Located in an extremely arid region, the Salton Sea is subject to high temperatures and low precipitation. Extreme evaporation alone causes the water level at the Sea to decrease 5.4 ft. every year [1]. Historically, the majority of the water inflows at the Sea have been from diversions of the Colorado River, inputs from Mexico, and agricultural discharges from Imperial, Coachella, and Mexicali Valleys. Without these vital inflows, the depth of the Sea will quickly decrease causing release of contaminants currently present at the bottom of the lake and increase in salinity to even higher levels. The current salinity at the Sea is about 54 g/L which is much higher than the salinity in the ocean which is on average 35 g/L. This high level of salinity will affect the habitability for fish at the lake where only tilapia species have been able to survive despite massive die offs.

Currently, the water allocations pertinent to the Salton Sea and the Colorado River are experiencing some changes due to reductions in California’s allocation of Colorado River water. As a result of the Quantification Settlement Agreement (QSA) signed in 2003, by 2017 California is being forced to reduce its import of Colorado River water to 4.4 million acre-feet per year. The QSA was the result of historic disputes regarding the priority, use and transfer of Colorado River water among different agencies across a number of different states including California, Nevada, and Arizona. The QSA has a primary goal to settle water allocation disputes between Coachella Valley Water District and Metropolitan Water District of Southern California [2].

Since agriculture is being impacted due to these changes in water allocations, inflow at the Sea from this source will be greatly impacted, potentially causing even greater decreases in the lake’s water level. Despite this, it has been recognized that the Sea cannot be left on its own and there have been efforts to provide support to the Sea. For instance, under guidelines of the QSA, the Imperial Irrigation District (IID) adopted a 15-year support plan that would allocate water to the Sea giving time for restoration efforts to be developed. IID has implemented fallowing of land to deviate water for San Diego County Water Authority. The profit that IID receives from selling water to San Diego has been partially allocated to the Salton Sea. In 2006, $2 million of that profit was used for the generation of mitigation water for the Salton Sea [3].

This forced reduction of California’s dependency on imported water has created an internal stress within the state and has forced authorities to look for water conservation solutions. With an increased concern about potable water scarcity it is understandable that continuing to divert Colorado River Water into the Salton Sea does not make much sense. This of course, without taking into consideration the major health risks associated with the exposure to dust from the Sea as it dries.

With the current water allocation disputes, soon ending support from IID, and restoration plans still in the works, the Salton Sea is in a tough spot. Without substantial water inflows into the Sea its depth will very rapidly decline resulting in increasing salinity and the release of toxic compounds due to dust from the dry sea bed. In order to avoid the catastrophic consequences of allowing the Sea to dry, the pertinent water authorities need to expand the incorporation of the Salton Sea in future water allocation plans.

Written by Miguel Garcia


[1] Farnsworth, R.K., E.S. Thompson & E. L. Peck, 1982. Evaporation atlas for the contiguous 48 United States: National Oceanographic and Atmos. Adm. Technical Rep. NWS 33. Washington, D.C. National Weather Service.

[2] Quantification Settlement Agreement and Related Agreements and Documents. October 10, 2003.

[3] Quantification Settlement Agreement. Annual Implementation Report 2006. Imperial Irrigation District/ San Diego Water Authority. Water Conservation and Transfer Agreement.