California

Background: Average annual rainfall - 200-500mm 65% of precipitation is lost to evaporation and transpiration 50% of California's rain falls between November and March Reasons for Insecurity: Spatial Imbalance - 3/4 of demand comes from the south - most rain falls in the north State Water Project - 20 dams and reservoirs irrigating 0.3 million hectares of farmland, providing drinking water for 20 million people Central Valley Project - 22 dams and reservoirs irrigating 0.2 million hectares of farmland, providing drinking water for 2 million people Colarado River - 11 dams and reservoirs irrigating 1.4 million hectares of farmland, providing drinking water for 25 million people Rainfall declining since the 1980s Uses 90 billion gallons a year to water 900 golf courses 5.3 million acre-feet of water to irrigate pasture for beef herds

Impacts of Scarcity: Tensions between north and south over who owns water Lake Mead and Colarado River drying up Poorly maintained leevees and river banks along Feuther River allowed salty water to submerge islands Endangered fish Less water for irrigation

Solutions to Insecurity: Domestic conservation - repairing leaks and using smart sprinkler systems Groundwater Banks - saving storm water for dry periods Re-using waste water - cleaned water from sewage plants could be reused for irrigation Reducing agricultural usage - new housing development only built new adequate water supplies Sharing the Colarado

Impacts of Solutions: Housing with adequate water supplies Saving and reusing water

Conflict and Tensions:In 1901 the Alamo Canal began to bring water from the Colarado to Californian farmers however political tensions with Mexico (through the canal ran) meant the supply was not guaranteed

CALFED Delta Bay Programme:Aims to reduce conflict by developing a sustainable, long term solution to water management and environmental problems. CALFEDs aims are; provide reliable good quality water supplies ecosystem restoration improve leevees and protect delta islands increase water storage improve water conveyance guarantee farmers supplies maintain dissolved oxygen levels to preserve fish and the wetland ecosystem