An array of different proposals has been made in the interest of restoring the Salton Sea. While some offer
solutions for single issues facing the Basin, scientists and researchers hope to adopt a more complete plan that
will encompass all five of the current restoration goals. Regardless of which alternative or combination of
alternatives are put into action, it will be important to "maintain the Sea as a repository for agricultural
drainage, provide a safe environment for birds and endangered species, restore the recreational uses of the Sea,
maintain a viable sport fishery, enhance the Sea to provide economic development", and stabilize the water's
salinity level.
A summary of past proposed solutions are listed below For more information on the solutions and the pros and cons
of each, see the "Alternatives" section of the online Salton
Sea Atlas.
For the status of the current proposal visit the Sea Ecosystem Restoration Program web site.
Pumping Alternatives
Several proposals to reduce the Sea's salinity have involved pumping the hypersaline saltwater from the Salton Sea
to the ocean or other nearby dry basins. By pumping saltier Sea water out, and replacing that water with ocean
water, the salinity of the Sea would eventually approach that of ocean water.
People have been using solar evaporation ponds to concentrate salts since the dawn of civilization. Solar
ponds work by removing concentrated salts from Sea water relative to fresher inflows. By itself, solar evaporation
would require moving approximately 100,000 acre-feet of water to the ponds to remove the amount of salt that
enters the Sea each year, requiring approximately 40 square kilometers (15 square miles) of solar ponds in
shallow areas in or near the Sea.
Nutrient Removal
One of the primary problems at the Salton Sea is the eutrophic character of the lake's ecosystem, fueled by
nutrients from agricultural drainage and municipal wastewater. Several alternatives are being explored to remove
nutrients from the three tributary rivers to the Sea.
Enhanced Evaporation Systems fall into one of two varieties: the first are essentially giant snow blowers that
take seawater and vaporize it, causing more rapid concentration of salts than by natural evaporation alone;
the second are tower-based, in which the water is pumped to the top of one tower and bled through lines extending
between two towers. EES may be implemented in conjunction with solar ponds for more efficient salt removal, in which
the salt is dredged out of the EES system and discarded directly into a disposal pond.
The “Salton Sea Habitat Enhancement Project”, proposed by the Pacific Institute for Studies in Development, Environment, and Security, calls for construction of dikes at the north and south ends of the Salton Sea to retain freshwater flows from the Alamo, New and Whitewater Rivers. Two dike configurations were analyzed, involving both ten- and fifteen-feet high dikes at the south end of the Sea, and a ten-foot high dike at the north end of the Sea, just offshore from the mouth of the Whitewater River. The project could be implemented in conjunction with the development of constructed treatment wetlands along the Alamo and New Rivers to control sediment entering the system and could also be designed using other management practices to reduce nutrient loads from agricultural and municipal wastewater sources.
The Salton River proposal, put forth by the private water filtration company, U.S. Filter, calls for creation of a shallow water dike, collecting the New and Alamo River flows from the south and directing them north along the eastern side of the Salton Sea in the form of the man-made “Salton River”. The Salton River would deliver 77% of the Sea’s natural inflow to a desalination plant at the north end via a ten- or fifteen-feet deep diked impoundment, with a surface water design elevation of -230 feet. The desalination plant could produce as much as 500,000 acre-feet of water for export. The brine effluent would then be discharged to a river running back down along the western shore to the south, eventually draining to a brine pool in the center of the basin. The intent is to transform the saltwater marine habitat of the Sea to a freshwater, riverine habitat of similar biologic productivity, while freeing up 500,000 acre-feet of water for transfer. Depending upon the ten- or fifteen-feet deep dike configurations and the level of assumed ongoing inflow, the result of exporting 500,000 acre-feet of water from the basin would create 21,000-40,000 acres of riverine surface area, exposing 84,000 to 136,000 acres of lake bottom sediments, and leaving a brine pool of 58,000 to 129,000 acres in the middle of the two sub-basins.
Regional Water Quality Control Board Alternatives
In response to a variety of issues brought up by the Salton River proposal discussions, the California State Regional Water Quality Control Board (RWQCB) proposed two variations. These proposals used the idea of a Salton River and desalination, but also included construction of a mid-sea dike to maintain a marine habitat in the north basin, and siting the desalination plant at the south end of the Sea, with the south basin used for brine disposal. The project would reclaim approximately 700,000 acre-feet of water for reuse on Imperial Valley farms. These two proposals used the concept of the Salton River, but varied on the length and position of the dikes as well as the size and depth of the north lake. The first variation proposed to build a river structure around the entire perimeter of the Sea while maintaining the north basin at an average depth of approximately 7 feet. The second variation proposed to build a river structure around the south basin with a larger north lake, maintaining an average depth of approximately 27 feet. Both proposals call for a number of habitat enhancements including pupfish refugia and freshwater marshes.
The Salton Sea Integrated Water Management Plan utilizes elements from all of the other alternatives in an attempt to maximize the use of water flowing into the Sea. The proposal would maintain a marine lake environment in the north basin sustained by desalinated water delivered through a river extending along the perimeter of the south basin. The river, as proposed, would be maintained at the current shoreline elevation with depths ranging from 10 to 15 feet deep, but would remain sufficiently saline so as to not require vegetation removal. The north lake would be maintained at an elevation of 230 feet below sea level and at a salinity equivalent to that of the ocean. The plan calls for as much as 500,000 acre-feet of water to be reclaimed for use on Imperial Valley farms. Outflow from the north lake would flow along a channel to the southwest, spreading water through a series of shallow, one- to two-feet deep cells, doubling as shorebird habitat, before draining to a brine disposal pool in the South Basin. The plan opens up previously flooded areas for expansion of geothermal energy development. This resource has the potential to provide 25% of the State of California’s current electrical power need for 30 years once fully developed. This resource could provide a major stimulus to the economy of the Imperial Valley and more than compensate for any fallowing or loss of water to the region.
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