The Salton Sea is a shallow, landlocked, highly saline endorheic lake in Riverside and Imperial counties at the southern end of the U.S. state of California.

Water from spring floods broke through a canal head-gate, diverting a portion of the river flow into the Salton Basin for two years before repairs were completed.

California lawmakers pledged to fund air-quality management projects in conjunction with the signing of the 2003 agreement to send more water to coastal cities.

Local, state and federal bodies all had found minimal success dealing with the dust, dying wildlife, and other problems for which warnings had been issued decades before.

The Gulf of California would extend as far north as the city of Indio, some 150 miles (240 km) northwest of its current limits, were it not for the delta created by the Colorado River.

[8] In 1900, under Governor James Budd, the California Development Company began construction of irrigation canals to divert water from the Colorado River into the Salton Sink, a dry lake bed.

Engineer Charles Rockwood, faced with bankruptcy and "after mature deliberation", directed the construction of a breach in the bank of the Colorado River approximately 4 miles (6.4 km) south of the existing wooden headgates (the Chaffey Gate).

Originally, the waterfall was feared to recede upstream to the true main path of the Colorado, becoming up to 100 to 300 feet (30 to 90 m) high, when it would be practically impossible to stop the flow.

[29] The U.S. Department of the Interior prepared a draft Environmental Impact Report in compliance with the Reclamation Act and working in partnership with the Salton Sea Authority.

[37][41] Due to their concerns about the impact on the lake, the district only approved the water transfer agreement after Governor Gray Davis had signed the 2003 legislation known as the Salton Sea Restoration Act.

[44] A haze incorporating pesticide plumes, exhaust fumes, factory emissions, and the vaporized dust from the lake regularly hangs over the communities in the valley.

[52]: 4  The public health impacts of continuing not to meet federal air quality standards include the treatment of child and adult asthma, cardiac disease, lung cancer, and increased mortality rates.

[53] Residents in the Los Angeles Basin, some 150 miles (240 km) away, complained about the odor that drifted their way in 2012, after the biomass on the sea bottom was churned by a storm.

[31] A court decision also forced the Imperial Irrigation District to end a program that had allowed it to equally distribute and cap the amount of water its members receive.

[29] The state is mainly responsible, as California lawmakers pledged to fund air-quality management projects to mitigate impacts from the 2003 water transfer agreement.

[55] The SSMP proposed constructing 29,800 acres (12,100 ha) of habitat restoration and dust suppression projects on lakebed areas that have been, or will be, exposed at the Salton Sea by the year 2028.

[72] In October 2024, expanding the SCH project by 750 acres (300 ha) was announced with the allocation of $70 million in federal funding for improving drought infrastructure.

Their proposal involved the construction of over 20 miles (32 km) of pipes and tunneling that would have provided 1,000,000 acre-feet (1.2 km3) of water to Southern California coastal cities each year.

[76] Alternatively, a 2020 research report stated that the cost of "transferring water from agricultural users to the Salton Sea" would be lower and achievable using existing infrastructure.

[78] After a yearlong review, in 2022 a state-appointed panel of experts rejected the idea "based on its high cost, environmental damage, minimal benefits to Mexico" and other factors, recommending instead that fresh water be diverted to the sea.

[87] The body was initially a freshwater lake and was stocked with tilapia, gulf croaker, orangemouth corvina, and sargo, which sustained an important sport fishery and provided food for birds.

[94] The California Office of Environmental Health Hazard Assessment developed a safe eating advisory for fish caught in the Salton Sea based on levels of mercury or PCBs found in local species.

[96] It hosts "the most diverse and probably most significant populations of bird life in the continental United States, rivaled only by Big Bend, Texas;" over 400 species have been documented.

[98] The Salton Sea is notable as the only part of the United States to host a significant population of Yellow-footed gulls, a species otherwise endemic to the Gulf of California.

Due to changes in water apportionments agreed upon for the Colorado River under the Quantification Settlement Agreement of 2003, the surface area of the sea had been expected to decrease by 60% between 2013 and 2021.

Simulations also showed, in the Los Angeles area, shaking and thus damage would be more severe for a San Andreas earthquake that propagated along the fault from the south, rather than from the north.

[121] The California Energy Commission estimates the Salton Sea might produce 600k metric tons of lithium carbonate (Li2CO3) per year,[122] of a reserve of 3.4 million tonnes.

[125] The Salton Sea geothermal brine reservoir is located at depths of approximately 0.62 to 1.86 miles (1 to 3 km) below ground and contains fluids at temperatures ranging from 250 °C to 380 °C.

In late June 2020, a fire in Niland caused a great deal of damage, displacing 112 people; by that time, the estimated population had diminished to 500.

[136] From 1961 through 1965, the Sea hosted the Salton City 500, a marathon endurance race which attracted drivers as notable as Mickey Thompson and astronaut Gordon Cooper.