|Native name||Spanish: Estero de Sonoma|
|Region||Sonoma and Napa counties|
|Cities||Kenwood, Glen Ellen, El Verano, Sonoma|
|• location||4 mi (6 km) southwest of St. Helena, California|
|• elevation||2,480 ft (760 m)|
|Mouth||San Pablo Bay|
|11 mi (18 km) west of Vallejo, California|
|0 ft (0 m)|
|Basin size||170 sq mi (440 km2)|
|• left||Calabazas Creek, Schell Creek|
|• right||Yulupa Creek, Asbury Creek, Dowdall Creek, Fowler Creek, Graham Creek, Bear Creek|
Sonoma Creek is a 33.4-mile-long (53.8 km) stream in northern California. It is one of two principal drainages of southern Sonoma County, California, with headwaters rising in the rugged hills of Sugarloaf Ridge State Park and discharging to San Pablo Bay, the northern arm of San Francisco Bay. The watershed drained by Sonoma Creek is roughly equivalent to the wine region of Sonoma Valley, an area of about 170 square miles (440 km2). The State of California has designated the Sonoma Creek watershed as a “Critical Coastal Water Resource”. To the east of this generally rectangular watershed is the Napa River watershed, and to the west are the Petaluma River and Tolay Creek watersheds.
This south flowing river drains the western slopes of the Mayacamas Range, the southern slopes of Annadel State Park and the eastern slopes of the Sonoma Mountains with intermittent winter flows in the higher tributary reaches. As the tributaries and headwaters reach the valley floor, a perennial stream cuts through scenic and valuable vineyards of Kenwood. Sonoma Creek veers west at Kenwood and cuts a gorge running parallel to Warm Springs Road, where it turns south to historic Glen Ellen, passing within one mile (1.6 kilometers) of Jack London State Historic Park and the Wolf House and thence southward paralleling Arnold Drive. In the city of Sonoma it is an urban creek which emerges into agricultural areas to the south. Finally, Sonoma Creek discharges to the vast Napa-Sonoma Marsh at the northern tip of San Pablo Bay. Principal tributaries to the creek include Yulupa Creek, Graham Creek, Calabazas Creek, Bear Creek, Schell Creek, and Fowler Creek.
Headwaters rise on the west facing slopes of the inner coast southern Mayacamas Mountains, where the highest peaks are Hood Mountain, elevation 2750 feet (833 m) and Bald Mountain, elevation 2729 feet (826 m), each of which has views of the Pacific Ocean and the Sierra Nevada range. The headwaters cut through gorge and meadow of Sugarloaf Ridge State Park, which boasts 25 miles (40 kilometers) of self-guided trails and the Robert Ferguson Observatory. There is also a 25 foot (eight meter) high waterfall, present only when fed by the winter rains but can persist until late May for high rainfall years such as 2006. In the 100 foot (30 m) deep gorge into which the waterfall spills is a moist mixed forest habitat including California bay laurel, coast redwood, Douglas fir, big leaf maple, cherry holly, coffeeberry, and even tanbark oak. The understory features abundant ferns and boulder laden mosses. A prominent landform in this upper reach created by Sonoma Creek is Adobe Canyon. Locally part of this upper reach flow is sometimes called Adobe Creek. Tributaries near the headwaters include Mount Hood Creek and Graywood Creek.
A diversity of aquatic and terrestrial organisms populate Sonoma Creek and its riparian zone. Winter-run Chinook salmon (Oncorhynchus tsawytscha), Delta smelt (Hypomesus transpacificus) and steelhead (Oncorhynchus mykiss) are the most prominent fishes. Anadromous fish movements in Sonoma Creek have been studied extensively not only in the mainstem Sonoma Creek, but in some of the tributaries. These investigations have demonstrated a historical decline in spawning and habitat value for these species, primarily due to sedimentationand secondarily to removal of riparian vegetation since the 1800s.
A variety of salamanders, snakes and frogs are also present. The federally listed as threatened California red-legged frog is present in the northern reach draining the south slopes of Annadel State Park. Several endangered species (mostly associated with the marshy discharge area) present include California clapper rail (Rallus longirostris), California black rail (Laterallus jamaicensis), California brown pelican (Pelicanus occidentalis), California freshwater shrimp ( Syncaris pacifica ), salt marsh harvest mouse (Reithrodontomys raviventris ), Suisun shrew (Sorex ornatus sinuosus), Sacramento splittail (Pogonichtys macrolepidotus). The above are endangered species with the exception of the splittail, steelhead and black rail, which species are federally designated as threatened.
California golden beaver ("Castor canadensis subauratus") were historically abundant along Sonoma Creek but were trapped out in the California Fur Rush of the late eighteenth and early nineteenth centuries. In 1828 fur trapper Michel La Framboise travelled from the Bonaventura River to San Francisco and then the missions of San José, San Francisco Solano and San Rafael Arcángel. La Framboise stated that "the Bay of San Francisco abounds in beaver", and that he "made his best hunt in the vicinity of the missions".The beaver were likely wiped out by the mid-nineteenth century but returned to Sonoma Creek, likely from the Delta, in the 1990s. In 1996 a beaver family developed a taste for merlot grapevine bark in a vineyard beside the creek and were exterminated, leading to civic uproar and a shift to accommodate beaver resettlement. Sonoma Ecology Center executive director Richard Dale reports that although beavers fell trees and dam culverts, on balance they perform nearly "perfect stream restoration," because they cause the creation of deep pools, slowing the flow of flood water and enhancing fishery habitat. New beavers have recolonized Sonoma Creek and are currently located in both Sonoma and Glen Ellen. A "keystone species", the beaver have created habitat that has, in turn, led to the return of river otter ("Lontra canadensis") which have been sighted recently in the beaver pond below the Boyes Boulevard bridge in Boyes Hot Springs.
Upland ecosystems drained include mixed California oak woodland, chaparral and savannah woodland, In these upland reaches one finds plentiful black-tailed deer, coyote, skunk, raccoon, opossum, wild turkey, turkey vulture, red-tailed hawk and occasionally bobcat and mountain lion. Prominent higher elevation trees include: coast live oak, Garry oak, Pacific madrone, California buckeye, Douglas fir, whereas valley oak is prevalent on the Sonoma Valley floor.
Up until about 1850, Sonoma Creek was unchanged from its natural state. Adverse erosion and bank cutting were at sustainable levels and did not add enough turbidity to the creek system to discourage aquatic species. Flooding in the downstream reaches did not realize the modern frequencies since all the creek reaches could absorb more excess water from peak rainfall events. The Kenwood area existed in the form of a large marsh effectively blocked by a natural earthen dam from penetrating the course of the creek as it flows west out of Kenwood toward Glen Ellen.
With the advent of more intensive farming of Sonoma Valley in the latter half of the 19th century, the Kenwood Marsh was drained in favor of grazing, vineyards and other agricultural uses. This action removed the largest upstream buffer that assisted flood control in the lower reaches of Sonoma Creek. Consequently, the frequency and severity of modern floods (1960s onward) has been exacerbated by these interventions of humans.
In 1978, Sonoma Creek was named a historic resource by the Sonoma League of Historic Preservation for being "one of the most picturesque sites and valuable natural resources in Sonoma County."
The State of California Regional Water Quality Control Board considers the most significant water quality parameters in Sonoma Creek to be: turbidity, pathogens and nitrates. Turbidity is an issue because of historical problems of erosion of stream banks, especially in the presence of ongoing land development in Sonoma Valley. Increased sedimentation has a variety of adverse impacts including direct harm to aquatic organisms and the more specific impact of altering streambed gravels to reduce productivity of spawning habitats; additionally sedimentation of pools decreases the efficacy of anadromous fish summering habitat by increasing critical summer water temperatures in these pools.Pathogens appear to be linked to septic tank or leach field failures in some of the rural reaches, particularly in the upper valley sections. Nitrates enter the stream system from excess fertilizers applied to land uses in the drainage basin and may also be present in septic wastes improperly entering the creek. Sediment and nitrates may also enter the stream through urban stormwater runoff in the city of Sonoma reach.
Because Sonoma Creek is the sole drainage flow of the Sonoma Valley Wine Country, it is a vital resource for aquifer recharge. Proportionally a greater percent of Sonoma Creek feeds recharge than its neighbors, the Napa and Petaluma Rivers. This outcome derives from the presence of pervious valley floor alluvial soils and the gentle stream gradients along the valley floor, where most of the reaches occur. The valley itself is part of the Franciscan Complex, which includes crumpled, uplifted terranes that have resulted from the subduction of the former oceanic Farallon Plate under the North American continent. The area is attended by volcanism and sediments, deposited in the lagoons behind its island arcs, which resulted from geological events dating from 140 to 42 million years. Recharge for the Sonoma Valley is critical because local rainfall is only about 29 inches (74 centimeters) per year. Grape growing and wine production require considerable groundwater extraction, and there is controversy over wineries use of annual creeks and waterways.
This large marsh area has been reduced considerably from its historic dimensions due to construction of multiple levee systems and encroachment by agriculture and other forms of development. This Napa-Sonoma Marsh has been formed largely by sedimentary deposits over the last two million years. The basement depositional layer is the Alameda group. Higher are Old bay mud and Young bay mud, between which there are intermediate deposits of the Alameda formation, which consists of alluvial and swamp origins. The entire marsh area is considered subject to liquefaction in the case of a major seismic event. feet (1.7 m).The marsh is subject to diurnal tidal variations of approximately 5.5
Historically the marsh supported an extremely diverse wetlands ecosystem, with a variety of primary productivity plants including pickleweed, eelgrass and giant bulrush ( Scirpus californiens ). There has also been historically significant fish, mammal, amphibian and avafauna. The marsh is a significant element within the Pacific Flyway providing resting and feeding areas for migratory birds. As of 2006 this ecosystem has been significantly compromised by fill, levee formation, dredging and other development; estimates generally state that 75 percent of the original biological productivity of the marsh has been destroyed. However, it remains a significant habitat and is subject to meaningful wetland restoration activity, that is being actively evaluated as of the 2000–2006 timeframe.
Because of the recognition of impacts of land development and land use practices, which began in the mid-19th century and have continued until 2006, certain actions are being consideredby the Board of Supervisors of Sonoma County. Most notably a special parcel tax may be submitted to voters to assess landowners adjacent to Sonoma Creek. These funds could be used in flood control, hydrology modeling studies, stream conservation work, including erosion control and wildlife conservation. Other current activities include considerable research in public and private sectors including work by the U.S. Army Corps of Engineers, Sonoma County and various private conservation groups.
Due to overpopulation of Sonoma Valley as well as overly intensive agriculture, groundwater supplies have been drawn down to the point of causing deleterious effects.The U.S. Geological Survey has found in the Carneros region between Sonoma Creek and the Napa Ridge that due to excessive groundwater drawdown, saltwater intrusion is already occurring, rendering water unsuitable for many uses.
Wine Country is the region of California, in the northern Bay Area, known worldwide as a premier wine-growing region. The region is famed for its wineries, its cuisine, Michelin star restaurants, boutique hotels, luxury resorts, historic architecture, and culture. Viticulture and wine-making have been practiced in the region since the Spanish missionaries from Mission San Francisco Solano established the first vineyards in 1812.
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 Napa River is a river approximately 55 miles (89 km) long in the U.S. state of California. It drains a famous wine-growing region called the Napa Valley, in the mountains north of the San Francisco Bay. Milliken Creek and Mt. Veeder watersheds are a few of its many tributaries. The river mouth is at Vallejo, where the intertidal zone of fresh and salt waters flow into the Carquinez Strait and the San Pablo Bay.
Sonoma Valley is a valley located in southeastern Sonoma County, California, in the North Bay region of the San Francisco Bay Area. Known as the birthplace of the California wine industry, the valley is home to some of the earliest vineyards and wineries in the state, some of which survived the phylloxera epidemic of the 1870s and the impact of prohibition in the early 20th century. Today, the valley's wines are protected by the U.S. Federal Government's Sonoma Valley and Carneros AVAs.
Coyote Creek is a river that flows through the Santa Clara Valley in Northern California. Its source is on Mount Sizer, in the mountains east of Morgan Hill. It eventually flows into Anderson Lake in Morgan Hill and then northwards through Coyote Valley to San Jose, where it empties into San Francisco Bay.
The Sweetwater River is a 55-mile (89 km) long stream in San Diego County, California.
Lagunitas Creek is a 24 miles (39 km)-long northward-flowing stream in Marin County, California. It is critically important to the largest spawning runs of endangered coho salmon in the Central California Coast Coho salmon Evolutionary Significant Unit. The stream's headwaters begin on the northern slopes of Mount Tamalpais in the Coast Range and terminate in southeast Tomales Bay, 1.5 miles (2.4 km) northwest of Point Reyes Station, California. Lagunitas Creek feeds several reservoirs on Mt. Tamalpais that supply a major portion of the county's drinking water.
Alameda Creek is a large perennial stream in the San Francisco Bay Area. The creek runs for 45 miles (72 km) from a lake northeast of Packard Ridge to the eastern shore of San Francisco Bay by way of Niles Canyon and a flood control channel.
The Russian River is a southward-flowing river that drains 1,485 sq mi (3,850 km2) of Sonoma and Mendocino counties in Northern California. With an annual average discharge of approximately 1,600,000 acre feet (2.0 km3), it is the second-largest river flowing through the nine-county Greater San Francisco Bay Area, with a mainstem 110 mi (180 km) long.
Mount Hood, also known as Hood Mountain is a mountain near the southeastern edge of Santa Rosa, California at the northeast of the Sonoma Valley and attains a height of 2,733 feet (833 m). The original name was Mount Wilikos, an Indian name meaning "willows." Most of the drainage from Mount Hood contributes to the headwaters of Sonoma Creek. A prominent feature is the extensive rock face visible on the upper half of the mountain as viewed from State Route 12. The habitats on the mountain include mixed oak forest, pygmy forest, chaparral and riparian zones. In prehistoric times the slopes of Mount Hood were inhabited by a division of the Yuki tribe. Most of Mount Hood is within the Hood Mountain Regional Park maintained by Sonoma County. Mount Hood is part of the inner coast Mayacamas Range, and lies mostly within Sonoma County, with a part of the mountain geographically within Napa County. Mount Hood affords overlooks of the Pacific Ocean, San Francisco Bay and "a spectacular view east to the Sierra Nevada Range."
Santa Rosa Creek is a 22-mile-long (35 km) stream in Sonoma County, California, which rises on Hood Mountain and discharges to the Laguna de Santa Rosa by way of the Santa Rosa Flood Control Channel. This article covers both the creek and the channel.
Yulupa Creek is a 2.8-mile-long (4.5 km) southeast-flowing perennial stream that rises on the southeastern flanks of the northern Sonoma Mountains in Sonoma County, California, United States. This creek, which drains the eastern slopes of Bennett Mountain, is tributary to Sonoma Creek, which in turn discharges to San Pablo Bay.
Arroyo Seco is a 6.9-mile-long (11.1 km) tributary stream to Schell Creek in southern Sonoma County, California, United States. In Spanish arroyo seco means "dry creek".
Arroyo Corte Madera del Presidio is a 4.1-mile-long (6.6 km) year-round stream in southern Marin County, California, United States. This watercourse is also known as Corte Madera Creek, although the actual stream of that name flows into San Francisco Bay further north at Point San Quentin. This watercourse has a catchment basin of about 8 square miles (21 km2) and drains the south-eastern slopes of Mount Tamalpais and much of the area in and around the town of Mill Valley; this stream discharges to Richardson Bay.
The Napa Sonoma Marsh is a wetland at the northern edge of San Pablo Bay, which is a northern arm of the San Francisco Bay in California, United States. This marsh has an area of 48,000 acres (194 km2), of which 13,000 acres (53 km2) are abandoned salt evaporation ponds. The United States Government has designated 13,000 acres (53 km2) in the Napa Sonoma Marsh as the San Pablo Bay National Wildlife Refuge.
Sugarloaf Ridge State Park is a state park in Northern California, United States. Located in the Mayacamas Mountains north of Kenwood, the park straddles the boundary between Sonoma and Napa counties. The park contains the 2,729-foot (832 m) Bald Mountain and the headwaters of Sonoma Creek including a 25-foot (8 m) tall seasonal waterfall. The park is also home to the volunteer-run Robert Ferguson Observatory. Camping, picnicking, horseback riding, mountain biking, stargazing, fishing and hiking are common attractions of Sugarloaf. The park boasts 25 miles of trails with trails ranging from less than a mile to 8.8 miles, and elevation gains reaching 2,500 feet.
Pescadero Creek is a major stream in Santa Cruz and San Mateo counties in California, United States. At 26.6 miles (42.8 km), it is the longest stream in San Mateo County and flows all year from springs in the Santa Cruz Mountains. Its source is at 1,880 feet (570 m) above sea level on the western edge of Castle Rock State Park, with additional headwaters in Portola Redwoods State Park, and its course traverses Pescadero Creek County Park and San Mateo County Memorial Park before entering Pescadero Marsh Natural Preserve at Pescadero State Beach and thence to the Pacific Ocean 14.4 miles (23 km) south of Half Moon Bay.
Alhambra Creek is a stream in Contra Costa County, in the East Bay region of the San Francisco Bay Area in northern California.
San Mateo Creek is a stream in Southern California in the United States, whose watershed mostly straddles the border of Orange and San Diego Counties. It is about 22 miles (35 km) long, flowing in a generally southwesterly direction. Draining a broad valley bounded by the Santa Ana Mountains and Santa Margarita Mountains, San Mateo Creek is notable for being one of the last unchannelized streams in Southern California.
The 40-acre Los Guillicos Preserve lies in the Valley of the Moon at the foot of Hood Mountain in the Mayacamas Mountain Range. Oak woodlands of the Preserve are within the Sonoma Creek Watershed. This land was included in the 1837 Rancho Los Guilicos Mexican Land Grant. Since 2011, the Preserve has been managed by Sonoma State University's Center for Environmental Inquiry.
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