1.1 Purpose of Commissioning a White PaperIn 1993, the Counties of Riverside and Imperial, the Imperial Irrigation District and the Coachella Valley Water District joined forces to create the Salton Sea Authority. According to the Joint Powers Agreement creating the Salton Sea Authority, the purpose of the Authority is "to create a public agency to exercise the common power of directing and coordinating actions relating to improvement of water quality and stabilization of water elevation and to enhance recreational and economic development potential of the Salton Sea and other beneficial uses, recognizing the importance of the Salton Sea for the continuation of the dynamic agricultural economy in Imperial and Riverside Counties."
Riverside County and Coachella Valley Water District retained Dangermond & Associates, for the Salton Sea Authority, to review solutions previously proposed for various problems affecting the Sea and explore new possibilities and combinations of possibilities which might either reduce costs, generate revenues, or create access to new funding sources. This resulting white paper suggests three alternatives which incorporate portions of previously proposed solutions with several new concepts, and evaluates funding strategies and sources, including revenue generating aspects of the solutions, for each. In so doing, this white paper, only generally, identifies concepts and potentials for further study; it is beyond the scope of this preliminary analysis to consider all of the environmental, jurisdictional, economic, and technological factors which will affect the ultimate feasibility of a solution.
1.2 The IssuesThree primary issues have been previously identified by the many agencies and interests concerned with the Salton Sea: salinity, elevation, and pollutants. Because these issues have been well described in the Salton Sea Symposium "Technical Presentation Summaries" and elsewhere, they are only briefly summarized here:
Inflow of salt into the Sea is about 4,000,000 tons per year, principally from agricultural run-off. With no outlet, the Sea's salinity concentrates steadily through evaporation. At present, the level of Total Dissolved Solids (TDS) is about 45,000 milligrams per liter (mg/L) compared to the TDS level of the ocean of about 35,000 mg/L. The rate of increase in salinity for the Sea has recently been about 700 mg/L/year. Reproduction of fish may be adversely affected at current levels, and the fish population is expected to undergo a rapid decline as salinity increases further. Recreation and associated economic values will be impacted, as will wildlife values as aquatic food sources decline and the food web is disrupted.
Historically, the elevation of the Sea has been subject to significant change depending on the level of inflow from agricultural run-off and storm flows. In the first two decades after the Sea's creation in 1905 - 1907, the elevation declined rapidly. Increased agricultural development in the watershed then caused a steady rise in elevation, except during a period of reduced irrigation water availability from 1931 - 1935. Changing elevation over the years has flooded some developments and wildlife habitat. In recent years a balance between agricultural flows and evaporation has created a relatively stable elevation, although the seasonal fluctuation between spring and fall ranges between approximately 1 and 2 feet. In the future, water conservation measures, and efforts to reduce salinity could reduce the elevation to a lower than desirable level. The effect of siltation on elevation over time is not known.
Selenium levels in the Sea have captured considerable attention in recent years because of the threat posed to wildlife and the fishery. Studies have identified Colorado River water as the primary source of selenium; as it is used for agricultural purposes, the selenium level concentrates before entering the Sea. In the Sea, selenium appears to be selectively removed, possibly through concentration in bottom sediment and/or by the volatilization of selenium by selenate-respiring bacteria. Selenium levels in fish are somewhat elevated and a public health advisory warning has been issued to limit fish consumption as a precautionary measure. Studies to date have indicated that while breeding birds have been exposed to elevated levels of selenium, the risk of reproductive toxicity is low; however, the most recent tissue studies of eared grebes indicate a significant increase in recent years. Also, selenium may affect birds by weakening their immune systems at levels less than that which cause reproductive toxicity. Elevated levels of a number of heavy metals, organochlorine pesticides, and organic solvents have also been detected in the Sea, but the impact on biota in the Sea has not been fully studied. Nutrient loading of the Sea with nitrogen and phosphorus from agricultural run-off has made the Sea highly productive biologically, but has also contributed to algae blooms which, at times, creates unpleasant odors and discoloration of the water, and may cause localized depletion of oxygen leading to fish kills.
1.3 The ProcessTo prepare this white paper, Dangermond & Associates assembled a team which includes expertise in environmental issues (Jones & Stokes) engineering (Woodward Clyde), water reclamation (Bill Dendy), and energy (Energy National), as well as planning and economic expertise provided by Dangermond & Associates. The team met for an initial brainstorming meeting to identify preliminary ideas and information needs. Dangermond & Associates then met with a variety of agencies and interests to gather information and explore some of the preliminary concepts. This information was shared with the entire team which then conducted a two day workshop to complete the development of conceptual solutions to the Salton Sea problems and the evaluation of funding strategies and sources. This white paper presents the team's findings.