| Pinole Creek | |
|---|---|
 | |
 | |
| Location | |
| Country | United States |
| State | California |
| Region | Contra Costa County |
| City | Pinole, California |
| Physical characteristics | |
| Source | Briones Hills |
| • location | 6 mi (10 km) west ofPleasant Hill, California |
| • coordinates | 37°57′3″N122°9′34″W / 37.95083°N 122.15944°W /37.95083; -122.15944[1] |
| • elevation | 1,090 ft (330 m) |
| Mouth | Chelsea Wetlands,San Pablo Bay |
• location | Hercules |
• coordinates | 38°0′51″N122°17′48″W / 38.01417°N 122.29667°W /38.01417; -122.29667[1] |
• elevation | 7 ft (2.1 m)[1] |
| Basin features | |
| Tributaries | |
| • left | Duncan Creek |
| • right | North Creek, Fana Creek |
Pinole Creek is astream in westernContra Costa County, in theEast Bay region of theSan Francisco Bay Area,California.
The creek has one of the last primarily undeveloped watersheds in the Bay Area.[2]
Theheadwaters of Pinole Creek are in theBriones Hills on Costa Peak, within the western area ofBriones Regional Park. It flows 10 miles (16 km) westerly through the towns ofPinole andEl Sobrante,[3] to itsriver mouth at theChelsea Wetlands inHercules onSan Pablo Bay. Its mouth is 4 miles (6.4 km) east ofPoint Pinole.[4]
The namePinole is from the Spanish term for "parched corn", which the Mexicans ground for eating.[4] In 1823, aMexican land grant for 17,000 acres (69 km2) that included Pinole Creek was granted to Don Ignacio Martinez, a Commandant of theSan Francisco Presidio. The land grant was initially known asEl Rancho de La Nuestra Sonora de Merced, and later renamedRancho El Pinole. Martinez built the first adobe in Pinole Valley and brought his family to settle the property with livestock and orchards.[5]
The upper watershed contains large areas of open space and managed grazing lands, with ranching and agricultural activities, and residential equestrian properties. The lower watershed contains the historic Old Town District ofPinole, and suburban neighborhoods in Pinole,El Sobrante, andHercules. The watershed follows the regional geologic northwest–southeast orientation, similar to the orientation of theBerkeley Hills, and is located just northeast of the Sobrante Ridge.
The watershed is approximately 39.6 square miles (103 km2) in area, extending from headwaters on Costa and Duarte Peaks in theBriones Hills, northwest to theSan Pablo Bay just east of Wilson Point. The average annual rainfall for the Pinole Creek watershed is 610 mm (24 in), with 90% falling between November and April. There are twelve minor, locally named tributaries and the gradient is 1%.[2]
In 1965, theArmy Corps of Engineers armored the creek channel betweenInterstate 80 and San Pablo Bay for flood control. However, this removedriparian zone vegetation and tree cover needed for food, shelter, and shade for fish and other wildlife.[5]
Biologists from theEast Bay Municipal Utility District (EBMUD) have observedSteelhead trout (Oncorhyncus mykiss) in the Pinole Creek watershed of multiple ages. Genetic studies by EBMUD in 1999 suggest that the trout are native Central California stock and not introduced.[5] Perennial flows are jeopardized by water usage in the upper watershed but the creek may have the best trout restoration potential in the East Bay because large portions of the watershed are in open space. However, the I-80 crossing may be a significant obstacle to upstream trout migration.[6]
Pinole Creek supports a mostly native fish assemblage including rainbow/steelhead trout,California roach (Lavinia symmetricus), Sacramento sucker (Catostomus occidentalis),Threespine stickleback (Gasterosteus aculeatus), Prickly sculpin (Cottus asper).Mosquitofish (Gambusia affinis) andCommon carp (Cyprinus carpio) are nonnative fishes found predominantly in the lower section of Pinole Creek, below Interstate 80.[5]
Native plants are species of theCalifornia chaparral and woodlands andriparian forest habitats. Invasive plant species such asGiant reed (Arundo donax),Scotch broom (Cytisus scoparius),Yellow star thistle (Centaurea solstitialis),Himalayan blackberry (Rubus discolor) and many others are established alongriparian zone sections of Pinole Creek.
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