Map of key rivers, creeks, channels and washes in Los Angeles County. Los Angeles Almanac map.
Click on map image above for larger image.
Besides its three key rivers, Los Angeles County also has a number of creeks, channels and washes that feed into the rivers. For most of the year, almost all carry little to no water. It is during the rains of winter when these see fast-moving waterflow. The Los Angeles and San Gabriel Rivers and most of their branches have been channeled and mostly lined with concrete channel walls to prevent flooding during heavy rains. Some effort, however, has been made to restore some of the natural appearance of portions of the Los Angeles River. The Santa Clara River remains one of the few unchanneled, fully natural rivers in Southern California.
| River | Length (miles) | Drainage Area (square miles) | Source | Mouth |
|---|---|---|---|---|
| Los Angeles River | 51 | 834 | Canoga Park, Los Angeles | Pacific Ocean at Long Beach |
| San Gabriel River | 58 | 590 | East Fork San Gabriel River, Angeles National Forest | Pacific Ocean, Long Beach/Seal Beach |
| Santa Clara River | 84 | 1,029* | Acton, Angeles National Forest | Pacific Ocean at Oxnard, Ventura County |
* 786 square miles within Los Angeles County, 243 square miles within Ventura County
Source: Los Angeles County Department of Public Works
Channelization of Los Angeles County rivers began in 1938 and ended in 1954.
