Editing Sonoma County, California (section)

===Ocean, bays, rivers and streams===
[[File:Sonoma coastline from Bodega Head-L1001155.jpg|thumb|Typical Sonoma County coastline as seen from Bodega Head]]
Sonoma County is bounded on the west by the Pacific Ocean, and has {{convert|76|mi|km}} of coastline. The major coastal hydrographic features are [[Bodega Bay]], the mouth of the Russian River, and the mouth of the [[Gualala River]], at the border with [[Mendocino County]]. All of the county's beaches were listed as among the cleanest in the state in 2010.<ref name="dirty">{{cite news|url=https://www.sfgate.com/bayarea/article/Bay-Area-beaches-grade-well-for-safe-swimming-3187113.php |title=Bay Area beaches grade well for safe swimming |date=May 27, 2010 |author=Carolyn Jones |newspaper=San Francisco Chronicle}}</ref>

Six of the county's nine cities, from Healdsburg south through Santa Rosa to Rohnert Park and Cotati, are in the Santa Rosa Plain. The northern Plain drains directly to the Russian River, or to a tributary; the southern Plain drains to the Russian River via the [[Laguna de Santa Rosa]].

====Russian River====
[[File:Russian River mouth on California coast.jpeg|thumb|[[Goat Rock Beach]] as viewed from the Jenner Cliffs looking south, showing the [[estuary|mouth]] of the [[Russian River (California)|Russian River]] at the Pacific Ocean]]
Much of central and northern Sonoma County is in the watershed of the Russian River and its tributaries. The river rises in the coastal mountains of Mendocino County, north of the city of [[Ukiah, California|Ukiah]], and flows into [[Lake Mendocino]], a major flood control reservoir. The river flows south from the lake through Mendocino to Sonoma County, paralleled by Highway 101. It turns west at Healdsburg, receiving water from [[Lake Sonoma]] via [[Dry Creek (Sonoma County, California)|Dry Creek]], and empties into the Pacific Ocean at [[Jenner, California|Jenner]].

====Laguna de Santa Rosa====
The Laguna de Santa Rosa is the largest tributary of the Russian River.<ref>{{cite web |url=http://www.lagunafoundation.org/about_ecology.htm |archive-url=https://web.archive.org/web/20110722010816/http://www.lagunafoundation.org/about_ecology.htm |url-status=dead |archive-date=July 22, 2011 |title=The Ecology of the Laguna de Santa Rosa |website=lagunafoundation.org |publisher=Laguna de Santa Rosa Foundation |access-date=July 17, 2014 }}</ref> It is {{convert|14|mi|km}} long, running north from Cotati to the Russian River near Forestville. Its flood plain is more than {{convert|7,500|acre|km2}}. It drains a {{convert|254|sqmi|km2|adj=on}} watershed, including most of the Santa Rosa Plain.

The Laguna de Santa Rosa Foundation says:<ref>{{cite web|url=http://www.lagunadesantarosa.org/ecology.html |website=lagunadesantarosa.org |title=Ecology |publisher=Laguna de Santa Rosa Foundation |url-status=dead |archive-url=https://web.archive.org/web/20070206161535/http://www.lagunadesantarosa.org/ecology.html |archive-date=February 6, 2007 }}</ref>

<blockquote>The Laguna de Santa Rosa is Sonoma County's richest area of wildlife habitat, and the most biologically diverse region of Sonoma County (itself the second-most biologically diverse county in California)... It is a unique ecological system covering more than {{convert|30,000|acre|km2}} and {{sic|comprised|hide=y|of}} a mosaic of creeks, open water, perennial marshes, seasonal wetlands, riparian forests, oak woodlands, and grasslands... As the receiving water of a watershed where most of the county's human population lives, it is a landscape feature of critical importance to Sonoma County's water quality, flood control, and biodiversity.</blockquote>

The Laguna's largest tributary is [[Santa Rosa Creek]], which runs through Santa Rosa. Its major tributaries are [[Brush Creek (Sonoma County, California)|Brush Creek]], Mark West Creek, [[Matanzas Creek]], [[Spring Creek (Sonoma County, California)|Spring Creek]], and [[Piner Creek]]. Santa Rosa Creek was shown to be polluted in Sonoma county first flush results.<ref>{{Cite web|url=https://www.govtech.com/em/disaster/Damage-to-Creeks-Water-Supply-Analyzed-After-Sonoma-County-Fires.html|title=Damage to Creeks, Water Supply Analyzed After Sonoma County Fires|date=2017|website=www.govtech.com|language=en|access-date=March 18, 2019}}</ref>

====Other water bodies====
The boundary with [[Marin County, California|Marin County]] runs from the mouth of the [[Estero Americano]] at [[Bodega Bay]], up Americano Creek, then overland to [[San Antonio Creek (Marin County, California)|San Antonio Creek]] and down the Petaluma River to its mouth at the northwest corner of [[San Pablo Bay]], which adjoins [[San Francisco Bay]]. The southern edge of Sonoma County comprises the northern shore of San Pablo Bay between the Marin County border at the Petaluma River and the border with Solano County at [[Sonoma Creek]]. Sonoma County has no incorporated communities directly on the shore of San Pablo Bay.

The Petaluma River, [[Tolay Creek]], and Sonoma Creek enter the bay at the county's southernmost tip. The intertidal zone where they join the bay is the vast [[Napa Sonoma Marsh]].

[[Americano Creek]], the Petaluma River, Tolay Creek, and Sonoma Creek are the principal streams draining the southern portion of the county. The Sonoma Valley is drained by Sonoma Creek, whose major tributaries are [[Yulupa Creek]], [[Graham Creek (Sonoma County, California)|Graham Creek]], [[Calabazas Creek]], Schell Creek, and [[Carriger Creek]]; [[Arroyo Seco Creek]] is a tributary to Schell Creek. Other creeks include Foss, Felta, and Mill.

Lakes and reservoirs in the county include Lake Sonoma, [[Tolay Lake]], [[Lake Ilsanjo]], [[Santa Rosa Creek Reservoir]], [[Lake Ralphine]], and [[Fountaingrove Lake]].