STRATEGIES FOR THE
RESTORATION AND ENHANCEMENT
4.4 Alternative 3: Fresh Water Shoreline/Pumped Storage
This approach (Figure 7) combines 12 possible components:
1. A fresh water area around the north shoreline of the Sea would be created by means of a dike approximately 1 mile out from and parallel to the current shoreline. The Whitewater River would empty into this impoundment through a constructed wetlands area. The saline water in the impoundment area would be replaced with fresh water, most probably obtained from the Coachella Canal. This fresh water area could be managed for recreation, a fresh water fishery, and as habitat for waterfowl and other species.
2. 1,000 acres of constructed wetlands would be constructed at the mouth of the Whitewater River. This would provide for additional wildlife habitat along the shore-line of the Sea as well as help to filter the water entering the fresh water enhanced shore-line area.
3. 75,000 ac-ft of water from agriculture return and other runoff would be filtered through the constructed wetlands and used for the creation of a fresh water recreation area, fishery and waterfowl habitat.
4. A pumped storage facility would be constructed on the northeast side of the Sea with a holding pond atop a nearby hill. Water from the impoundment area would be pumped into the holding pond during the evening hours when electricity rates are low, and allowed to flow back to the fresh water impoundment area during the day to generate up to 500 MW of hydroelectric energy.
5. A desalination plant would be constructed and utilized to convert approximately 100,000 ac-ft of Salton Sea water to fresh water. This created fresh water could be mixed with Whitewater River water and agricultural return water and used to increase the water quality of the north shoreline fresh water enhancement area.
6. Up to 200,000 ac-ft per year of the blended, desalinized water from the fresh water shore-line area could be pumped to the Coachella Canal and sold to water purveyors as a revenue source.
7. A solar pond power plant, without an enhanced evaporation system, could be constructed along the southeast shore of the Sea. This area could be sized to remove approximately 150,000 ac-ft/year for 10 years. In combination with the desalization plant it would bring the salinity in the Sea from 45,000 to 35,000 p.p.m. in 10 years. A 16,000 acre solar pond power plant facility, would generate 1,500 megawatts of power, creating an additional revenue source. A companion salt disposal area of 6,000 acres would dispose of salt for 40 to 50 years after the initial 10 years salt concentration period.
8. 6,000 acres of wildlife habitat could be constructed in a dike system that would reclaim areas along the south shore of the Sea.
9. The reclaimed land along the southern shore-line would include two areas, totaling 5,000 acres, of constructed wetlands to help improve water quality in the New River and Alamo Rivers as they enter the Sea.
10. Reclaimed land would be used for agriculture or habitat creation. The agriculture land could be sold or leased and the habitat could be sold as mitigation credits.
11. An additional 300,000 ac-ft of water could be conserved in the Imperial and Coachella Valleys with the implementation of this plan. This water could then be sold to urban users to help finance Salton Sea improvements.
12. As a later option, the 500 MW pumped storage facility to the Gulf of California could be created at the southwest shore of the Sea. If it was unfeasible to construct this facility then this area could be used as a salt disposal area.
4.4.1 Benefits of this Alternative
a. SalinityThis alternative combines several approaches for reducing the salinity of the Sea: (1) creating a salt concentration area within the Sea itself, (2) a desalination plant, and (3) a solar pond energy plant.
b. Surface Elevation StabilizationThe construction of diked areas would be used to reduce the overall size of the Sea, compensating for withdrawals of water for other purposes, and stabilizing the Sea at a desired elevation.
c. Pollutant ControlConstructed wetlands would filter pollutants and remove excess nutrients. Approaches to remedy high concentrations of selenium, such as those described in Section 4.1.1 (c), might still be needed if selenium could not be adequately controlled through constructed wetlands.
d. Additional Benefits
- The freshwater areas at the northern end would create habitat, fishery, and recreational opportunities. With the pumping and power generation operation, this area would actually be tidal once a day, potentially enhancing the habitat values. A double lock system could connect this area to the main part of the Sea to allow ingress and egress of boats without any fresh water/salt water exchange.
- Up to 500 megawatts of power could be generated from the pumped storage facility. This creates useful peaking energy and capacity and a revenue stream to help offset costs. If demonstrated to be economically feasible, the solar power plant could also be constructed as a separate element.
- Desalinized water could be mixed with Whitewater River water and sold to water purveyors. When combined with additional conservation the water sold could total 500,000 ac-ft each year.
- Storm water run-off could be captured in the diked areas. This captured water could then be channeled into the Sea to help with salinity reduction and/or elevation stabilization, or sold for additional revenue.
- Stabilization of the surface elevation would create new development opportunities by eliminating the threat of inundation.
- If constructed wetlands were a part of this alternative, the habitat could be established as a mitigation bank and credits sold. Similarly, if wetlands were created in the diked areas, mitigation credits might be sold.
4.4.2 Issues Requiring Additional Consideration
Issues requiring further study include potential environmental impacts, market demand for the energy produced, and demand for water harvested for sale.
4.4.3 Long Term Management
As stated before, in looking beyond solving existing problems to creating new opportunities, the Authority should consider working with affected agencies and interests to develop more complete goals and objectives for the Salton Sea before implementing any remediation actions to enable the Authority to evaluate remediation alternatives in the context of longer term goals and objectives, and to identify opportunities created by the rehabilitation of the Sea and the best strategies for capitalizing on them.
Alternative # 3 Fresh Water Shoreline/Pumped Storage