The San Joaquin River is one of the two major rivers of California, in the United States. At 330 miles (530 km) long, it is the second longest river in California, after the Sacramento River.[1] It begins on the west Sierra Nevada Mountains and flows west and north to its end at San Francisco Bay, at the Sacramento-San Joaquin Delta. Its basin, which is about 32,000 square miles (82,879 square kilometers) in size, contains mostly farmland. The river provides drinking water to over 22 million California citizens. Its three largest tributaries are the Merced, Tuolumne, and Stanislaus rivers.[2]
The river was once one of the richest river ecosystems in California. However, now over 60 miles (97 km) of the river is dry except during floods, because lots of water has been taken away for irrigation. In fact, below Friant Dam, a dam built in the 1940s on the San Joaquin River, 95 percent of the river's flow is dry. Much of the river is polluted, destroying the historic population of chinook salmon, once the southernmost in the United States. Pesticides, selenium, and many more toxic materials are carried by the San Joaquin into San Francisco Bay.[2]
Now, one of the largest projects in the American West has been begun to restore the San Joaquin River. On September 13, 2006, the Natural Resources Defense Council signed an agreement with Friant Dam users and the United States Department of the Interior. This agreement would restore the San Joaquin River below the dam, reducing pollution.[2]