Peripheral Canal
The Peripheral Canal was a proposal to divert water from California's Sacramento River, around the periphery of the San Joaquin-Sacramento River Delta. The canal attempted to resolve a problem created by pumps that create such a powerful suction the boundary between freshwater to saltwater has shifted inland, negatively affecting the environment. The pumps have increased by 5 to 7 million acre feet (6.2 to 8.6 km3) the amount of water exported each year to the Central Valley and Southern California. The peripheral canal as proposed would have reduced the overall freshwater flow into the Delta and move the freshwater-saltwater interface further inland, causing damage to Delta agriculture and ecosystems.
Before the Central Valley Project and State Water Project were built, all freshwater—primarily runoff from the Sierra Nevada—entering the Sacramento–San Joaquin River Delta flowed into San Francisco Bay. After the pumps powering the Central Valley Project and State Water Project became operational, the freshwater was drawn from the Delta Cross Channel through a maze of river channels and sloughs before entering the Clifton Court Forebay north of Tracy, where water is pumped into the California Aqueduct and the Delta-Mendota Canal. Large numbers of Delta smelt and other endangered species are killed by the pumping plants, which provide water for the aqueducts. Freshwater flowing into the Delta displaces salt water entering from the San Francisco Bay.
Senator Dianne Feinstein, former California Governor Arnold Schwarzenegger and Governor Jerry Brown supported the Peripheral Canal. However, the Peripheral Canal proposal was criticized because it would further reduce the amount of freshwater flowing through the Delta. Farmers in the Delta are among the most opposed to the project because it would decrease the amount of water available to them for irrigation. On August 28, 2014 the United States Environmental Protection Agency commented that the plan could violate the Clean Water Act and harm endangered fish species.
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