| Petaluma River | |
| river | |
|
The river flowing through Petaluma. View is to the southeast.
|
|
| Name origin: Coast Miwok | |
| Country | United States |
|---|---|
| State | California |
| Region | Sonoma and Marin counties |
| Tributaries | |
| - left | Lichau Creek, Lynch Creek, Washington Creek, Adobe Creek |
| - right | San Antonio Creek |
| City | Petaluma, California |
| Source | |
| - location | 1.5 mi (2 km) southwest of Cotati, California |
| - elevation | 332 ft (101 m) |
| - coordinates | [1] |
| Mouth | San Pablo Bay |
| - location | 5 mi (8 km) east of Novato, California |
| - elevation | 0 ft (0 m) |
| - coordinates | [1] |
| Length | 18 mi (29 km) [1] |
| Discharge | for Petaluma (USGS gage station 11459000) [2] |
| - average | 17 cu ft/s (0 m3/s) |
| - max | 9,620 cu ft/s (272 m3/s) |
| - min | 0 cu ft/s (0 m3/s) |
The Petaluma River is a river in the California counties of Sonoma and Marin[1] that becomes a tidal slough near its mouth. It springs from farmlands southwest of Cotati and flows generally southward through Petaluma's old town and 10 mi (16 km) of tidal marshes to end in northwest San Pablo Bay.
Contents |
The word Petaluma, may derive from the Miwok words pe’ta, flat, and luma, back. The Miwok people lived in Sonoma County for more than 2500 years. Petaluma was the name of a village on a low hill east of Petaluma creek and north east of the present day town of Petaluma. The first recorded exploration of the Petaluma River was by Captain Fernando Quiros in October, 1776. While other members of his Spanish expedition collected adobe and timber for the new Presidio of San Francisco and for the Mission San Francisco de Asís (Mission Dolores), Quiros and his sailors tried unsuccessfully to sail from San Pablo Bay to Bodega Bay.[3]
Located in southern Sonoma County, California, and a portion of northeastern Marin, the Petaluma River Watershed drains 146 square miles (380 km2).[4] The watershed is approximately 19 miles (31 km) long and 13 miles (21 km) wide with the City of Petaluma near its center. At 2,295 feet (700 m), Sonoma Mountain is the highest point in the watershed, and its western slopes drain to the Petaluma River by way of tributaries such as Lichau Creek, Lynch Creek, Washington Creek, and Adobe Creek. The lower 12 miles (19 km) of the Petaluma River flow through the Petaluma Marsh, the largest remaining salt marsh in San Pablo Bay. The marsh covers 5,000 acres (20 km2) and is surrounded by approximately 7,000 acres (28 km2) of reclaimed wetlands.[4] In the marshes west of Lakeville, the river is joined by San Antonio Creek, at which point it becomes the boundary between Marin County and Sonoma County. The river flows under State Route 37 at Green Point and enters northwest San Pablo Bay just north of Petaluma Point.
While the river's source lies over 300 ft (100 m) above sea level, it descends to 50 ft (15 m) within about 0.4 mi (600 m). The river is fully tidal 11 mi (18 km) from its mouth, indicating its slight gradient through the marshes below Petaluma. The United States Army Corps of Engineers dredges this section to keep it navigable by gravel barges and pleasure craft.
The Petaluma River Watershed hosts several federally endangered animals including the Salt marsh harvest mouse (Reithrodontomys raviventris), Peregrine Falcon (Falco peregrinus anatum), California Clapper Rail (Rallus longirostris obsoletus), Winter-Run Chinook salmon (Oncorhynchus tshawytscha). Endangered flora include Soft Bird’s-Beak (Cordylanthus mollis ssp. mollis), Baker’s Stickyseed (Blennosperma bakeri), Burke’s Goldfields (Lasthenia burkei), Showy Indian clover (Trifolium amoenum), Sebastopol meadowfoam (Limnanthes vinculans).[4]
The Steelhead trout (Oncorhyncus mykiss) that spawn and rear in the Petaluma River watershed are wild, not hatchery, stock.[5] Chinook are seen in the main stem of the Petaluma River and The United Anglers of Casa Grande High School have seen chinook at the turning basin, near the Lynch Creek confluence. The high school students constructed a salmonid hatchery in 1993[6] and in 2002 74 Chinook salmon returned to spawn in the Adobe Creek tributary.[7]
The marshes provide an important wildlife habitat and fish hatchery. However, since the onset of intensive European immigration in the mid-1850s, the water quality has diminished, partly due to overgrazing and other agricultural uses. Pollutants present in the river include nitrates, phosphates, petroleum hydrocarbons, pesticides and sediment.[8] Urban runoff, particularly from the City of Petaluma, adds heavy metals and hydrocarbons to the river.[9] Starting about 1990, material steps were taken to mitigate the pollution. However, continuing population growth makes it difficult to attain the State of California's water quality goals.
Bridges span the Petaluma River at the following locations: State Route 37, U.S. 101, Corona Road, Petaluma Boulevard North, and four places in Petaluma (D Street, Payran Street, Washington Street, and Lakeville Street). The longest of these, the 4-lane State Route 37 bridge, is 2,183 ft (665 m) long and was built in 1958. The oldest bridge, built in 1925, is a 114 ft (35 m) concrete triple span carrying two lanes of Petaluma Boulevard North.[10]