forms. Salinization of groundwater is one of the main water pollution ever produced by mankind or from natural processes. It degrades water quality to the point it passes acceptable drink water and irrigation standards. To this day, the State of California enforced several methodologies through technical innovation and scientific approach to combat saltwater intrusion in areas vulnerable to saltwater intrusion.
The San Francisco Bay Salt Ponds are an approximately 16,500-acre (6,700 ha) part of the San Francisco Bay that have been used as salt evaporation ponds since the California Gold Rush era. Most of the ponds were once wetlands in the cities of Redwood City, Newark, Hayward and other parts of the bay.
Joice Island is a small island in Grizzly Bay in the San Francisco Bay Area of California. It is part of Solano County, and partially administered by Reclamation District 2141. It is bordered on the east by Montezuma Slough, on the south by Morrow Island, on the west by Suisun Slough, and on the north by Cutoff Slough. Its coordinates are. An unlabeled island, in the same approximate location as the southernmost part of Joice Island, is shown on an 1850 survey map of the San Francisco Bay area made by Cadwalader Ringgold and an 1854 map of the area by Henry Lange.
Van Sickle Island is an approximately 10,000-acre (4,000 ha) island in Suisun Bay, California. It is part of Solano County, and administered by Reclamation District 1607. Its coordinates are, and in 1981 the United States Geological Survey recorded its elevation as 0 ft (0 m).