The Salton Sea is located in southern California and is considered the largest inland water body in the state. The Salton Sea was formed in 1905 when the Colorado River broke through a canal gate, allowing water to flow into the Salton Basin uninterrupted for 18 months. Since its formation, the Sea has been maintained largely through agricultural runoff from surrounding areas. The Salton Sea was not the first body of water in the basin; several other lakes have existed in the Basin throughout its geological history. The creation of the Salton Sea in 1905 eventually led to development of its shoreline and its waters were stocked with sportfish. Until the late 1960s, the Salton Sea was one of the most prolific sport fisheries in the country, with a high diversity of birds and wildlife. The Salton Sea also serves as an important wetland area along the Pacific Flyway, a migratory route for birds stretching from Alaska to Patagonia. The ecology and economy surrounding the Salton Sea has deteriorated steadily over the past several decades due, in part, to a changing ecosystem marked by decreasing water flows and increasing salinity. The Salton Sea has shrunk due to evaporation and declining water inflows, resulting in increased salinity and deteriorating fish and wildlife habitat. High salinity levels combined with toxic concentrations of substances have led to disease and widespread mortality of fish and birds. Current saline levels are nearing fatal levels for all fish, leading some scientists to predict that fatal saline levels will occur by 2018. The subsequent population decline of fish could have severe effects on migratory birds that use the Salton Sea as a primary stopover point on the Pacific Flyway. Furthermore, exposed lake beds could allow toxins and dust to enter the air, which could lead to air pollution and human health problems. Attention to the ecological condition of the Salton Sea and efforts to restore the Sea have existed for several decades. However, interest in the ecological health of the Salton Sea has amplified since 2003, when the Quantification Settlement Agreement (QSA) was signed by several water districts in California, the state of California, and the Department of the Interior (DOI), and signed into California law. QSA requires California to gradually reduce its consumption of Colorado River water to 4.4 million acre-feet a year (AFY) through voluntary agriculture-to-urban water transfers and other water efficiency measures. The implementation of this agreement has resulted in less water flowing into the Salton Sea, thus accelerating its ecological decline. However, as part of the QSA, participating water districts agreed to contribute $163 million toward mitigation and restoration. In addition, the water districts agreed to provide 200,000 AFY of Colorado River water to the Sea though December 31, 2017. While some of these mitigation efforts have been implemented, longer-term restoration efforts and the distribution of these costs are still contested and uncertain. Congressional concern for restoring the Salton Sea stems, in part, from the value of the Sea as habitat for federal and state listed endangered species, as well as other migrating and resident bird species; a reservoir for agricultural drainage waters; a center for recreation; and a large wetland ecosystem, among other things. Concerns over air pollution from exposed sea beds have also been expressed by Members of Congress. These concerns have been reflected, in part, by efforts to address the restoration of the Salton Sea and its ecosystem. Congress has passed laws addressing the restoration of the Salton Sea and authorized funds for restoring the Salton Sea in the Water Resources Development Act of 2007. Current restoration efforts have been led mainly by the state and local governments. Consensus around restoring the Salton Sea has not been fully attained. Some contend that the Salton Sea should not be restored. They argue that the geological history of the Salton Sea demonstrates a pattern of water bodies naturally shrinking and disappearing, and then reforming over time. They note that the Salton Sea will follow a similar process and that countering this natural process will be costly and ultimately not worth the cost. These opponents argue that the restoration funds should instead be used to restore other natural wetlands in California, such as the Sacramento and San Joaquin rivers' delta confluence with San Francisco Bay (Bay-Delta). To counter this argument, some respond by noting that the natural inflows of water into the Salton Sea have been artificially diverted by humans when the Colorado River was diverted into a canal and that natural processes and cycles will not exist again with these structures in place. Further, they note that the value of restoring the Salton Sea lies in its ecological significance as a large wetland along the Pacific Flyway and a habitat for fish and wildlife, and its potential to stimulate economic development in the region through tourism, recreation, and energy development. The Salton Sea is located in southern California and is considered the largest inland water body in the state. The Salton Basin, where the Salton Sea is located, has supported many lakes and water bodies throughout its geological history. The last of these prehistoric water bodies was Lake Cahuilla, which dried up nearly 400 years ago. In 1901, a portion of the Colorado River was diverted through the Imperial canal to irrigate agricultural fields in the Salton Basin. Water flowed through the New Alamo River and into the Imperial Valley from this channel. In 1905, water from spring floods broke through a canal head-gate diverting a portion of the Colorado River into the Basin and forming the Salton Sea. Water flowed uninterrupted for nearly 18 months into the Salton Sea before it could be redirected to the Gulf of California. The new Sea formed as a closed basin with no outlets, which is still its condition today. The Sea consisted largely of fresh water at its inception; however, the water immediately began to evaporate and increase in salinity. The construction of Hoover Dam and the All American Canal in 1928 allowed water from the Colorado River to be transferred directly to the Imperial Valley for irrigation. After flowing through agricultural lands, this water drained into the Salton Sea, thereby preventing the Sea from evaporating. In 1924 and 1928, President Coolidge executed Public Water Reserve Orders 90 and 114 for the withdrawal of lands located in and around the Salton Sea. These lands were designated as a repository for agricultural, subsurface, and surface water drainage. The ecosystem properties of the Salton Sea are largely determined by its water level, chemical and salt concentration, and balance between the rate of evaporation and water inflow. Nearly 75% of the water flowing into the Sea comes from agricultural runoff originating in the Imperial and Coachella valleys in California, the other 25% is from rain and other surface inflows. As water in the Sea evaporates, the concentration of salt increases. Presently, the salinity level in the Sea is approximately 52 parts per thousand (ppt), which is approximately 50% greater than ocean water and one-fifth that of the Great Salt Lake in Utah (270 ppt) (See Figure 2 ). At 52 ppt, the Salton Sea is considered to be hypersaline. High salinity combines with extreme eutrophication to cause fish kills in the Sea. Eutrophication can result in anoxic conditions leading to fish death. In 1950, the Sea reached salinity levels similar to the Pacific Ocean. At this time, the California Department of Fish and Game began transferring saltwater fish species to the Sea. During the 1950s, and in the next two decades, the Sea became a popular destination for sport fishing and tourism. However, changes to the Sea, including flooding of resort areas and wildlife habitat, bird and fish die-offs, and health threats of untreated water, led to a decline in recreation and development around the Sea in the 1960s. The current salinity levels in the Sea are too high to support the former diversity of fish. The most ubiquitous species in the Salton Sea now is the tilapia ( Oreochromis mossambicus ), which was introduced by farmers to control weeds in their ponds in 1964. In addition, the Sea also houses the endangered desert pupfish ( Cyprinodon macularius ), the only native fish species in the Sea. Deteriorating water quality has also had a large detrimental impact on the invertebrate life in the Sea, such as on pileworms and barnacles, two important components of the Salton Sea food web. Currently, few fish can survive in the hypersaline waters of the Sea. Future salinity predictions indicate that all species of fish may disappear from the Sea as early as 2023. The Salton Sea ecosystem provides a variety of habitat for fish and wildlife species, including open water, estuaries, salt marshes, and riparian corridors. Due to the loss of wetland habitat in southern California and throughout the state's vast Central Valley, the Salton Sea is a primary stopover point for birds on the Pacific Flyway. The Sea supports more than 400 species of resident and migratory birds, of which more than 50 are species of special status (including three listed under the Endangered Species Act (ESA)). Surveys have estimated that the total population of birds in the Salton Sea can reach up to 500,000 birds per month. Many of these birds are piscivorous, relying on fish in the Salton Sea for sustenance. Other birds can feed on both the fish and invertebrates found in the basin. The mortality of bird and fish species in and around the Salton Sea is of concern because of federal and state listed endangered species that inhabit the Sea. For example, the Yuma clapper rail ( Rallus longirostris yumanensis ) is a federally listed endangered species, residing in and around the Sea during the year. Other state listed species of special interest, such as the peregrine falcon ( Falco peregrinus ) and the bald eagle ( Haliaeetus leucocephalus ), are occasionally seen at the Sea as they make their way along the Pacific Flyway. The desert pupfish ( Cyprinodon macularius ) is the only endemic fish species in the Salton Basin, and was listed as a federally endangered species in 1986. Conserving endangered species in the Salton Basin is one of the objectives of the Salton Sea Authority, which was chartered by the State of California in 1993 to remedy problems facing the Salton Sea. The Salton Sea Authority is a "joint powers" agency chartered to ensure the beneficial uses of the Salton Sea, such as maintaining the Sea as an agricultural drainage reservoir, restoring the wildlife resources and habitats around and in the Sea, stimulating recreational use, and providing an environment for economic development around the Sea. This agency is comprised of representatives from Riverside and Imperial counties, the Coachella Valley Water District, the Imperial Irrigation District, and the Torres Martinez Desert Cahuilla Tribe. Federal and state agencies have representatives on the Authority as ex-officio members. Farmlands in the Imperial and Coachella valleys have historically been irrigated with approximately 3.3 million AFY of Colorado River water. From this amount, the Salton Sea received approximately 1.4 million AFY of this water in the form of agricultural runoff. However, under the Quantification Settlement Agreement (QSA), which was passed in October 2003, around 300,000 AFY of Colorado River water that flows from these valleys are being supplied to other urban water districts and not all reaching the Salton Sea. (See below for a summary of the QSA.) These agriculture-to-urban transfers will reduce agricultural inflows to the Sea by an estimated 30% by 2018, according to stakeholders. The Bureau of Reclamation modeled flow changes after 2018 with the implementation of the QSA and determined that 95% of all future inflows would less than or equal to 835,000 AFY between 2018 and 2077, with a mean of all inflows equaling 727,000 AFY. The Salton Sea Authority estimated a relatively similar scenario, where water flowing to the Salton Sea would stabilize at 800,000 AFY after 2018 with the implementation of the QSA (see Figure 3 ). The QSA contains multiple provisions to mitigate environmental effects of its implementation on the Salton Sea, including the following: IID is to directly transport 200,000 AFY of Colorado River water to the Salton Sea for 15 years from 2003 to January 1, 2018. IID, CVWD, and SDCWA are to provide $133 million for environmental mitigation related to the water transfers, and for IID to deposit an additional $30 million into a restoration fund. The State of California is to assume all additional costs of mitigation and restoration. The legality of this cost provision was recently upheld. Concurrent legislation also set up a Salton Sea Restoration Fund (SSRF), overseen by the Department of Fish and Game to be used for environmental and engineering projects (Fish and Game Code Section 2931). The California Secretary for Resources, in consultation with the Salton Sea Authority, was to present the state legislature with a preferred alternative restoration plan for the Salton Sea by December 31, 2006. In addition, this legislation stated that restoration of the Salton Sea was of state and national interest; it authorized the state to develop a long-term, adaptive conservation and restoration plan for species in the Salton Sea. However, the development and implementation of any restoration plan is conditional on the state legislature appropriating funds and not required by the QSA. The California Secretary for Resources was required to present the state legislature with a preferred alternative restoration plan, but there is no requirement to implement or fund this preferred alternative. Some have used this premise to assert that there is no unconditional obligation for the State of California to develop and implement a long-term restoration plan that would aim to restore the Sea to a previous state that could support the fish and migratory birds that currently reside and visit there (for a visual representation of mitigation versus restoration impacts in salinity, see Figure 4 ). There is still disagreement on the extent to which the state is responsible for restoration. Some contend that the recent state court ruling established that the QSA requires the state to restore the Salton Sea. However, in recent QSA litigation, IID and CVWD have argued that actual Salton Sea restoration was never a commitment by the state. The state legislation implementing the QSA requires IID, CVWD, SDCWA, and the State of California to fund the costs of environmental mitigation deemed necessary to avoid environmental harm due to the water transfers. The Environmental Impact Assessment determined that appropriate mitigation could be met by 200,000 AFY of Colorado River water transferred annually to the Salton Sea for the first 15 years after water transfers commenced; the construction of a pupfish refugium pond and the development of a plan to provide pupfish connectivity between drains; up to 652 acres, and at least 190 acres, of managed marsh for rail birds; two roost sites for brown pelicans; monitoring programs for all state and federally listed species; and a study program to determine the impacts of selenium on wildlife. IID, CVWD, and SDCWA, were required to pay up to $133 million of these environmental mitigation costs, with the state required to pay any and all additional costs, regardless of legislative appropriations. IID, CVWD, and SDCWA also agreed to place $30 million into the Salton Sea Restoration Fund (SSRF). Some contend that the most pressing issue for the Salton Sea is increasingly high salinity. Some experts state that, without intervention, the Salton Sea will reach fatal salinity levels for most aquatic wildlife in the Sea between 2018 and 2028. Scientists have predicted that the Salton Sea could exceed 60 ppt by 2018 after the water transfers under the Quantitative Settlement Agreement (QSA) ramp up and mitigation water transfers to the Sea end. According to some, salinity levels beyond 40 ppt might result in fish with limited reproductive success, suppressed immune systems, and physiological stress. At 60 ppt and above, the water would be too saline to support tilapia, the main food source for birds in the area. Some contend that the Salton Sea would have naturally increased in salinity over time, thereby reducing its ability to sustain aquatic wildlife. Others describe increasing salinity in the Sea as predominately a result of human activities (e.g. water transfers and agriculture), which have decreased the potential for restoration. Other water quality issues, such as toxic chemicals and low oxygen levels, are also directly related, in part, to diminishing water flows. Toxic levels of selenium and elevated levels of Dichlorodiphenyldichloroethylene (DDE) have been found in the Sea. These substances have been detected at toxic levels in fish and wildlife in and around the Sea. Both DDE and selenium can cause reproductive problems in fish and birds. In addition, DDE and selenium can have adverse health effects on humans. Some contend that toxic levels of these substances were attained due to agricultural areas being the main source of water inflows to the Sea. There were widely publicized mortalities of fish and birds in and around the Salton Sea in the 1990s thought to be associated with toxins. In 1996, an estimated 15% to 20% of the western population of white pelicans and more than 1,000 endangered brown pelicans died. In August 1999, more than 7.6 million tilapia and croakers died due to low levels of dissolved oxygen in the Sea. Water quality issues have raised concerns about the future of endangered species that depend on the Salton Sea ecosystem. The loss of fish populations in the Sea could significantly reduce and possibly eliminate use of the Salton Sea by piscivorous birds by the early 2020s, according to some scientists. Some state and federally listed piscivorous birds such as the Yuma clapper rail (federal and state endangered) could be affected initially. Some invertebrates and possibly desert pupfish could survive at higher salinity levels, according to some scientists. For example, desert pupfish have survived in waters with salinity as high as 90 ppt in various locations. Some birds that rely on both fish and invertebrates may still be able to forage under high salinity conditions; however, the species composition of birds would be expected to change as the makeup of invertebrates shifts due to changes in salinity. Some nonnative fish species might still be found in the Salton Basin in areas of lower salinity around the Salton Sea, such as the rivers, creeks, and agricultural drains that feed into the Sea. Air pollution may emerge as an environmental issue as the Salton Sea shrinks in size. As the shoreline recedes, areas of lake bed would be exposed to heat and wind. As the lake bed dries and erodes, dust could enter the air and be circulated across large areas. Air-borne dust from dry beds in the Sea could contain harmful levels of pesticides, herbicides, and naturally occurring selenium. People in the surrounding Coachella and Imperial counties could be affected by this contaminated dust and contract respiratory problems. Presently, some counties near the Salton Sea have significantly higher rates of respiratory problems compared to other nearby counties. While there are many possible causes for these increased numbers of respiratory issues around the Salton Sea area, some attribute the problems, in part, to contaminated air derived from dry areas around the Salton Sea. Some also note that salt in the dust upwelling from dry areas around the Sea can damage crops. The Pacific Institute has estimated that the loss of water due to water transfers will expose an additional 130 square miles of seabed and increase the amount of dust in the air by a third over what is currently found. The Salton Sea Authority estimates that if the Sea dries up, the cost to mitigate the effects of dust alone will be upwards of $1 billion, with annual maintenance cost of around $48 million. In the fall of 2012, a strong southern wind stirred the Salton Sea waters, bringing decayed material to the surface. This released hydrogen sulfide and produced a very strong rancid odor that was reported more than 200 miles away in both Simi Valley and Los Angeles County. This incident was dubbed the "Big Stink" and captured the attention of national media outlets. After this incident, funds were allocated to install monitoring equipment to measure gases rising from the sea. While there are no known human health concerns linked to the odorous gases, the incident stimulated attention about the poor condition of the Salton Sea, according to some. Further, the hydrogen sulfide released from the Sea (the source of the smell) consumes oxygen in Sea waters. This could result in fish kills, and if severe enough, could deplete all the oxygen in the Sea and cause the ecosystem to collapse. Some of the ecological problems in the Salton Sea were foreseen by scientists who noted that salinity in the Sea was increasing at a rate that would eventually render the Sea uninhabitable for fish and wildlife. Early studies focused on understanding the hydrological and saline properties of the Sea. Since then, several federal, state, and private entities have developed proposals to restore the Sea, primarily by controlling its salinity and maintaining its water level. Federal efforts to restore the Salton Sea can be traced to the passage of the Reclamation Projects Authorization and Adjustment Act of 1992 (Title XI, §1101 of P.L. 102-575 ). The act directed the Secretary of the Interior to conduct research on projects to control salinity levels, provide habitat for endangered species, enhance fisheries, and protect recreational values in the Salton Sea. Seven years later, authorized restoration activities in the Salton Sea expanded with the passage of the Salton Sea Recovery Act of 1998 ( P.L. 105-372 ). This act authorized the Secretary of the Interior to conduct feasibility studies and economic analyses of various options for restoring the Salton Sea. Further, the secretary was authorized to conduct studies of wildlife and species' responses to the hydrology and toxicology of the Sea. This act also authorized river reclamation activities for the New and Alamo Rivers (tributaries that flow into the Salton Sea). In addition, several restoration projects have been administered through the state-funded Salton Sea Authority, including efforts in collaboration with the U.S. Bureau of Reclamation (BOR). Early restoration work conducted by both state and federal entities consisted of feasibility studies focused on solar pools and salt evaporation technology. Both of these approaches aim to reduce the salinity of the Salton Sea by evaporating a portion of the seawater and disposing resulting salt deposits. To maintain a steady sea level, water from the Colorado River would need to flow into and mix with the Salton Sea. In 2004, the Salton Sea Authority released a restoration plan for the Salton Sea that called for the construction of a causeway across the center of the Sea. This was eventually incorporated into the 2006 Salton Sea Authority Plan for Multi-Purpose Project . The plan proposed to split the Salton Sea into two pools. However, when the QSA was first upheld by court in 2007, some suggested that the acquisition of water from the Colorado River necessary for salinity control technologies would be physically and politically infeasible. In its study analyzing options for restoring the Salton Sea, the Secretary of the Interior was not authorized to consider any option that relies on importing new or additional water from the Colorado River. Restoration activities and studies regarding the Salton Sea have been mainly funded and managed by the State of California. The state has increasingly endorsed the use of Saline Habitat Complexes (SHCs) to maintain viable ecosystems for current wildlife. These complexes would be constructed with berms or other barriers to create shallow saline pools. The salinity in these pools could vary and would be maintained by 'blended water', or possibly geothermal-powered desalinated Salton seawater. State efforts to restore the Salton Sea are, in part, due to provisions in the QSA which require the California Secretary for Resources, in consultation with the SSA, to present the state legislature with a preferred alternative for restoration. This state-identified preferred alternative was published as the Salton Sea Ecosystem Restoration Final Programmatic Environmental Impact Report (PEIR) and presented to the legislature in May of 2007. The state-identified preferred alternative included SHCs in the northern and southern end of the Sea, a marine sea formed by barriers, air quality management facilities, a brine sink for discharge of salts, conveyance facilities, and sedimentation distribution facilities. In addition, the preferred alternative included Early Start Habitat, areas for geothermal development, and connectivity waterways for desert pupfish (See Figure 5 for the plan). The final cost for the state preferred alternative is estimated at $8.9 billion (in 2006 dollars). After construction is completed, the expected annual operations and maintenance costs are $142 million (in 2006 dollars). No state action has been taken to authorize funding for this plan. However, the state is proceeding to implement pilot studies that measure the effectiveness of SHCs, with federal assistance. For example, the state has a Salton Sea Species Conservation Habitat Project plan that is nearing completion. The aim of this project is to create up to 3,770 acres of SHCs for conserving and protecting fish and wildlife species that depend upon the Salton Sea. Pools would be created at the southern end of the Salton Sea on land owned by Imperial Irrigation District or the federal government. The project is not intended to be a comprehensive restoration project for the Salton Sea, but rather a "proof of concept" project to see if SHCs along the edge of the Sea can sustain fish and wildlife. The project would affect jurisdictional waters, and thus, requires the U.S. Army Corps of Engineers (Corps) to assess the project and provide necessary permits for construction. The Corps, in conjunction with the state, released a Final Environmental Impact Statement/Environmental Impact Recommendation in July 2013. The Corps is expected to use the EIS/EIR in determining whether to issue a Department of the Army permit for this project under section 404 of the Clean Water Act. In addition to the state-identified plan, the SSA continues to seek funding and support at both the state and federal level for its 2006 plan involving the separation of the Sea into two lakes (see " Restoration Efforts in the Salton Sea " for more details on the SSA Plan). In recent negotiations between IID and County of Imperial, both parties have endorsed the SSA 2006 Plan. The state legislature is addressing Salton Sea issues through legislation. For example, state bill AB71 would require the California Natural Resources Agency, in consultation and coordination with the Salton Sea Authority, to lead Salton Sea restoration efforts. Efforts would include several investigations into restoration projects. Further, the bill would authorize the Salton Sea Authority to lead a restoration and funding study to address restoring the Salton Sea and provide input to the Secretary of the California Natural Resources Agency on various aspects of restoration and air quality in the region. Federal actions directed towards restoring the Salton Sea are not following any comprehensive plan. Restoration efforts by federal agencies are largely in the form of pilot projects, monitoring, and individual agency plans or proposals. For example, BOR created and disseminated a study assessing restoration possibilities in 2007. The development of the study was authorized and required under P.L. 108-361 . Section 201 states that the Secretary of the Interior, in coordination with the State of California and the Salton Sea Authority (SSA), shall complete a feasibility study on a preferred alternative for restoration. The BOR study provided five alternative restoration plans and a no action alternative, with costs for implementing the alternatives ranging from $3.5 billion to $14 billion. BOR did not state a preferred alternative, claiming that the uncertainty and risks, combined with the high costs of all five restoration alternatives prevented it from recommending an alternative. However, given that the no-action alternative had $1.4 billion estimated mitigation costs, BOR emphasized that consideration should be given to the SHCs component described in alternative 5. BOR and USGS created a pilot study consisting of a small series of SHCs from 2006 to 2010 to determine whether these complexes could be a feasible restoration approach. The pilot study concluded that SHCs, and similar saline complexes, could minimize the risks and costs of restoration, while restoring wildlife habitat and partially mitigating air quality impacts. However, selenium concentrations in these pools were reported at potentially toxic levels, which would warrant observation and study to see how it might adversely affect fish and wildlife. Overall, the study was reported to demonstrate that the SHP model is a viable alternative for restoring wetlands at the Salton Sea, but that the potential risks of selenium need to be considered. As noted above, the Corps is also involved in pilot studies concerning SHCs. The Water Resources Development Act of 2007 ( P.L. 110-114 ) authorized the Secretary of the Army to review the state-approved plan, the "Salton Sea Ecosystem Restoration Program Preferred Alternative Report and Funding Plan", and implement feasible pilot projects described in the plan. Under WRDA 2007, if the secretary determines the projects are feasible, then he is authorized to enter into an agreement with the state to help implement the pilot projects. One of these pilot projects is the previously mentioned Salton Sea Species Conservation Habitat Project plan. The Administration has requested $200,000 of federal funding for a reconnaissance study of the plan. The request is in the Corps FY2014 budget request. In addition to proposed comprehensive plans to restore the Salton Sea, several have endorsed site-specific plans or activities for restoration. For example, local and state efforts have been made to fund and explore the development of renewable and biofuel energy sources in the Salton Sea. The Sea has multiple potential renewable energy sources that include geothermal energy, solar power, and bio-algae. It has been estimated that the Salton Sea Basin could support up to 2,000 megawatts (MW) of economically feasible renewable energy capacity. A large portion of this capacity- around 1,400 MW- would be geothermal. The rest would be solar, which some proposed could be constructed along acres of the exposed lake beds around the Sea. Currently, IID generates approximately 600 MW of geothermal energy in the Basin. IID has been developing a pilot study to use geothermal energy to desalinate water to create saline habitat pools. The Torres-Martinez Tribe has also requested funding from the State of California to construct a solar photovoltaic field to power reliable and sustainable water delivery to the saline habitat ponds on its land. If these pilot studies indicate that the use of renewable energy for desalination is feasible, it could allow for previously discussed salinity control methods to be used. The desalinated water could be a substitute for the fresh Colorado River water that would otherwise be necessary for salt evaporation and salinity control in the Basin. In addition, SSA has been discussing a partnership with the Salton Sea Action Committee (SSAC), which represents some of the private business in the area interested in energy development. The SSAC is interested in promoting the development of renewable energy (e.g., solar fields and geothermal) in the Basin to generate funds for restoration. Further, there is discussion about creating an Infrastructure Finance District in the area, which would use a portion of proceeds from development to fund restoration. The SSAC contends that this arrangement would allow local governments to take on infrastructure and other projects (e.g., geothermal and other energy plants) and generate funds necessary for maintaining the Sea for fish and migratory birds. Some others have proposed the production bio-algae as a mechanism to both provide funds for restoration and improve the environmental health of the Salton Sea. Researchers at Clemson University have developed a Controlled Eutrophication Process (CEP) to grow algae in the Sea. Preliminary studies have shown that CEP would improve water quality, increase fish production, and have a potential sizable revenue stream. Progress towards restoring the Salton Sea has been slow in recent years, largely due to the lack of a comprehensive plan to guide efforts and lack of funding. Indeed, some contend that there is not full consensus behind restoring the Sea. Those against restoration contend that it will naturally shrink and disappear, making attempts at restoration futile and expensive in the long term. Others counter these claims by stating the Sea is in an artificial state of decline because of its reliance on agricultural runoff artificially conveyed from the Colorado River. Further, they add that the increasing salinity of the Sea along with its shrinkage will cause irreparable damage to the ecosystem and negatively affect fish and wildlife populations, as well as create health risks for humans due to contaminated dusts. Some contend that the federal government has not taken an active role in physically restoring the Sea. Most federal actions have centered on creating proposals for restoration and conducting pilot studies. Restoration efforts have largely centered on state actions. Congress might consider shifting the federal position to a more active role by authorizing federal restoration actions and providing appropriations to implement them. In contrast, Congress might consider leaving restoration responsibilities to the State of California and allowing the federal government to continue its supporting role. The importance of the decision of how to proceed might amplify as the QSA goes into effect and temporary local mitigation efforts end. The presence of endangered species in the Salton Sea and documented health hazards from the evaporation of the Sea are issues some cite to justify federal action. The following section provides an overview of the issues concerning the federal role in restoring the Salton Sea, and then discusses specific aspects of the federal role and how Congress might address them. Some contend that the federal government should have a greater role in restoring the Salton Sea. They note that the federal government owns 47% of the land underneath the Sea, and federal agencies, such as the Bureau of Land Management, have leased a portion of the land to private entities for oil and natural gas development. They also note that the Salton Sea ecosystem is important for several listed species under the federal ESA and that the Department of the Interior is currently conducting studies to evaluate proposals for restoring the Salton Sea. Others counter this sentiment by noting that there are no laws that authorize direct federal involvement in physically restoring the Sea. (Note that some federal laws authorizing broad restoration actions could be applied to restoring parts of the Salton Sea ecosystem.) Further, they note that the State of California is directly authorized to restore the Sea under state law and that restoration should be a state responsibility. State efforts to restore the Salton Sea ecosystem have largely gone unfunded due to state fiscal concerns, according to some. Some note that if federal funds were available, the construction and development of larger restoration projects could proceed. Due to the expense and estimated costs of currently proposed restoration plans, advocates argue that a combined state and federal effort to restore the Salton Sea would be an appropriately balanced approach to restoration. However, some may contend that an open-ended federal commitment to restore an area with questionable prospects for restoration success may not be the best use of federal resources in a time of fiscal constraint. They contend that other wetland restoration efforts, such as in the San Francisco Bay and Sacramento and San Joaquin Rivers Delta (Bay-Delta) and Lake Tahoe in California would be more cost-effective and efficient ways to address species concerns and restore existing ecosystems. If Congress considers expanding the federal role in restoring the Salton Sea, there are a few factors to consider, including (1) creating authorizing legislation to create a comprehensive plan (or implement an existing plan) and governance structure for restoration; (2) funding existing authorized activities or a new effort at restoration; (3) addressing restoration under ESA; and (4) maintaining the status quo of providing assistance to the State of California. Lastly, Congress might decide not to address restoration in the Salton Sea ecosystem. If Congress chooses not to authorize or fund Salton Sea restoration activities, efforts by the State of California would be the primary avenue for restoration. California is directed under the QSA and the state law to mitigate the effects of the QSA in the Salton Sea. However, even with mitigating the effects of the QSA, habitat loss and salinity is expected to continue. The next sections discuss options for Congress listed above. The Salton Sea does not have a comprehensive plan that is being implemented for restoration. Several entities have released different restoration plans. Many state, tribal, and federal agencies have a stake in the Basin and each has proposed different plans. The current proposed state plan is estimated to cost $8.9 billion. The federal restoration alternatives identified by BOR in 2007 had estimated costs ranging from $3.5 billion to $14 billion. So far, state and federal appropriations have not been provided to support the implementation of any large-scale project. Some private stakeholders have presented smaller-scale versions of the state and federal plans that cut costs by eliminating certain aspects of the plans. These partial restoration plans are estimated to reduce costs by up to 75%. Most of the funding for restoring the Salton Sea, according to some, has been spent on creating plans and monitoring, rather than directly implementing projects. These studies have provided data and highlighted issues and strategies for future restoration projects. However, the short lifespan (most projects are decommissioned within five years) of these efforts may result in limited long-term environmental impacts. Congress might consider increasing the federal role in restoring the Salton Sea by authorizing the creation of a comprehensive restoration plan that would involve federal and state resources and incorporate shared governance, or authorizing an existing proposed restoration plan. For example, restoration in the Greater Florida Everglades is guided by the Comprehensive Everglades Restoration Plan (CERP), which includes 68 projects and has a 1:1 cost share between the federal government and the State of Florida. DOI and the Corps are the primary federal entities involved and the South Florida Water Management District is the non-federal sponsor. Other ecosystem restoration initiatives in areas such as the Chesapeake Bay and Platte River also involve the federal government and one or more states. An alternative to creating and authorizing a comprehensive plan for restoration could be to expand and fund existing federal authorities that contribute toward restoring the Salton Sea. Congress may choose to expand the federal role in the restoration of the Salton Sea by funding existing restoration projects and authorizations aimed at restoration. For example, the Water Resources Development Act of 2007 authorized the Secretary of the Army to review the state plan and determine whether pilot projects in the plan are feasible. If the Secretary decides that the projects are feasible, then he is authorized to enter into an agreement with the state, in consultation with the Salton Sea Authority and the Salton Sea Science Office, to carry out the pilot projects. The non-federal sponsor (e.g., State of California) would pay 35% of the total cost of the project, and the federal government would pay 65%. The law authorizes $30 million for these projects, with no more than $5 million per project. To date, no funding has been authorized for the Corps to carry out these projects; however, the Administration has requested $200,000 for a reconnaissance study on these pilot projects for FY2014. Other federal authorities for addressing restoration in the Salton Sea are primarily for conducting studies to determine if certain restoration methods are feasible. For example, funds authorized by the Salton Sea Reclamation Act of 1998 ( P.L. 105-372 ) are for implementing pilot projects to measure saline habitat pools. BOR received appropriations (and then contracted with USGS) to carry out these pilot studies and have reported generally positive results. Funding has also been used to implement scientific research on the Salton Sea as well as monitoring and collecting data about the state of the Sea. Some programs under ESA could be applied to restoration of habitat and species recovery and used to help fund efforts in the Salton Basin. The Salton Sea is a key stop along the Pacific Flyway, which serves as the migratory route for many endangered and threatened species. The Salton Sea is not currently designated as critical habitat for these species, which has been questioned by some scientists who believe it should be listed as critical habitat along the Flyway. Nearby areas, however, do contain critical habitat and can play a role in restoration. For example, parts of the Imperial Valley, including the Salton Sea, were designated a critical habitat for the desert pupfish. The recovery plan for the desert pupfish states that the few natural habitats and populations remaining should be protected. The incidental take permits granted by the Fish and Wildlife Service for the water transfer authorized under the QSA require that the participating parties maintain desert pupfish habitat connectivity. Further, QSA mitigation requires that desert pupfish habitats be maintained as long as the transfers are occurring and that a detailed management plan be developed when salinity reaches 90 ppt (the point at which desert pupfish can no longer reproduce in the Sea). These requirements might stimulate restoration and maintenance of the Salton Sea or the maintenance of small habitat pools to maintain these endangered species. Possible funding sources through the ESA include appropriations for recovery actions of listed species and the Cooperative Endangered Species Conservation Fund (CESCF). CESCF could benefit species that are listed or proposed for listing under ESA, through grants to states and territories. Funds from CESCF could also be used to help states prepare Habitat Conservation Plans (HCPs). If there are several actors participating in the creation of an HCP, states can use their funds to coordinate the effort and develop a single plan that might cover the region. Some alternative funding mechanisms have been proposed by state, local, and private entities that could involve the federal government. For example, some have proposed the use of renewable energy development in the Basin to help fund restoration. One way to utilize renewable energy would be through public-private partnerships (PPPs). PPPs involve contract arrangements in which a nonfederal or private entity partners with the government to contribute funds, knowledge, or labor toward a project. In return, the private or nonfederal entity is guaranteed a portion of the project's revenue as repayment. The other portion of the revenue could be used to fund public goods such as restoration. Multiple federal agencies have instituted public-private programs to fund and manage restoration. These include the National Oceanic and Atmospheric Administration (NOAA), the U.S. Army Corps of Engineers (Corps), the Bureau of Land Management (BLM), the U.S. Forest Service (USFS), and the Fish and Wildlife Service (FWS), among others. Many of these agencies have programs that provide funding for a project while a private company develops and constructs the project. In several cases, this model also involves cost-sharing between the federal agency and nonfederal entity. According to independent studies commissioned by stakeholders in the area, the Salton Sea Basin has large renewable energy potential. This includes geothermal, solar, and bio-algae energy production. Integrating energy production and PPPs to generate funds for restoration has been suggested by some as a potential alternative to raise revenue and improve the local economy in the Basin. Potential federal entities that could be involved with PPPs in the area include BLM and FWS. However, for PPPs to be viable, they would need to generate revenues with minimal risk to the private entity. Some contend that the barriers to renewable energy development in Salton Sea Basin, such as lack of access to transmission lines, lack of access to water necessary to run generators, and environmental concerns including endangered species and seismic inductions due to the activities, might be prohibitive for energy development in the area. Congress might consider the potential effects of not restoring the Salton Sea in weighing options for action. Most studies and statements by scientists and other stakeholders note that the Sea will shrink in size and increase in salinity without restoration. This is expected to amplify after 2018, which is the expected date for mitigation deliveries to the Salton Sea to stop under the QSA. Some have modeled the future physical characteristics of the Salton Sea without restoration. Without restoration, the present ecosystem would be unable to continue with high salinity concentrations. The migratory birds that visit the Salton Sea would largely disappear from the area. The Salton Basin, however, could still be ecologically productive. For example, the high salinity concentrations would be conducive for brine shrimp, flies, algae, and bacteria. Over time, however, the salinity and oxygen depletion could reach levels that would affect the survival of remaining organisms in the area. While modeling has predicted that the sea size would stabilize around 2040, the salinity would continue to increase. Models estimate that salinity would be 330 ppt by 2075. To put this in perspective, the saltiest portions of the Great Salt Lake in Utah are 270 ppt and the Dead Sea is around 337 ppt. By 2040, an additional 134 square miles of the seabed would be exposed compared to the present size of the Sea. Contaminated dust from these exposed areas could impact the livelihood of the farmers in the surrounding counties and have adverse health effects on those in neighboring communities. Studies have not been able to quantify the economic impacts of increasing dust on the agricultural economy in the area. However, possible impacts include damaged crops and additional water needed to leech salts and toxins from the soil. Many of the business owners in the area have stated that lack of restoration would lead businesses in the area to close. Locals have expressed fears that unemployment would increase if businesses closed. Also, the state and federal governments may bear additional health care costs due to increased health problems. While acknowledging that the Salton Sea ecosystem is undergoing a transition to a smaller and saltier water body, some contend that the natural transition of the Sea should not be interfered with. These opponents of restoration contend that the future Salton Sea will have a new, but equally productive, ecosystem that better fits with the physical and chemical properties of the Sea. They believe that restoring the Sea should not be a priority. Others counter this sentiment by noting the severity of the projected effects of a shrinking sea on the environment and economy of the region. Understanding the science behind the ecosystem dynamics in the Salton Sea Basin is viewed as a priority by some who contend that long-term monitoring of the Salton Sea ecosystem is essential for deciding whether to restore the Sea or let it transition into a new ecosystem. The USGS and BOR collaborated with the California Department of Water Resources and Fish and Wildlife to create a Monitoring and Assessment Plan (MAP). This plan would implement a monitoring program that would establish a baseline understanding of the key factors in the Salton Sea ecosystem (e.g, salinity and area of exposed seabed, among others); fill in data gaps; and provide capacity for storing, managing, and analyzing data. The program is not intended to be a prescriptive plan for restoration, but rather aims to implement monitoring activities directed at species and habitats that could be affected by future restoration activities. The Salton Sea ecosystem has been steadily changing primarily due to less water entering the Sea. The notable changes are the decreasing area of the Salton Sea and increasing salinity of its waters. These changes have already caused stress on fish and wildlife species that reside in the ecosystem, and some avian species that use the ecosystem while migrating along the Pacific Flyway. The condition of the Salton Sea ecosystem is expected to change dramatically when water transfers authorized under QSA are implemented, thus reducing water inflows into the Sea. This is expected to increase the level of salinity in the Sea over a short period, thus making the Sea inhabitable for most existing fish and wildlife species. Severe effects on the ecosystem are expected as soon as 2018, according to some models. Several groups support restoring the Salton Sea ecosystem so that it can support fish and wildlife and stimulate economic development in the region. Specifically, proponents of restoring the Sea base their arguments on the value of the Salton Sea as one of the few remaining habitats in the region for migratory birds and other fish and wildlife. They note that with nearly 90% of California's original wetlands gone, the Sea is of regional or national importance to pelicans and cormorants, wading birds, waterfowl, shorebirds, gulls, and terns. Further, some note that a restored Sea could supports aquatic wildlife that include some threatened and endangered species and other species that might be able to support recreational or sport fishing practices. The value of a restored Sea, according to some, can also be measured in terms of its potential for recreation and economic development (e.g., tourism) as well as its function for agricultural drainage. Some opposed to restoring the Salton Sea base their arguments on the premise that the Salton Sea is destined to evaporate and eventually convert back to a desert ecosystem. Throughout geologic history, water bodies in the Salton Basin have eventually dried up, leading some scientists to hypothesize that evaporation and conversion to a salt brine would be the progression of the Salton Sea if no restoration activities are undertaken. Some critics also argue that salinity levels will increase in the Sea despite restoration attempts, especially if water inflows to the Sea are reduced by water transfers or other water diversions away from the sea. Further, without the ability to use fresh water from the Colorado River, many of the restoration plans and projects developed in the early 2000s may be infeasible. As noted earlier, some argue that the high cost of restoration and the scientific uncertainty of existing proposals might not warrant limited state and federal funds. They note that limited funds should be funneled to other restoration efforts in naturally occurring wetlands in the California San Francisco Bay Sacramento/San Joaquin Rivers Delta. Congress has addressed the restoration of the Salton Sea ecosystem through various laws that authorize, in part, the creation of restoration plans for the ecosystem and the testing of restoration methodologies through pilot projects. However, due to the pace of change in the Salton Sea and the anticipation of severe effects on the ecosystem due to water transfers, Congress may decide to address restoration by increasing the federal role in restoration efforts. This could be done by funding existing federal authorities that address, or could address, restoring the ecosystem; authorizing federal participation and appropriations for implementing existing restoration plans; and authorizing a new comprehensive plan to be created that might involve participation from federal and non-federal stakeholders, similar to other restoration initiatives around the country. Congress might also decide not to address restoration of the Salton Sea ecosystem, or, rather, maintain the status quo of federal participation. Federal Appropriations

Summary: The Salton Sea is located in southern California and is considered the largest inland water body in the state. The Salton Basin, where the Salton Sea is located, has supported many lakes and water bodies throughout its geological history. The Salton Sea was created when a canal gate broke in 1905 allowing fresh Colorado River water into the Basin. The Salton Sea is now sustained by agricultural runoff from farmlands in the Imperial and Coachella valleys. It provides permanent and temporary habitat for many species of plants and animals, including several endangered species. It also serves as an important recreational area for the region. The Salton Sea has been altered by increasing salinity and decreasing size caused by steadily decreasing water flows into the Sea. High salinity levels and shrinking area have been linked to habitat changes and stressed populations of plants and animals, economic losses in the region, and impaired air quality. Efforts to restore the Salton Sea ecosystem have been discussed and initiated through state and federal actions. Several studies by state and federal agencies have provided baseline data about the Sea, and some restoration plans have been proposed. The State of California, the Salton Sea Authority, and the federal government through the Bureau of Reclamation have devised plans for restoring the Sea. However, none of these plans are being fully implemented. Federal authorities that address restoration of the Salton Sea are generally based on creating and evaluating proposals for restoration, rather than implementing restoration activities in a comprehensive manner similar to other initiatives in the Everglades and Great Lakes. California is pursuing restoration options, but funding for implementing them is lacking. Whether or not to restore the Salton Sea remains controversial. Proponents of restoration contend that the Salton Sea ecosystem is valuable from an ecological standpoint because it is one of the few remaining large-scale wetland habitats in California for migratory birds and fish. Further, some argue that keeping the Salton Sea intact will stimulate economic development, recreation, and tourism in the region. They note that losing the Sea could cause economic and environmental decline, and could lead to air quality problems from exposed seabeds. Others contend that the Sea should not be restored. They argue that the Salton Sea is naturally declining, as it has throughout its geological history. Further, they note that countering this process will be costly and ultimately not worth the expense. They state that limited restoration funds should be used to restore other natural wetlands in California, such as the Sacramento-San Joaquin Bay Delta. The decline of the Salton Sea ecosystem is accelerating due to water transfers from agricultural lands to municipal water districts in San Diego under the terms of the Quantification Settlement Agreement, an agreement on how to share California's apportionment of Colorado River water. The water transfers have resulted in less water flowing into the Salton Sea and accelerated increases in salinity and shoreline recession. According to some scientists, salinity levels may reach lethal levels for most fish and wildlife as soon as 2018. These predictions, along with the steadily declining ecosystem might provoke Congress to consider a larger role in restoration for the federal government. Congress may decide to address restoration by increasing the federal role in restoration efforts. This could be done by funding existing federal authorities that address, or could address, restoring the ecosystem; authorizing federal participation and appropriations for implementing existing restoration plans; or authorizing a new comprehensive plan to be created that might involve participation from federal and non-federal stakeholders, similar to other restoration initiatives around the country. Congress might also decide not to address restoration of the Salton Sea ecosystem, or simply maintain the status quo of federal participation.