- Sonoma Creek
Geobox|River
name = Sonoma Creek
native_name =
other_name =
category =stream
etymology =
nickname =
image_caption =Waterfall at Sugarloaf Mountainheadwaters of Sonoma Creek
country =United States
state =California
region = Sonoma and Napa counties
district =
municipality =
parent =
tributary_right =Yulupa Creek
tributary_right1 =Asbury Creek
tributary_right2 =Dowdall Creek
tributary_right3 =Fowler Creek
tributary_right4 =Graham Creek
tributary_right5 = Bear Creek
tributary_left =Calabazas Creek
tributary_left1 =Schell Creek
city = Kenwood
city1 = Glen Ellen
city2 = El Verano
city3 = Sonoma
landmark =
river =
source = Bald Mountain
source_location = convert|4|mi|km|0|lk=on|abbr=on southwest ofSt. Helena, California
source_region = | source_country =
source_elevation_imperial = 2480
source_elevation_note =
source_lat_d = 38 | source_lat_m = 27 | source_lat_s = 23 | source_lat_NS = N
source_long_d = 122 | source_long_m = 30 | source_long_s = 25 | source_long_EW = W
source_coordinates_note = Gnis|234882|Sonoma Creek]
source1 =
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mouth =San Pablo Bay
mouth_location = convert|11|mi|km|0|abbr=on west ofVallejo, California
mouth_region = | mouth_country =
mouth_elevation_imperial = 0
mouth_lat_d = 38 | mouth_lat_m = 9 | mouth_lat_s = 2 | mouth_lat_NS = N
mouth_long_d = 122 | mouth_long_m = 24 | mouth_long_s = 13 | mouth_long_EW = W
mouth_coordinates_note =
length_imperial =
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depth_imperial =
volume_imperial =
watershed_imperial = 170
discharge_location =
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free = | free_type =
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footnotes =Sonoma Creek is a
stream inNorthern California . It is one of two principal drainages of SouthernSonoma County, California , with headwaters rising in the rugged hills ofSugarloaf Ridge State Park and discharge toSan Pablo Bay , the northern arm ofSan Francisco Bay . The watershed drained by Sonoma Creek is roughly equivalent to the wine region ofSonoma Valley , an area of about 170 square miles (435 square kilometers). The State ofCalifornia has designated the Sonoma Creek watershed as a “Critical Coastal Water Resource”. ["Critical Coastal Waters Draft Strategic Plan", State of California (2002)] To the east of this generally rectangular watershed is theNapa River watershed, and to the west are thePetaluma River andTolay Creek watersheds.This south flowing
river drains the western slopes of the Mayacamas Range, the southern slopes ofAnnadel State Park and the eastern slopes of theSonoma 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 valuablevineyard s of Kenwood. Sonoma Creek veers west at Kenwood and cuts agorge running parallel to Warm Springs Road, where it turns south to historicGlen Ellen , passing within one mile (1.6 kilometers) ofJack London State Historic Park and the Wolf House and thence southward paralleling Arnold Drive. In the city ofSonoma, California it is an urban creek which emerges into agricultural areas to the south. Finally Sonoma Creek discharges to the vastNapa-Sonoma Marsh at the northern tip ofSan Pablo Bay . Principal tributaries to the creek includeYulupa Creek ,Graham Creek ,Calabazas Creek , Bear Creek,Schell Creek , andFowler Creek .Ecology
A diversity of aquatic and terrestrial
organism s populate Sonoma Creek and itsriparian zone . Winter-runChinook salmon ("Oncorhynchus tsawytscha"),Delta smelt ("Hypomesus transpacificus") andsteelhead ("Onchorhynchus mykiss") are the most prominentfish es.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 tosedimentation "Sonoma Creek Watershed Limiting Factors Analysis", Sonoma Ecology Center, with support from theU.S. Army Corps of Engineers , December, 2004] and secondarily to removal of riparian vegetation since the 1800s.A variety of
salamander s,snake s andfrogs are also present. The federally listed as threatenedCalifornia red-legged frog is present in the northern reach draining the south slopes ofAnnadel State Park . Severalendangered species (mostly associated with the marshy discharge area) present includeCalifornia clapper rail ("Rallus longirostris"), CaliforniaBlack Rail ("Laterallus jamaicensis"), Californiabrown pelican ("Pelicanus occudentalis"), California freshwater shrimp ("Syncaris pacifica "),Salt marsh harvest mouse ("Reithrodontomys raviventris" ),Suisun Shrew ("Sorex ornatus sinuosus)",Sacramento splittail ("Pogonichtys macrolepidotus"). The above areendangered species with the exception of the splittail, steelhead and black rail, which species are federally designated as Threatened.Upland ecosystems drained include mixed
California oak woodland ,chaparral andsavannah woodland , In these upland reaches one finds plentifulBlack-tailed Deer ,coyote , skunk, raccoon, opossum,wild turkey ,turkey vulture ,red-tailed hawk and occasionally bobcat andmountain lion . Prominent higher elevation trees include:Coast live oak ,Garry Oak ,Pacific madrone ,California Buckeye ,Douglas fir , whereasValley oak is prevalent on theSonoma Valley floor.Water quality
The State of California Regional Water Quality Control Board considers the most significant
water quality parameters in Sonoma Creek to be:turbidity ,pathogen s andnitrate s. Turbidity is an issue because of historical problems of erosion of stream banks, especially in the presence of ongoing land development inSonoma Valley . Increasedsedimentation has a variety of adverse impacts including direct harm to aquatic organisms and the more specific impact of alteringstreambed gravel s 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."Sonoma Creek Watershed Limiting Factors Analysis", Sonoma Ecology Center, with support from theU.S. Army Corps of Engineers , December, 2004] Pathogens appear to be linked toseptic tank orleach 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 urbanstormwater runoff in the city of Sonoma reach. ["Environmental Impact Report for the Fourth Street Retail Center, Sonoma, California", Earth Metrics, California State Clearinghouse (1985)]Headwaters
Headwaters rise on the west facing slopes of the inner coast southern
Mayacamas Mountains , where the highest peaks areHood Mountain , elevation 2750 feet (833 meters) and Bald Mountain, elevation 2729 feet (826 meters), each of which has views of the Pacific Ocean and the Sierra Nevada range. The headwaters cut throughgorge and meadow ofSugarloaf Ridge State Park , which boasts 25 miles (40 kilometers) of self-guidedtrail s and theRobert 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 meter) deep gorge into which the waterfall spills is a moist mixed forest habitat including Californiabay laurel ,Coast redwood ,Douglas fir , Big leaf maple, Cherry holly,Coffeeberry , and evenTanbark Oak . The understory features abundantfern s and boulder ladenmoss es. A prominentlandform in this upper reach created by Sonoma Creek isAdobe Canyon . Locally part of this upper reach flow is sometimes called Adobe Creek. Tributaries near the headwaters include Mount Hood Creek and Graywood Creek. ["Environmental Impact ReportSonoma Country Inn", County of Sonoma Permit and Resource Management Agency, November, 2004]History of the creek
Up until about 1850 Sonoma Creek operated in a virtual
prehistoric fashion. Adverseerosion and bank cutting were at sustainable levels and did not add enoughturbidity 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 earthendam from penetrating the course of the creek as it flows west out of Kenwood towardGlen Ellen .With the advent of more intensive
farming of Sonoma Valley in the latter half of the nineteenth century, the KenwoodMarsh was drained in favor ofgrazing ,vineyard s 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 (1980s onward) has been exacerbated by these interventions of humans.Wine production
Because Sonoma Creek is the sole drainage flow of the
Sonoma Valley Wine Country , it is a vital resource foraquifer recharge. Proportionally a greater percent of Sonoma Creek feeds recharge than its neighbors, the Napa andPetaluma River s. This outcome derives from the presence of pervious valley flooralluvial soils and the gentle stream gradients along the valley floor, where most of the reaches occur. The valley itself is part of theFranciscan Complex , which includes crumpled, upliftedterrane s that have resulted from thesubduction of the former oceanicFarallon Plate under the North American continent. The area is attended byvolcanism and sediments, deposited in the lagoons behind itsisland arc s), 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 annum. Grape growing andwine production require considerablegroundwater extraction. Some of the principal upper reach wineries in Kenwood are Saint Francis Winery, Kunde Winery, Kenwood Winery, Chateau Saint Jean, Mayo Winery,Remick Ridge Vineyards and VJB Winery. Wineries in the middle reach include: B.J. Cohn, Valley of the Moon Winery, Imagery and Sebastiani. In the lower reach one finds Gloria Ferrer, Carneros and Ravenswood wineries.Discharge to San Pablo Bay
This large marsh area has been reduced considerably from its historic dimensions due to construction of multiple
levee systems and encroachment byagriculture and other forms of development. ThisNapa-Sonoma Marsh has been formed largely bysedimentary deposits over the last two million years. The basement depositional layer is theAlameda group . Higher are Oldbay mud and Young bay mud, between which there are intermediate deposits of theAlameda formation , which consists ofalluvial andswamp origins. The entire marsh area is considered subject toliquefaction in the case of a majorseismic event. [ [http://www.napa-sonoma-marsh.org/objectives.html Napa-Sonoma Marsh Restoration Project, California Department of Fish and Game] ] Themarsh is subject to diurnaltidal variations of approximately 5.5 feet (1.7 meters).Historically the marsh supported an extremely diverse
wetlands ecosystem , with a variety of primary productivity plants includingpickleweed ,eelgrass and giant bulrush ("Scirpus californiens "). There has also been historically significant fish,mammal ,amphibian and avafauna. The marsh is a significant element within thePacific 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 meaningfulwetland restoration activity, that is being actively evaluated as of the 2000-2006 timeframe. [ [http://www.spn.usace.army.mil/projects/sonomacreekpmp.pdf Sonoma Creek and Tributaries Feasibility Report, U.S. Army Corps of Engineers] ]Recent developments
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 considered [Kenwood Press, Kenwood, Ca., "New tax considered for Sonoma Creek flood projects", Page 1, volume XVII, no. 10, June 1, 2006] by 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 inflood control , hydrology modeling studies, stream conservation work, including erosion control andwildlife 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 ofSonoma Valley as well as overly intensiveagriculture ,groundwater supplies have been drawn down to the point of causing deleterious effects [Kenwood Press, "Groundwater management study approved", Volume XVII, Number 12, page 1, July 1, 2006] . TheU.S. Geological Survey has found in theCarneros 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.ee also
*
California slender salamander
*List of rivers in California
*List of watercourses in the San Francisco Bay Area References
External links
* [http://www.napa-sonoma-marsh.org/ Napa Sonoma Marsh Restoration Project]
* [http://www.sonomamarinrcds.org/district-ssc/area/sonoma.html Southern Sonoma County Resource Conservation District Watershed Overview]
* [http://www.parks.ca.gov/?page_id=481 Sugarloaf Ridge State Park]
* [http://www.mobilegeographics.com:81/locations/5955.htm Tidal Variations at Mouth of Sonoma Creek]
* [http://sonomacreek.info/ Sonoma Creek]
* [http://waterdata.usgs.gov/nwis/uv/?site_no=11458500&PARAmeter_cd=00065,00060,00062,72020 real-time measurements]
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