The San Joaquin River

The San Joaquin River cuts through the enormous Central Valley in the heart of California. Coursing over 300 miles from headwaters in the Sierra Nevadas to its mouth at the Sacramento-San Joaquin Delta, the river basin covers a large swath of California.

The river passes through a range of different California climates. Its origin is at around 14,000 feet up in the mountains. Here, snowfall is heavy through the winter. As the river begins draining down the mountain, it passes through areas where the average precipitation is 35 inches per year. By the time the river crosses the valley floor, it is in much drier climates. Average precipitation drops to 6.5 to 22 inches, and the temperatures rise.

The river's course through the San Joaquin Valley provides a ready source for irrigation. In the valley, a few other rivers also originating in the Sierra Nevadas flow into the San Joaquin River. Were it not for the San Joaquin River and its tributaries, one of California's largest farming areas might not exist. The climate in the valley is hot and dry in the summer. Although the winters can be moist and foggy, the San Joaquin Valley contains about two million acres of agricultural land that must be irrigated.

The Friant Dam was built on the river in 1942 to control flooding, prevent saltwater damage to the Sacramento-San Joaquin Delta, and provide water for irrigation. Many people enjoy recreational water activities on Millerton Lake, the lake created by the dam. But a group of people protested the dam not long after it was finished. The people said that the building of the dam had affected the salmon spawning sites below the dam. In 1992, Congress passed the Central Valley Project Improvement Act (CVPIA), which made many improvements to the protection of wildlife areas on land and in the water.

In recent years, increased efforts have been made to preserve and restore wetlands and other native habitats in the valley. Several national wildlife refuges and wildlife areas have been formed in the river region. These lands supply resting places for migrating birds, preserve historic floodplains for the San Joaquin River, and provide homes for a large number of animals and plants. Many of the wildlife areas are in the process of having more land added to their refuges.

Balancing the demands of the San Joaquin River and its basin will require attention and cooperation in the years to come. People will have to figure out how to continue protecting and caring for natural wildlife areas while ensuring that the needs of farmers are also met.

Vocabulary

irrigate:: To supply (dry land) with water by means of ditches, pipes, or streams; to water artificially.
spawning:: Producing offspring.
tributary:: A river or stream feeding into a major river.

Sources:

San Joaquin River Parkway and Conservation Trust: http://www.riverparkway.org/
Central Valley Project - Friant Division: http://www.usbr.gov/dataweb/html/friant.html
California Water Plan Update 2005 San Joaquin Hydrologic Region: http://www.waterplan.water.ca.gov/docs/cwpu2005/vol3/v3ch07.pdf
Central Valley Project Improvement Act (CVPIA): http://www.usbr.gov/mp/cvpia/