4.3 Alternative 2: Pumped Storage/Gulf Salt Disposal
This approach Figure 6 combines two main components:
1. A storage facility and power generation plant
2.A large canal/pipeline linking the Salton Sea with the Gulf of California.In essence, an enormous pumped storage facility would be created utilizing two vast bodies of water: the Salton Sea and the Pacific Ocean. The canal/pipeline would carry water pumped from the Salton Sea to the Laguna Salada; from there it could flow to the Gulf of California through an improved channel. Salton Sea water would be pumped at night when electricity rates are lower. During the day, water would flow from the Gulf of California back to a storage area at the highest point of elevation between the Gulf and the Sea, and then used to generate hydroelectric power as it descends to the Salton Sea. The volume of water pumped each day would depend on the size of the power plant, however, even with a 500 megawatt plant, the elevation of the Sea would fluctuate less than 1 inch.
Since the Salton Sea's elevation presently fluctuates between spring and fall, the amount pumped could vary as well. A monthly cycle could be established with extra water pumped each day from the Sea for two weeks, and then extra power generated for two weeks as more water would be brought from the Gulf of California to the Salton Sea. This would allow the Sea to fluctuate about one foot a month, while exchanging the total volume of the Sea every few years. Functionally, at least to an extent, the Sea would become an extension of the Gulf. The connection would be accomplished with a canal approximately one fourth of a mile wide following the sea level contour and terminating at the Superstition Hills.
4.3.1 Benefits of this Alternative
a. SalinityThe gradual exchange of water between the Salton Sea and the Gulf of California would stabilize the salinity of the Sea at the level of the Gulf in less than 10 years. (The difference between the present salinity and that of the ocean would drop approximately 20% each year.)
b. Surface Elevation StabilizationBy regulating the amount of water pumped out of and into the Sea, the surface elevation of the Sea could be maintained at a desired level with a high degree of precision.
c. Pollutant ControlThe exchange of water with the Gulf would effectively dilute the concentration of nutrients and pollutants in the Salton Sea. If it were determined that introducing the nutrients and pollutants from the Salton Sea into the Gulf would have an adverse impact, constructed wetlands could be utilized to clean up agricultural run-off and other non-Gulf water flowing into the Sea. This would minimize, though not wholly eliminate, the introduction of pollutants and excess nutrients into the Gulf. Approaches to remedy high concentrations of selenium, such as those described in Section 4.1.1 (c), would probably still be needed if selenium could not be adequately controlled through constructed wetlands.
d. Additional Benefits
- From 500 to 800 megawatts of power could be generated. This creates useful energy and a revenue stream to help offset costs.
- Stabilization of the surface elevation would create new property development and land value enhancement 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.
- The issue of long term disposal of salt is eliminated.
4.3.2 Issues Requiring Additional Consideration
Issues requiring further study include international jurisdictional issues, potential environmental impacts from the canal and to the Gulf ecosystem, and market demand for the energy produced.
4.3.3 Long Term Management
As was discussed earlier, in exploring ways to address the major threats to the Sea, it is important to also think about the opportunities which are created for long term management. 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. Development of a comprehensive plan would 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. Accompanying environmental documents would provide a sound basis for decision-making and might function as a program EIR for later project specific planning.
Alternative # 2 Salton Sea/Gulf of California Water Exchange