The Colorado River’s Salty Tears: Evaluating the Yuma Desalination Plant
In the face of reduced Colorado River flows, thirsty Basin states race to squeeze every drop from the arid West. According to the University of Colorado Western Water Assessment, climate change is expected to decrease the Colorado River’s flow by as much as 20 percent very soon (Smithsonian, 2010). One controversial water reclamation option recently considered and tested by the Bureau of Reclamation is the Yuma Desalination Plant (YDP).
Pros: The YDP has the potential to reclaim 108,000 acre-feet of saline drainage water from the Wellton-Mohawk Irrigation and Drainage District each year at an estimated cost of $322-$556 per acre-foot (Bureau of Reclamation, 2008). If the Bureau operates the YDP, Wellton-Mohawk drainage water will flow back into the Colorado River instead of into the Cienega de Santa Clara, as it has for the past 34 years. This desalination and diversion would allow the Wellton-Mohawk drainage water to count towards Mexico’s 1.5 million acre-feet allotment.
Cons: The YDP is predicted to cause reduced flow to and increased salinity in the Cienega, thereby threatening the wetland and its wildlife. The Cienega is an ecologically diverse 15,000-acre wetland habitat, home to several threatened and endangered species such as the Yuma Clapper Rail and the Desert Pupfish. Operation of the desalination plant is predicted to significantly reduce the size of the wetland and increase salinity levels upwards of 7,000 ppm total dissolved salts (TDS). The Cienega’s typha stands, which lose viability in waters above 5,000 ppm, TDS constitute the Yuma Clapper Rail’s primary habitat. The U.S. Fish and Wildlife Service claims that it can delist the Yuma Clapper Rail with the stabilization of a water supply to the Cienega.
An Alternative: In addition to the YDP, the Bureau of Reclamation has looked into other water development options. A voluntary forbearance program to pay farmers to fallow a portion of their fields could provide water at an estimated cost of $60-$150 per acre-foot, which is substantially cheaper than the estimated cost of the YDP. This strategy would allow water to continue to flow to the Cienega (Bureau of Reclamation, 2005). Potential drawbacks of this plan include a loss of both agricultural production and revenue for farming communities.
Further Information:
A timeline of the history of the Yuma:
http://www.usbr.gov/lc/yuma/about_us/yao_history.html
A presentation on the feasibility of using the Yuma Desalination Plant:
http://www.usbr.gov/lc/region/programs/bypass/Oct2005presentation.pdf
Further information on the alternatives to using the Yuma Plant:
http://www.usbr.gov/lc/region/programs/bypass/history.html