| Petaluma River | |
|---|---|
 The river flowing through Petaluma. View is to the southeast. | |
 Petaluma River watershed (Interactive map) | |
| Etymology | Coast Miwok |
| Location | |
| Country | United States |
| State | California |
| Region | Sonoma and Marin counties |
| City | Petaluma, California |
| Physical characteristics | |
| Source | |
| • location | 1.5 mi (2 km) southwest of Cotati, California |
| • coordinates | 38°18′18″N 122°43′3″W / 38.30500°N 122.71750°W[1] |
| • elevation | 332 ft (101 m) |
| Mouth | San Pablo Bay |
• location | 5 mi (8 km) east of Novato, California |
• coordinates | 38°6′38″N 122°29′15″W / 38.11056°N 122.48750°W[1] |
• elevation | 0 ft (0 m) |
| Length | 18 mi (29 km)[1] |
| Basin size | 370 km² (140 sq. miles) |
| Discharge | |
| • location | Petaluma (USGS gage station 11459000) |
| • average | 17 cu ft/s (0.48 m3/s) |
| • minimum | 0 cu ft/s (0 m3/s) |
| • maximum | 9,620 cu ft/s (272 m3/s) |
| Basin features | |
| Tributaries | |
| • left | Lichau Creek, Lynch Creek, Washington Creek, Adobe Creek |
| • right | San Antonio Creek |
The Petaluma River is a river in the California counties of Sonoma and Marin[1] that becomes a tidal slough for most of its length. The headwaters are in the area southwest of Cotati. The flow is generally southward through Petaluma's old town, where the waterway becomes navigable, and then flows another 10 mi (16 km) through tidal marshes before emptying into the northwest corner of San Pablo Bay.