Southeast California regional basin study released

Study evaluates options to resolve water supply and demand imbalances within the Borrego, Coachella and Imperial Valleys in Calif.

WASHINGTON, D.C., Dec. 15, 2015 -- The Bureau of Reclamation today released the Southeast California Regional Basin Study, which evaluates options to resolve water supply and demand imbalances within the Borrego, Coachella and Imperial Valleys in southeastern California in the face of uncertainty due to climate change. The basin study is among the latest of a West-wide series of studies produced by Reclamation and non-federal partners and comes on the eve of a scheduled White House Roundtable on Water Innovation where Secretary of the Interior Sally Jewell will join other senior Obama Administration officials and several private sector investors to discuss how to plan, effectively use and develop new clean water supplies to ensure our nation’s resilience to water supply shortages.

"Reclamation and its partner on the Southeast California Regional Basin Study are confronting the growing water supply and demand imbalances facing the region," Reclamation Commissioner Estevan López said. "Identifying the issues throughout this basin will help develop potential solutions to ensure the region has a sustainable water supply."

The study found that the Borrego subarea aquifer, which is recharged solely by groundwater, may be depleted in 50 years. Moreover, options to import and store water in the Borrego Valley groundwater basin are not economically viable at this time.

In the Imperial Valley, water users are dependent on imported Colorado River water. Historic climate data and modeling indicate dry conditions may become more frequent with longer durations. Climate change impacts may reduce the snowpack and precipitation leading to a reduced water supply, and can lead to more agricultural water demand as the growing season may become longer. Population is expected to double in the Imperial Valley within the next 40 years with water demand nearly doubling.

In the Coachella Valley, water users are dependent on a mix of groundwater and imported water from the Colorado River. The Coachella Valley Water District has addressed the overdraft of groundwater in its 2010 Coachella Valley Water Management Plan but is facing issues similar to those of the Imperial Valley related to Colorado River water supplies. Population is expected to almost triple by 2045, and though agricultural demand may decline by 45 percent, total demand is expected to increase.

The study evaluated structural and non-structural alternatives that addressed implementing a managed groundwater system in the Borrego Valley, adding pipeline infrastructure to connect Borrego Valley with either Coachella Valley or Imperial Valley, and using existing infrastructure to bank Colorado River water off-stream.

Reclamation partnered with the Borrego Water District to develop the Southeast California Regional Basin Study. The Coachella Valley Water District, Imperial Irrigation District, San Diego County Water Authority and other interested regional stakeholders also contributed to it.

The report is available at

The Basin Study Program is part of the WaterSMART Program. WaterSMART is the Department of the Interior's sustainable water initiative that uses the best available science to improve water conservation and help water resource managers identify strategies to narrow the gap between supply and demand.

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