Salton Sea Restoration

Salton Sea Restoration

Salton Sea Restoration
July 28, 2021
The Salton Sea—a lake located in Southern California—is the largest inland water body in the
state. The sea has few natural inlets of water, has no natural outlets, and is largely sustained by
Pervaze A. Sheikh
agricultural runoff from farmlands in the Imperial and Coachella Valleys. In recent decades,
Specialist in Natural
agricultural runoff to the Salton Sea has diminished due to decreasing agricultural inflows ,
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evaporation, and reduced precipitation, causing the sea to shrink and increase in salinity. High

salinity levels, combined with greater concentrations of nutrients and toxins , have altered the
sea’s ecosystem and surrounding habitat, making it difficult for most fish and bird species to
Charles V. Stern
Specialist in Natural
survive. The Salton Sea’s diminishing size also has exposed lake bed (i.e., playa) around the
sea’s shoreline; this playa
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contains toxic substances that may circulate in the air and impair local

and regional air quality.

Over time, federal, state, and private entities have developed proposals to manage and restore
parts of the Salton Sea. These efforts have common objectives, including controlling salinity, maintaining some of the sea’s
habitat, and stabilizing sea water levels. The current and most prominent restoration initiative, the Salton Sea Management
Program (SSMP), was releas ed by the State of California in 2017. The SSMP’s first phase is being implemented from 2018
to 2028. The initiative includes activities to convey water to the Salton Sea, reduce salinity in the sea, and restore
approximately 30,000 acres of exposed playa. Phase 1 is estimated to cost $420 million. Some federal agencies, such as the
Bureau of Reclamation (part of the Department of the Interior), are collaborating with the State of California to implement
the SSMP.
The federal role in restoring the Salton Sea is limited to a handful of projects that address issues on lands in and around the
sea managed by federal agencies such as the U.S. Fish and Wildlife Service, the Bureau of Reclamation, the Bureau of Land
Management, and the Department of Defense. Unlike in areas such as Lake Tahoe, the Everglades, and the Chesapeake Bay,
Congress has not authorized a comprehensive program to restore the Salton Sea.
The scope and content of plans to restore the Salton Sea have generated debate, and legislation to provide additional federal
support for restoration has been introduced in the 117th Congress. Many stakeholders support restoring the Salton Sea
because of the sea’s ecological significance as a large wetland along the Pacific Flyway, its role in providing habitat for fish
and wildlife, and its economic importance to the region. Some also argue that restoration might mitigate the effects of
increasing playa exposure, which is linked to regional airborne pollution. Some observers contend the sea should not be
restored; they argue that the area’s geological history demonstrates a pattern of water bodies naturally shrinking,
disappearing, and reforming over time and assert that the Salton Sea is following a similar process. Congress may consider
issues related to restoring the Salton Sea, including the nature and extent of federal involvement in restoration; how (or if) the
federal government should collaborate with the State of California in restoration efforts under the SSMP; and what (if any)
federal responsibilities exist for mitigation of airborne toxins that occur due to exposed playa on federal lands.

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Contents
Introduction ................................................................................................................... 1
Background on the Salton Sea ........................................................................................... 2
Health of the Salton Sea Ecosystem.............................................................................. 4
Inflows to the Salton Sea ............................................................................................ 4
Salinity .................................................................................................................... 6
Fish and Wildlife ....................................................................................................... 7
Dust and Airborne Pollution ........................................................................................ 7
The Salton Sea and the Colorado River............................................................................... 8
Quantification Settlement Agreement............................................................................ 8
The Salton Sea and Colorado River Drought Contingency Plans ....................................... 9
Restoration and Mitigation Plans ..................................................................................... 10
Salton Sea Management Program ............................................................................... 11
Status of SSMP Implementation................................................................................. 13
Federal, State, and Local Roles in Restoration ................................................................... 14
Role of Congress........................................................................................................... 16
Issues for Congress ....................................................................................................... 17
Level of Federal Involvement in Restoration................................................................ 18
Collaboration with the State of California.................................................................... 18
Potential Effects of Airborne Pollution from the Salton Sea ............................................ 19
Conclusion................................................................................................................... 20

Figures
Figure 1. Map of Salton Sea and Vicinity in the State of California ......................................... 1
Figure 2. Salton Sea Elevation, 2003-2020 .......................................................................... 5
Figure 3. Historical and Projected Lake Bed (Playa) Exposure in the Salton Sea, 2002-
2020........................................................................................................................... 6
Figure 4. Proposed Areas to Implement Dust Suppression ................................................... 12
Figure 5. Salton Sea Management Program (SSMP) Project Delivery Timeline ...................... 14

Tables
Table 1. Salton Sea Restoration Plans ............................................................................... 10
Table 2. Role of Selected Federal, State, and Local Agencies in Salton Sea Restoration ........... 15

Appendixes
Appendix. Chronology of Events in the Salton Sea............................................................. 21

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Contacts
Author Information ....................................................................................................... 23

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Salton Sea Restoration

Introduction
The Salton Sea—an inland lake in Southern California near the U.S.-Mexican border—is the state
of California’s largest lake (Figure 1). The Salton Sea has higher salinity levels than the ocean
and provides habitat for many species of plants and animals, including several endangered
species. The Salton Sea’s ecosystem has deteriorated steadily over time, due largely to declining
water levels caused by evaporation, reduced precipitation, and decreased water inflows from
agricultural irrigation. Lower water levels have caused the sea to shrink, resulting in an increase
in its salinity and the exposure of lake bed (playa).1 High salinity levels, combined with toxic
substances in soils and runoff, have led to disease and widespread mortality of fish and birds, as
wel as to concerns about the effect of exposed playa on air quality.
Figure 1. Map of Salton Sea and Vicinity in the State of California

Source: California Legislative Analyst’s Office, “Restoring the Salton Sea,” at http://www.lao.ca.gov/2008/rsrc/
salton_sea/salton_sea_01-24-08.aspx.

1 D. A. Barnum et al., State of the Salton Sea: A Science and Monitoring Meeting of Scientists for the Salton Sea , U.S.
Geological Survey, Workshop Report, 2017, at https://pubs.usgs.gov/of/2017/1005/ofr20171005.pdf (hereinafter,
Barnum et al., State of the Salton Sea). Playa is exposed seabed in and around the Salton Sea.
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Over time, federal, state, and private entities have developed proposals to manage and restore
parts of the Salton Sea, with projected costs typical y in the bil ions of dollars. These efforts have
common objectives that include controlling salinity, maintaining some amount of wildlife habitat,
and stabilizing water levels. The current and most prominent effort to restore the Salton Sea, the
Salton Sea Management Program (SSMP), was released by the State of California’s Salton Sea
Task Force in 2017.2 Phase 1 of the program began in 2018 and is scheduled to be implemented
until 2028 at a cost of $420 mil ion. Absent the full implementation of a comprehensive Salton
Sea restoration plan, one study estimated the long-term social and economic costs to society of a
deteriorating sea could approach $29 bil ion.3
Federal involvement in the Salton Sea stems in part from the Bureau of Reclamation’s
development of the Colorado River, which facilitates transfers of Colorado River water to the
nearby Imperial and Coachel a Val eys for irrigation. Due to the federal government’s role in
developing the Colorado River Basin, as wel as the multiple federal landowners in the area,4
some stakeholders and members of Congress have proposed increasing the federal role in
restoration and mitigation efforts in the Salton Sea and have introduced legislation that would
facilitate this change. In the 117th Congress, H.R. 3877, the Salton Sea Projects Improvement Act,
would authorize $250 mil ion for Reclamation to implement mitigation and restoration projects in
and around the Salton Sea, in partnership with multiple state, local, and nonprofit entities.
Another bil , H.R. 491, would authorize a restoration program for the New River (a tributary
flowing into the Salton Sea).
This report provides background on the Salton Sea’s history, as wel as its current status, efforts
to restore parts of the sea and mitigate the effects of its decline, and the roles of the State of
California and the federal government in facilitating these efforts.
Background on the Salton Sea
The Salton Basin, an area below sea level where the Salton Sea is located, has supported many
lakes and water bodies throughout its geological history. The last of these water bodies was Lake
Cahuil a, a water body larger than the Salton Sea within the basin, which formed from
sedimentation in the Colorado River Delta. The lake existed during the Holocene epoch (the last
11,700 years), periodical y drying and refil ing.5 Beginning in 1901, irrigation canals were dug to
divert a portion of the Colorado River to irrigate agricultural fields in the Imperial Val ey, which

2 State of California Department of Water Resources, California Natural Resources Agency, and California Department
of Fish and Wildlife, Salton Sea Managem ent Program, 2017. Hereinafter, 2017 SSMP.
3 Michael J. Cohen, Hazard’s Toll: The Costs of Inaction at the Salton Sea, Pacific Institute, September 2014, p. vi, at
https://pacinst.org/publication/hazards-toll/. Hereinafter “ Hazard’s Toll.” Costs are estimated to come from public
health issues, loss in recreation and ecological values, loss in property values, and potentially losses in agricultural
productivity.
4 Federal lands in and around the Salton Sea include the Sonny Bono Salton Sea Wildlife Refuge, owned and operated
by the U.S. Fish and Wildlife Service (FW S); submerged lands owned by Reclamation and the U.S. Bureau of Land
Management (BLM); and various lands owned by the Department of Defense. For a more detailed accounting of land
ownership in and around the Salton Sea, see U.S. Bureau of Reclamation, “Gen eral Salton Sea and Vicinity Land
Ownership and Management Map DRAFT ,” April 16, 2015, at https://www.usbr.gov/lc/region/programs/
SaltonSeaOwnershipMap.pdf.
5 T he last major recorded flood of Colorado River water forming a lake in the basin was in 1891, forming a 100,000 -
acre lake. For more information, see Salton Sea Authority, “Timeline of Salton Sea History,” at https://saltonsea.com/
get-informed/history/ (hereinafter, Salton Sea Authority, “ Timeline”).
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is within the Salton Basin.6 In 1905, water entered the basin (which was mostly dry at the time)
through a broken canal. This inflow of Colorado River water into the area that is now the Salton
Sea lasted almost two years. The sea formed within a closed basin with no outlets (i.e., a terminal
lake), which is its present condition. Although the 1905 event has been widely noted in
descriptions of the sea’s origins, some scientists note that the evidence of similar bodies of water
and other floods prior to 1905 means Salton Sea’s formation was not an unnatural event.7
Subsequent development of the Colorado River by the federal government (including
construction of the Hoover Dam and the Al -American Canal) provided additional support for
transfers of Colorado River water to the Imperial Val ey. After being diverted to irrigate
agricultural lands in the Imperial Valley, this water drained into the Salton Sea and replenished
freshwater lost to evaporation. In the 1920s, President Coolidge issued public water and reserve
orders for the federal withdrawal of lands related to the Salton Sea, leading to an increasing
federal land ownership stake in the area.8 These lands were designated as a repository for
agricultural, subsurface, and surface water drainage. As a result, lands in and around the sea are
managed by a patchwork of federal, state, and local owners.
The Salton Sea was a popular destination for sport fishing and tourism as late as the 1950s, but a
combination of factors led to a gradual decline of these activities. Changes to the sea, including
the flooding of some 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 Salton Sea in the
1960s. Since then, water levels in the sea have fluctuated but have decreased overal , exposing
contaminated playa and leading to high salinity levels in the water.9 The Salton Sea also contains
high levels of nutrients, which can lead to large-scale algal blooms and toxic levels of
dichlorodiphenyldichloroethylene (DDE), a pesticide by-product.10 Some scientists assert that
these toxins, coupled with high salinity, are likely to further degrade water quality.11
The Salton Sea provides habitat, including open water, estuaries, salt marshes, and river corridors,
for various fish and wildlife species. The most ubiquitous fish species in the sea today is the
tilapia (Oreochromis mossambicus), which was introduced to the area in the 1960s to control
weeds in agricultural ponds. In addition, the Salton Sea is home to the endangered desert pupfish
(Cyprinodon macularius), the only native fish species in the sea. Few fish can survive in the sea’s
current hypersaline waters. According to scientists, deteriorating water quality adversely affects
invertebrate life in the sea, such as pileworms and barnacles, two key components of the sea’s
food web.12 The Salton Sea also is an important stop for thousands of birds on the Pacific Flyway,
many of which rely on its fish and invertebrates for sustenance during their migration.13

6 Robert H. Boyle, “Life—or Death—for the Salton Sea?,” Smithsonian (June 1996), pp. 87-93.
7 Jenny E. Ross, “Formation of California’s Salton Sea in 1905 -1907 Was Not ‘Accidental,’” 2020 Desert Symposium ,
2020, pp. 103-116.
8 Salton Sea Authority, “ T imeline.”
9 For example, from 1988 to 2007, water levels in the Salton Sea fluctuated between -227 feet to -228 feet below sea
level, but then declined to -237 feet below sea level in 2020. See USGS Annual Water Statistics for California at
https://waterdata.usgs.gov/ca/nwis/annual?referred_module=sw&search_site_no=10254005&format=
sites_selection_links.
10 DDE is a chemical compound formed by the breakdown of DDT (Dichlorodiphenyltrichloroethane), a pesticide
banned by the Environmental Protection Agency in 1972.
11 Barnum et al., State of the Salton Sea, p. 8.
12 Barnum et al., State of the Salton Sea, p. 3.
13 Barnum et al., State of the Salton Sea.
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Federal lands in and around the Salton Sea are managed by the Department of Defense (DOD)
and several agencies within the Department of the Interior (DOI). These lands include drainage
areas and refuges for fish and wildlife. For example, the Sonny Bono Salton Sea National
Wildlife Refuge was established in 1930 to provide wintering habitat for waterfowl and migratory
birds.14 It supports more than 400 species of resident and migratory birds, of which more than 50
are species of special status (including 3 listed under the Endangered Species Act).15 Reclamation
and BLM manage submerged lands and lands around the sea. Some of those lands border the
sea’s edges and increasingly are being exposed due to receding water levels. The playa in and
around the sea is covered with fine sediments, some of which contain toxic levels of substances,
such as selenium and arsenic, deposited both natural y and by agricultural runoff. When the
exposed lake beds dry, winds can blow up and transport dust, thereby impairing local and
regional air quality.
Interest in the Salton Sea’s ecological health has increased since 2003, when the Quantification
Settlement Agreement (QSA) was approved by several water districts in California, the State of
California, and DOI and signed into California law. The QSA required California to gradual y
reduce its consumption of Colorado River water from 5.2 mil ion to 4.4 mil ion acre-feet (MAF)
per year, in accordance with the Law of the River. This reduction was to be accomplished through
voluntary agriculture-to-urban water transfers and other water efficiency measures expected to
further reduce inflows into the Salton Sea. The water districts participating in the QSA agreed to
contribute funding and flows to mitigate the agreement’s effects on the Salton Sea. Most of these
measures were intended to be temporary actions on a path to long-term restoration and mitigation,
and many of them have since ended.
Health of the Salton Sea Ecosystem
The ecosystem properties of the Salton Sea are largely determined by its water level, chemical
concentrations (including salinity), and the balance between the rates of evaporation and water
inflow.
Inflows to the Salton Sea
Historical y, nearly 75% of the water flowing into the Salton Sea came from agricultural runoff
originating in California’s Imperial and Coachel a Val eys; the other 25% came from rain and
other surface inflows.16 Water levels in the sea began to decline due to increasing efficiencies
with irrigation water and decreasing inflows from Mexico; these levels dropped further after 2003
due to the QSA and evaporation, among other things. There has been an approximately 10-foot
reduction in water surface elevation since 2003 (Figure 2). Declining water levels have increased
playa exposure, which was nearing an estimated 25,000 acres at the end of 2019 (Figure 3).17

14 T his refuge was established in 1930 as the Salton Sea Wildlife Refuge and was renamed the Sonny Bono Salton Sea
National Wildlife Refuge in 1998.
15 U.S. Fish and Wildlife Service, Bird Life, Sonny Bono Salton Sea National Wildlife Refuge Complex, at
https://www.fws.gov/saltonsea/Bird%20List.html.
16 Michael Cohen, Jason Morrison, and Edward Glenn, Haven or Hazard: The Ecology and Future of the Salton Sea,
Pacific Institute for Studies in Development, Environment, and Security, February 1999, p. 10.
17 California Natural Resources Agency, 2020 Annual Report on the Salton Sea Management Program, February 2020,
p. 31, at http://saltonsea.ca.gov/wp-content/uploads/2020/02/2020-Annual-Report_2-21-20-v3.pdf. Hereinafter, 2020
Salton Sea Managem ent Program Annual Report.
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Figure 2. Salton Sea Elevation, 2003-2020

Source: U.S. Geological Survey, National Water Information System: Web Interface, at
https://waterdata.usgs.gov/ca/nwis/uv?site_no=10254005.
Notes: NGVD = National Geodetic Vertical Datum (see https://www.ngs.noaa.gov/datums/vertical/national-
geodetic-vertical-datum-1929.shtml).
Total average annual inflow to the Salton Sea between 1950 and 2015 was estimated at
approximately 1.3 MAF;18 average annual inflow prior to the 2003 QSA implementation was
estimated at 1.2-1.3 MAF,19 and annual inflows since QSA implementation have been as low as
1.0 MAF.20 From 2014 to 2019, inflows declined minimal y and averaged 1.07 MAF, despite the
end of mitigation flows under the QSA.21 Some project that the total annual average inflow to the
Salton Sea from 2016 to 2077 wil drop to a level of approximately 732,000 acre-feet per year if
there is no restoration.22 This drop is estimated to result in approximately 100,000 acres of
exposed playa and likely would increase salinity, raise concentrations of toxins, and exacerbate
effects on fish and wildlife.23

18 CH2M Hill, Salton Sea Hydrological Modeling and Results, T echnical Report Prepared for Imperial Irrigation
District, October 2018, p. 2-2, at https://www.iid.com/home/showdocument?id=17299. Hereinafter, CH2M Hill, Salton
Sea Hydrological Modeling.
19 IID, “Salton Sea,” at https://www.iid.com/water/salton-sea.
20 CH2M Hill, Salton Sea Hydrological Modeling, p. 2-2.
21 Anticipating a shortage of flows to the Salton Sea due to the Quantification Settlement Agreement (QSA), the State
Water Resources Control Board delayed the shortage for 15 years (2002-2017) by requiring mitigation flows to the
Salton Sea.
22 CH2M Hill, Salton Sea Hydrological Modeling, p. 5-3.
23 CH2M Hill, Salton Sea Hydrological Modeling, Section 6.0, pp. 6-1 to 6-10.
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Figure 3. Historical and Projected Lake Bed (Playa) Exposure in the Salton Sea,
2002-2020

Source: California Natural Resources Agency 2020 Annual Report on the Salton Sea Management Program,
February 2020.
Salinity
Lower inflows into the Salton Sea directly lead to increasing salinity levels. High salinity
combines with extreme eutrophication (excessive richness of nutrients), which causes fish kil s in
the sea by depleting oxygen levels in water (anoxia).24 In 1950, the sea reached salinity levels
similar to those of the Pacific Ocean. At that time, the California Department of Fish and Game
began transferring saltwater fish species to the sea. Salinity has increased in the sea ever since.
Salinity in the Salton Sea increased from approximately 45,600 mil igrams/liter (mg/l) in 2003 to
69,000 mg/l in 2019.25 These salinity levels are too high to support the sea’s former diversity of
fish, according to scientists.26 If there is no restoration and trends in salinity continue, some
studies suggest salinity in the Salton Sea could approximately double from 2018 levels by 2027
and triple by 2033.27

24Fish need oxygenated waters to survive; thus, depletion of oxygen is associated with large fish kills, which are
sometimes observed in the Salton Sea. See B. Marti-Cardona et al., “ Relating Fish Kills to Upwelling and Wind
Patterns in the Salton Sea,” in Developments in Hydrobiology: The Salton Sea Centennial Symposium Developments in
Hydrobiology, ed. Stuart Hurlbert, vol. 201 (2008), pp. 85 -95.
25 2020 Salton Sea Management Program Annual Report, p. 30. By comparison, average salinity of ocean water is
approximately 35,000 mg/l.
26 T estimony of Wade Crowfoot, California Secretary for Natural Resources, in U.S. Congress, House Committee on
Natural Resources, Subcommittee on Water, Oceans, and Wildlife, Efforts to Restore the Salton Sea, 116th Cong., 2nd
sess., September 24, 2020. Hereinafter, T estimony of Wade Crowfoot .
27 CH2M Hill, Salton Sea Hydrological Modeling, p. 6-7.
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Fish and Wildlife
An increase in salinity has led to the loss of most fisheries in the Salton Sea. The sea’s fish
species are declining due to hypersaline conditions; the endangered desert pupfish is in decline in
many parts of the sea, and scientists expect that increasing salinity eventual y wil cause the
species to disappear from the Salton Sea.28 The status of tilapia—the Salton Sea’s other major
fish species—is less clear, as these fish have adapted to high salinity conditions.29 However, some
scientists argue that tilapia might be reaching a tipping point due to hypersaline conditions and
that a massive die-off might be imminent.30 The numbers of fish-eating birds nesting in the Salton
Sea area have fal en to record lows, but the population of some other birds that feed on
invertebrates appears to have increased in recent years.31 Some stakeholders argue that the
ongoing loss of water into the sea wil continue to degrade the ecosystem, habitat, and species by
increasing salinity levels, producing higher concentrations of nutrients that lead to eutrophication
and anoxia, and elevating water temperatures.32
Dust and Airborne Pollution
Dust from exposed playa around the Salton Sea contains toxic substances that affect human
health. In October 2019, the Imperial County Board of Supervisors declared a local state of
emergency at the Salton Sea due to harmful dust and air pollution originating from the sea, which
was impairing air quality.33 The county also issued notices of violations of county regulations in
2020 to state agencies, federal agencies, and the Imperial Irrigation District (IID) for not
adequately controlling dust during the construction of the Red Hil Bay Restoration Project and
for not adequately implementing dust control activities on exposed playa around portions of the
Salton Sea.34
Some scientists support the premise that dust from exposed playa in the sea is the cause of
respiratory il ness in local communities. For example, a study directly connected declining water
levels in the Salton Sea to an increase in particulate matter and respiratory il nesses in
surrounding communities.35 At the same time, some scientists assert that it is difficult to assess
how increasing playa exposure is affecting air quality, because monitoring data vary due to wind
patterns and the location of monitoring sites relative to the sea. These scientists contend that air
pollution in the region also may be caused by stirring up the surrounding desert and by other

28 2020 Salton Sea Management Program Annual Report, p. 28.
29 2020 Salton Sea Management Program Annual Report, p. 28.
30 Salton Sea Authority, Frequently Asked Questions, 2020, at https://saltonseaauthority.org/about/faq/.
31 2020 Salton Sea Management Program Annual Report, pp. 28-29.
32 T estimony of Wade Crowfoot .
33 R. E. Kelley, Chairman of the Board of Supervisors, County of Imperial, Proclamation of Local Emergency for Air
Pollution at the Salton Sea, Imperial County Board of Supervisors, October 22, 2019, at https://imperial.granicus.com/
MetaViewer.php?view_id=2&event_id=1744&meta_id=251728.
34 For example, see K. Kirby, “ICAPCD Issues Notice of Violation to Protect Public Health,” The Desert Review,
October 14, 2020.
35 B. A. Jones and J. Fleck, “Shrinking Lakes, Air Pollution, and Human Health: Evidence from California’s Salton
Sea,” Science of the Total Environment, vol. 712 (April 10, 2020). T he study’s model indicated that each 1-foot drop in
lake elevation between 2008 and 2014 was associated with an increase in particulate matter that led to an increase in
respiratory mortality rates in surrounding communities of approximately 1 -15 people per year and health costs of $13.2
million-$147.3 million per year.
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natural sources; they recommend more studies.36 According to the California Air Resources
Board, migrating sand on the western shore of the Salton Sea is causing the highest particulate
matter readings and may increase total lake bed emissions unless the sand is stabilized.37
The Salton Sea and the Colorado River
The restoration of the Salton Sea is related to agreements that regulate the use and distribution of
water from the Colorado River, in particular those that affect the water diversions of the IID. One
agreement, the QSA, cal s for mandatory flows to the sea for a period of time. The other
agreement, the Drought Contingency Plan for the Lower Colorado River Basin, poses further
potential delivery curtailments in the Lower Basin and stimulated discussion among stakeholders
about Salton Sea restoration.
Quantification Settlement Agreement
Under the 1922 Colorado River Compact, seven states in the western United States agreed to
specified al otments of Colorado River water totaling 15 MAF per year, with California
apportioned 4.4 MAF out of this amount (the largest among the seven states). The states in the
Upper Colorado River Basin include Colorado, Utah, Wyoming, New Mexico, and part of
Arizona; the states in the Lower Basin include the rest of Arizona, California, and Nevada.38
Historical y, 75% (3.3 MAF per year) of California’s water was diverted to the Imperial and
Coachel a Val eys in Southern California (i.e., areas with irrigation drainage to the Salton Sea),
making these areas the largest users of Colorado River water in the basin. Through the early
1990s, California’s use of Colorado River water was on average 800,000 acre-feet per year in
excess of its al ocation of 4.4. MAF, primarily because other states in the compact were
withdrawing less than their shares. As other states increased their water consumption, the water
available for California was reduced to avoid major water-delivery shortfal s. In 1996, the
Secretary of the Interior required California to develop and enact a strategy to reduce its water
consumption to its al ocated levels. The result was the 2003 QSA, which provided for reductions
to California’s use of Colorado River water.
The QSA incorporated several changes that affected the Salton Sea. The agreement finalized a
1998 proposal revising water rights for the Colorado River Basin’s largest water rights holder—
IID—which directed the transfer, in gradual y increasing amounts, of Colorado River agricultural
diversions from IID to other users in Southern California.39 These reductions were agreed to on a
long-term basis (i.e., 45 years, with an optional 30-year renewal period) and were widely
acknowledged to result in reduced inflows to the Salton Sea.40 These inflow reductions were to be

36 E. Lindberg, “As Salton Sea Shrinks, Experts Fear Far-Reaching Health Consequences,” USC News, August 28,
2019, at https://news.usc.edu/159380/salton-sea-shrinking-asthma-respiratory-health-air-quality/.
37 California Air Resources Board, Salton Sea Windblown Dust Levels and Sources, 2019.
38 For background on Colorado River allocations, see CRS Report R45546, Management of the Colorado River: Water
Allocations, Drought, and the Federal Role, by Charles V. Stern and Pervaze A. Sheikh .
39 T ransfers from IID to the San Diego County Water Authority (SDCWA), the Coachella Valley Water District
(CVWD), and the Municipal Water District of Southern California are scheduled to peak at 303,000 acre -feet per year
beginning in 2026. For the full schedule, see Imperial Irrigation District, “Compromise IID/SDWCA & QSA Delivery
Schedule,” at https://www.iid.com/home/showpublisheddocument/4051/635648001335730000. Detailed accounting of
actual transfers is available in IID’s QSA annual reports at https://www.iid.com/water/library/qsa-water-transfer/qsa-
annual-reports.
40 At the time of the QSA’s signing, inflows to the Salton Sea from irrigation drainage were approximately 1.4 million
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mitigated by water transfers from IID to the sea over the next 15 years (i.e., through 2017), with
the intent to provide time to study and implement long-term restoration actions.41 QSA signees
acknowledged that after that time, additional mitigation actions would be required to prevent the
precipitous decline in the level and water quality of the Salton Sea.
As part of the QSA, the State of California agreed to assume responsibility for Salton Sea
mitigation costs in excess of $133 mil ion (2003 dollars).42 State legislation implementing the
QSA directed multiple mitigation measures intended to restore the sea, from water transfers to
restoration actions. QSA implementing legislation also required the state to identify a Salton Sea
restoration plan—and a funding plan to implement the restoration plan—and specified that the
California Department of Natural Resources should lead these efforts.43 (For more information on
restoration efforts, see “Restoration and Mitigation Plans,” below.)
The Salton Sea and Colorado River Drought Contingency Plans
Ongoing drought conditions in the western United States and the potential for water supply
shortages prompted Colorado River Basin states to engage in negotiations with Reclamation,
which manages some Colorado River waters and informs the Secretary of the Interior in the
Secretary’s capacity as lower basin water master. These negotiations focused on additional future
reductions (i.e., delivery cutbacks beyond prior agreements) and other basin-wide actions related
to Colorado River water deliveries. After several years of negotiations, on March 19, 2019,
Reclamation and the Colorado River Basin states finalized drought contingency plans (DCPs) for
the Upper and Lower Colorado River Basins. The DCPs included commitments to curtail water
deliveries under some scenarios, including—for the first time—cutbacks to California’s deliveries
if Lake Mead (the reservoir behind Hoover Dam) water levels dropped below a certain elevation.
These plans, which required congressional authorization to be implemented, were enacted on
April 16, 2019, in the Colorado River Drought Contingency Plan Authorization Act (P.L. 116-
114).
To be fully implemented, the DCPs also required additional agreements by state and local entities
that would make it possible to realize the plans’ state-level commitments. Whereas most states
and users approved the DCPs, IID made its approval contingent on the State of California and the
federal government committing to funding for the 10-year Phase 1 Plan of the SSMP at a 1:1
federal-to-state funding ratio. IID required that this commitment be in addition to mitigating al
future conditions resulting from the DCPs. At the time, IID’s main financial request of the federal
government was for the U.S. Department of Agriculture (USDA) to al ocate $200 mil ion in
funding from the 2018 farm bil (P.L. 115-334) for Salton Sea restoration. USDA did not commit
2018 farm bil funds and, as a result, IID did not support the final approved legislation.44

acre-feet per year. Agricultural drainage flows typically make up 90% of inflows to the Salton Sea.
41 According to IID, these requirements resulted in transfers of 776,757 acre-feet for Salton Sea Mitigation
Conservation from 2003 to 2019. See Imperial Irrigat ion District, Water & QSA Im plem entation Report, 2019 , at
https://www.iid.com/water/library/qsa-water-transfer/qsa-annual-reports.
42 T his is the amount the QSA requires the three local water agencies (IID, CVWD, and SDCWA) to pay for
restoration.
43 California Fish and Game Code, §§2931, 2942.
44 R. E. Kelley, Chairman of the Board of Supervisors, County of Imperial, Proclamation of Local Emergency for Air
Pollution at the Salton Sea, Imperial County Board of Supervisors, October 22, 2019, at https://imperial.granicus.com/
MetaViewer.php?view_id=2&event_id=1744&meta_id=251728.
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Restoration and Mitigation Plans
Since the early 1960s, various federal, state, and private entities have developed comprehensive
proposals to restore the Salton Sea and mitigate issues associated with its declining lake levels.
These plans have common objectives to control salinity, maintain and restore habitat, and
stabilize water levels, although the methods for achieving these goals differ. Table 1 provides a
list of five recent plans for restoring the Salton Sea. Some of these plans incorporate elements of
prior plans or express consistency with other plans that were under development. For example,
the 2007 Reclamation feasibility study incorporated many elements of the prior state and
nongovernmental plans, and the 2015 IID plan noted its consistency with the state’s phased
approach to restoration, which was in early planning stages.
Table 1. Salton Sea Restoration Plans
(restoration plans since 2000)
Plan Name (Year)
Lead Entity
Description
Estimated Cost
Salton Sea Authority Plan
Salton Sea Authority
Restoration plan that
Not available
for Multi-Purpose Project
included the construction
(2006)a
of a causeway across the
center of the Salton Sea.
Salton Sea Ecosystem
State of California
Comprehensive
$8.9 bil ion (2007 dol ars)
Restoration Program
restoration plan issued in
Programmatic
response to requirements
Environmental Impact
under 2003 Quantification
Report (2007)b
Settlement Agreement.
Comprehensive Report on
Bureau of Reclamation
Federal study laying out
$3.5 bil ion to $14 bil ion
Restoration of the Salton
five alternative
(2006 dol ars)
Sea (2007)c
restoration plans and a
no-action alternative.
Salton Sea Restoration and
Imperial Irrigation District
Initiative with design
$3.1 bil ion (2016 dol ars)
Renewable Energy Initiative
concepts for restoration,
(2015)d
air quality mitigation,
geothermal development,
and other renewable
energy technologies.
Salton Sea Management
State of California
Two-phase plan for
Phase 1 Plan: $420 mil ion
Program (2017)e
restoring the Salton Sea
(2017 dol ars)
by conveying water to the
Phase 2 Plan: TBA
lake, reducing salinity, and
covering/restoring
approximately 30,000
acres of exposed lake
bed.
Source: CRS, based on individual restoration plans (see below).
Notes:
a. TetraTech, Salton Sea Funding and Feasibility Action Plan, Salton Sea Authority, May 2016, p. 21, at
https://saltonseaauthority.org/wp-content/uploads/2019/11/SSA-Benchmark-7-for-FFAP.pdf.
b. California Department of Water Resources and California Department of Fish and Game, Salton Sea
Ecosystem Restoration Program Final Programmatic Environmental Impact Report, 2007.
c. U.S. Bureau of Reclamation, Restoration of the Salton Sea, December 2007, at https://www.usbr.gov/lc/region/
saltnsea/finalreport/index.html.
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d. Imperial Irrigation District, Salton Sea Restoration and Renewable Energy Initiative Framework Document, July
2015, at https://saltonseanow.com/wp-content/uploads/2015/07/Draft-SSRREI-Framework-Document-July-
22-2015.pdf.
e. California Department of Water Resources, California Natural Resources Agency, an d California
Department of Fish and Wildlife, Salton Sea Management Program, Phase 1: 10-Year Plan, March 2017.
As noted, the State of California agreed to assume responsibility for restoring the Salton Sea as
part of the QSA. In November 2014, IID submitted a petition to the California State Water
Resources Control Board to exercise its authority over the QSA, as adopted in Revised Water
Rights Order (WRO) 2002-0013.45 Among other things, IID argued that WRO 2002-13 approved
QSA transfers conditioned upon California’s fulfil ment of its statutory commitment to restore the
Salton Sea. Based on the state’s lack of restoration progress to date, IID asked the state water
board to enter an order to ensure its success. On November 7, 2017, the state water board
responded with a revision to its 2002-0013 order in the form of Order WR 2017-0134, which
required annual commitments by the state and a framework for Salton Sea restoration and
mitigation efforts.46 The order acknowledged the SSMP, which had been released since IID filed
its petition (see “Salton Sea Management Program” for additional discussion). The order required
the State of California, through the California Natural Resources Agency (CNRA), to begin
restoring the Salton Sea so that approximately 30,000 acres of exposed playa would be restored
through habitat and dust suppression projects by December 31, 2028. The order also cal ed on the
CNRA to identify a long-term plan for restoring the sea for an initial 10 years and to develop
subsequent 10-year plans to guide projects after the initial 10-year plan was completed.
Salton Sea Management Program
The State of California’s current plan for restoring the Salton Sea dates to 2015, when then-
Governor Jerry Brown formed the state Salton Sea Task Force and directed it to take actions
related to the sea. The task force was to create the SSMP, develop a process to accelerate project
implementation and delivery, and meet short- and medium-term goals for dust suppression and
habitat projects (Figure 4).47 The SSMP was created in 2017 and is a comprehensive, multiphase
restoration program for the Salton Sea. In 2018, the California Natural Resources Agency, the
Department of Water Resources, and the Department of Fish and Wildlife released a 10-year
Phase 1 plan (i.e., from 2018 through 2028) to begin implementing the SSMP.48

45 State of California, State Water Resources Control Board, “Petition of Imperial Irrigation District for Modification of
Revised Water Rights Order 2002-0013, Im perial Irrigation District’s (IID) and San Diego County Water Authority’s
(SDCWA) Am ended Joint Petition for Approval of a Long -Term Transfer of Conserved Water from IID to SDCWA and
to Change the Point of Diversion, Place of Use, and Purpose of Use Under Perm it 7643 on Application 7482 of
Im perial Irrigation District,” November 18, 2014.
46 State of California, State Water Resources Control Board, Order WR 2017-1034, In the Matter of Imperial Irrigation
District Regarding State Water Board Revised Order WRO 2002 -0013.
47 T he short-term goal was 9,000-12,000 acres of dust suppression and habitat projects, and the medium-term goal was
18,000 to 25,000 acres of projects.
48 California Natural Resources Agency, California Department of Water Resources, and California Departmen t of Fish
and Wildlife, Salton Sea Managem ent Program : Phase 1 -10 Year Plan, August 2018.
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Figure 4. Proposed Areas to Implement Dust Suppression

Source: California Natural Resources Agency, 2020 Annual Report on the Salton Sea Management Program,
February 2020, p. 31, at http://saltonsea.ca.gov/wp-content/uploads/2020/02/2020-Annual-Report_2-21-20-v3.pdf.
Notes: Phase A project areas began construction in 2020. Phase B project areas were being planned in 2020 and
are to be implemented in 2021.
Phase 1 of the SSMP includes projects and activities that aim to restore habitat for fish and
wildlife in the Salton Sea and suppress dust. The projects are a sequence of habitat and dust
control projects around the sea that are consistent with the Salton Sea Species Conservation
Habitat (SCH) Project and the Salton Sea Ecosystem Restoration Program Programmatic
Environmental Impact Report. Overal , Phase 1 projects aim to address approximately 30,000
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acres around the Salton Sea. Approximately 15,000 acres are to be used for fish and wildlife
habitat restoration, and approximately 15,000 acres are to be used for dust suppression projects.49
DOI entered into several memoranda of understanding (MOUs) with California as DOI developed
and undertook work on the SSMP, most recently in the form of an MOU executed in August
2016.50 Among other things, DOI, through Reclamation, agreed to designate officials to serve on
the Salton Sea Working Group; coordinate federal spending with state spending; recognize the
state’s SSMP restoration and mitigation project goals; and agree to pursue federal appropriations,
budgets, and funding opportunities to support certain SSMP activities.51 In addition to
Reclamation, other federal engagement on the SSMP includes FWS efforts to implement the Red
Hil Bay Restoration Project; an agreement with the U.S. Army Corps of Engineers (USACE) to
facilitate funding and permitting under the National Environmental Policy Act (NEPA) to
implement restoration authorities in the Salton Sea; and efforts by USDA’s Natural Resources
Conservation Service (NRCS) to support the SSMP’s objectives through a Regional Conservation
Partnership Project.
As of 2018, the total estimated cost for Phase 1 of the SSMP was $420.0 mil ion (2017 dollars). 52
Available funding anticipated for the plan includes funding from California state water bonds
passed in 2014 (Proposition 1) and 2018 (Proposition 68), plus other appropriated funding
sources. As of 2020, state appropriated funds totaled $345.3 mil ion, with the majority of these
funds yet to be spent.53
Status of SSMP Implementation
In 2020, the state completed the first SSMP project, the 112-acre Bruchard Road Dust
Suppression Project. The Species Conservation Habitat Project—a major component of the
SSMP—was expected to begin in 2020 and to be completed by the end of 2023.54 The project’s
aim is to construct ponds, within approximately 4,110 acres, to restore fish-eating bird habitat lost
due to increasing salinity and exposed playa. In July 2020, the state developed a Dust
Suppression Action Plan to prioritize 8,200 acres of dust suppression projects at various emissive
lake bed locations.55 California also is continuing the programmatic environmental planning
process that is to al ow for NEPA compliance and federal permitting of the 30,000 acres in the
Phase I plan. In addition, the state is working on the long-term (i.e., post-2028) plan for
restoration. Figure 5 shows the status of the SSMP’s various projects and processes.

49 California Natural Resources Agency, Updated Draft Salton Sea Management Program: Phase 1 10 -Year Plan
Project Description, March 2021, pp. 1-1, at https://saltonsea.ca.gov/wp-content/uploads/2021/03/Updated-Draft-
Salton-Sea-Management -Program-Phase-I-10-Year-Plan-Project-Description-March-2021.pdf.
50 “Memorandum of Understanding by and Between the United States Department of the Interior and the State of
California Natural Resources Agency Regarding the Cooperation of Activities to Manage the Salt on Sea,” August 31,
2016, at https://www.doi.gov/sites/doi.gov/files/uploads/ca-doi_2106_ss_mou_signed_1.pdf. Hereinafter, 2016 MOU.
T his memorandum was amended in January 2017.
51 2016 MOU, p. 5.
52 State of California Department of Water Resources, California Natural Resources Agency, and California
Department of Fish and Wildlife, Salton Sea Managem ent Program , August 2018.
53 2020 Salton Sea Management Program Annual Report, p. 14.
54 Salton Sea Management Program, Project Delivery, 2021, at https://saltonsea.ca.gov/projects/.
55 2020 Salton Sea Management Program Annual Report, p. 6. Gavin Newsom, Governor of California, California
State Budget 2020-2021: Sum mary, State of California, June 26, 2020, p. 93, at http://www.ebudget.ca.gov/budget/
2020-21EN/#/BudgetSummary.
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The State of California included $47 mil ion in its FY2020 budget to address issues in and around
the Salton Sea. A portion of those funds (approximately $28 mil ion) is to be used for restoration
activities in the New River, which feeds into the sea. Another portion (approximately $19 mil ion)
is to be for the North Lake Pilot Project, which aims to construct a deepwater recreational area in
the northern portion of the Salton Sea.56
Figure 5. Salton Sea Management Program (SSMP) Project Delivery Timeline

Source: California Natural Resources Agency, 2020 Annual Report on the Salton Sea Management Program,
February 2020.
Federal, State, and Local Roles in Restoration
The State of California is leading restoration activities in the Salton Sea, along with the Salton
Sea Authority, IID, and the Torres-Martinez Band of Desert Cahuil a Indians. Federal actions
directed toward restoring the Salton Sea are not following any comprehensive plan; however,
USACE is the designated federal partner for the SSMP. Restoration efforts by federal agencies
are largely in the form of pilot projects; monitoring; and individual agency plans, proposals, or
authorities. Table 2 presents a summary of federal, state, and local entities and their activities to
restore the Salton Sea.

56 Gavin Newsom, Governor of California, California State Budget 2020-2021: Summary, State of California, June 26,
2020, p. 93, at http://www.ebudget.ca.gov/budget/2020-21EN/#/BudgetSummary.
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Table 2. Role of Selected Federal, State, and Local Agencies
in Salton Sea Restoration
Entity
Role in Restoring the Salton Sea
Federal Agencies

Bureau of Reclamation
Implements the Salton Sea Research Project and other restoration activities. In
addition to general Reclamation authorities under the Reclamation Act of 1902,
several laws form the basis for Reclamation’s Salton Sea Research Project. P.L. 102-
575 directed the Secretary of the Interior (via Reclamation) to conduct research on
projects to control salinity levels, provide habitat for endangered species, enhance
fisheries, and protect recreational values in the Salton Sea.
Authorized to conduct feasibility studies on restoration options for the Salton Sea
(transmitted in January 2000) and to authorize river reclamation and restoration
activities on the New and Alamo Rivers (tributaries that flow into the sea). P.L. 108-
361 directed the Secretary of the Interior, in coordination with the State of
California, to complete a feasibility study on a preferred alternative for Salton Sea
restoration (transmitted in 2007).
Partnered with the U. S. Geological Survey to implement the Salton Sea Ecosystem
Monitoring Project to evaluate the feasibility of restoring shal ow water saline
habitat ponds prior to implementing larger projects.
U.S. Fish and Wildlife
Administers the Salton Sea National Wildlife Refuge in the southern edge of the
Service
Sea. Implementing the Red Hil Bay Restoration Project adjacent to the Salton Sea
Wildlife Refuge under the authority of the National Wildlife Refuge System
Administration Act (16 U.S.C. §668dd); the project aims to restore wetland habitat
for migratory birds and waterfowl and to suppress dust.
U.S. Geological Survey
Conducts scientific studies in and around the Salton Sea related to restoration and
energy development. Some of these activities are under the Ecosystems Research
Program and the National Water Quality Assessment Program.
U.S. Army Corps of
Authorized to conduct ecosystem restoration in the Salton Sea through §3032 of
Engineers
P.L. 110-114, as amended. This provision authorizes a program to implement
project-specific restoration plans and projects consistent with studies to increase
the success of ful -scale restoration projects in the sea.
U.S. Department of
Partnered with the Salton Sea Authority in a Regional Conservation Partnership to
Agriculture, Natural
provide technical and financial assistance to farmers in the Imperial Irrigation
Resources Conservation
District (IID), which is within the Salton Basin. The project aims to improve water
Service
quality, reduce poor air quality, improve soils and drought resistance, and conserve
species habitat of the sea.
State Agencies

California Natural
Is the lead state agency overseeing and guiding Salton Sea activities. Coordinates
Resources Agency
and negotiates with other local, state, and federal agencies.
California Department of
Implements most of the state’s restoration projects at the Salton Sea, including
Water Resources
engineering and design, contracting, construction, and operations and maintenance.
State Water Resources
Responsible for protecting water quality, water flows for aquatic life, and water
Control Board
rights, including permits for Quantification Settlement Agreement (QSA) water
transfers and mitigation water, and for requiring the state to construct specified
projects at the Salton Sea.
California Department of
Designs Salton Sea habitat projects and conducts monitoring. Issues regulatory
Fish and Game
permits for restoration projects and administers the Salton Sea Restoration Fund.
Tribal

Torres‑Martinez Band of
Largest private landowner of property around the Salton Sea. Partners with other
Desert Cahuil a Indians
agencies on restoration projects, including pilot wetland project on tribal land at
north end of the sea.
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Entity
Role in Restoring the Salton Sea
Local/Regional Entities

Quantitative Settlement
Includes the IID, Coachel a Val ey Water District, San Diego County Water
Agreement Joint Powers
Authority, and state Department of Fish and Wildlife. Administers funding for
Authority (QSA-JPA)
implementing mitigation activities required by QSA permits.
Coachel a Val ey Water
Party to the QSA that helps to fund mitigation projects required by QSA permits
District (CVWD)
and serves as legal counsel for the QSA-JPA. Responsible for water deliveries for
irrigation and domestic uses in the Coachel a Val ey near the Salton Sea.
San Diego County Water
As a party to the QSA, funds a portion of the mitigation projects required by QSA
Authority (SDWA)
permits and handles administration and finance for the QSA-JPA.
Imperial Irrigation District
As a party to the QSA, transfers up to 300,000 acre‑feet per year of its water to
CVWD and SDWA. Helps to fund the mitigation projects required by QSA permits
and implements those projects for the QSA-JPA. One of the largest landowners in
the region. Delivers Colorado River water to irrigate farmland in the Imperial Val ey
near the Salton Sea.
Federal-State

Collaboration
Salton Sea Authority
Joint powers authority authorized to restore the Salton Sea in consultation and
cooperation with the federal government and the State of California.
Source: Adapted from Rachel El ers, The Salton Sea: A Status Update, California Legislative Analyst’s Office,
August 29, 2018, at https://lao.ca.gov/Publications/Report/3879.
Notes: A joint powers authority in California is an entity that al ows two or more public agencies to jointly
exercise common powers. These entities are formed by the California state government and are not considered
federal entities overseen by Congress.
Role of Congress
California has largely spearheaded restoration of the Salton Sea. Congress has enacted multiple
bil s to guide federal activities and to provide authorities for federal involvement in the sea’s
restoration; however, there is no comprehensive law or authority for federal agencies to
holistical y address the Salton Sea ecosystem through either a federal initiative or a joint state-
federal initiative.
Since 1992, the following bil s have been enacted to address Salton Sea restoration:
 The Reclamation Projects Authorization and Adjustment Act (Title XI, §1101 of
P.L. 102-575) established that restoration of the Salton Sea was of national
interest and 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 sea.
 The Salton Sea Recovery Act of 1998 (P.L. 105-372) expanded restoration
activities in the sea. The act authorized the Secretary of the Interior to conduct
feasibility studies of various options for restoring the Salton Sea and studies of
wildlife and species’ responses to the sea’s hydrology and toxicology. The act
also authorized river reclamation activities for the New and Alamo Rivers
(tributaries that flow into the Salton Sea) and provided authority to aid in several
restoration projects administered through the state-funded Salton Sea Authority.
 Section 3032 of the Water Resources Development Act of 2007 (P.L. 110-114), as
amended by Section 1181 of the Water Infrastructure Improvements for the
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Nation Act (P.L. 114-322) authorized a program for project-specific Salton Sea
restoration plans and projects consistent with previously published studies to
increase the success of full-scale restoration projects.57
 The resolution on Salton Sea and Tributaries, Riverside, Imperial, and San Diego
Counties, California, by the Senate Environment and Public Works Committee
on April 28, 2016 (Senate Hearing 114-323) authorized USACE to review the
Chief of Engineers’ reports contained in the preliminary examination report on
flood control for al streams in San Diego and Imperial Counties, CA, flowing
into the Salton Sea, dated July 15, 1943, and other pertinent reports to determine
the advisability of federal participation in providing improvements for flood risk
management, ecosystem restoration, and other water- and land-related resources
for the Salton Sea and its vicinity. The examination was to focus on restoration
and protection of the environment and on improvements to public health and
safety for the Salton Sea and tributaries in Riverside, Imperial, and San Diego
Counties, CA.
Recent appropriations legislation has provided funding for restoration activities, in particular to
Reclamation.58 From FY2016 to FY2021, Congress appropriated $13.1 mil ion to Reclamation
specifical y for Salton Sea restoration. (Most of this funding was in addition to the President’s
annual budget requests.59) Congress has not appropriated funds to USACE to address the Salton
Sea, although USACE has the authority to conduct restoration in the Salton Sea if funding were
to be provided.60
In the last five fiscal years, Congress has appropriated funds to FWS and the NRCS for
restoration activities in the Salton Sea. FWS is leading the Red Hil Bay Restoration Project,
which aims to restore 530 acres of wetland habitat for sensitive species. The project is a joint
effort by FWS and IID. Federal assistance for the Red Hil Bay Restoration Project is from
funding al ocated to the Sonny Bono Salton Sea Wildlife Refuge. According to FWS, the project
has received approximately $1.0 mil ion and is not yet finished.61 NRCS partnered with the
Salton Sea Authority in a Regional Conservation Partnership to provide technical and financial
assistance to farmers in the IID, which is within the Salton Basin. The project aimed to improve
water quality, reduce poor air quality, improve soils and drought resistance, and conserve species
habitat of the sea.62 USDA provided $7.5 mil ion and leveraged $50.6 mil ion from partner-
provided funding for the project, which ran from 2016 to 2020.
Issues for Congress
Congress might consider several issues related to Salton Sea restoration. For example, Congress
may be interested in the overal level and type of federal involvement in this restoration, the

57 U.S. Army Corps of Engineers (USACE), “ Salton Sea Restoration Pilot Projects, CA,” February 2020, at
https://www.spl.usace.army.mil/Portals/17/docs/congressional/Fact_Sheets/PPMD/
SaltonSeaRestorationProjectsFactSheet.pdf?ver=2020-04-27-195654-350.
58 Reclamation typically is funded in annual Energy and Water Development and Related Agencies appropriations bills.
59 Work plans describing the distribution of “additional funds” are available at https://www.usbr.gov/budget/.
60 Personal communication with USACE, August 20, 2020.
61 Personal communication with the U.S. Fish and Wildlife Service, August 28, 2020.
62 Natural Resources Conservation Service, Salton Sea Water Quality, Air Quality and Agricultural Wetlands, August
24, 2020, at https://www.nrcs.usda.gov/wps/portal/nrcs/detail/ca/programs/farmbill/rcpp/?cid=nrcseprd1304025.
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extent of collaboration with the State of California, and any potential federal efforts to mitigate
the health effects of airborne toxins due to exposed playa.
Level of Federal Involvement in Restoration
Recent federal involvement in restoring the Salton Sea is largely limited to selected efforts to
complement the SSMP, including restoration activities on federal lands such as the Sonny Bono
Salton Sea National Wildlife Refuge. Some policymakers contend that federal resources for
restoring the Salton Sea should increase to restore the sea.63 Others support greater federal
involvement in restoration because they believe the federal government has a responsibility to
help restore the ecosystem for fish and wildlife and to reduce the threat of airborne pollutants.64 In
contrast, some policymakers contend the Salton Sea is artificially maintained through runoff and,
therefore, the federal government should use its limited resources for other priorities, such as
fighting forest fires.65 These policymakers and other stakeholders also contend that the State of
California should bear the primary responsibility for restoring the Salton Sea, per its commitment
under the QSA.66
Congress has appropriated steady funding for restoring the Salton Sea in recent years. Some in
Congress proposed increased federal involvement in restoration of the sea in report language in
the form of newly authorized restoration projects and studies; however, most of these requests
have not been enacted.67 In the 117th Congress, H.R. 3877, the Salton Sea Projects Improvement
Act, would authorize $250 mil ion for Reclamation to implement projects in and around the
Salton Sea to suppress dust, improve water quality, and restore fish and wildlife habitat. Under
the legislation, Reclamation could carry out authorized projects as grants, cooperative
agreements, and contracts in cooperation with a number of state and local government entities
and nonprofits. Other legislation, such as H.R. 491, looks to improve conditions in tributaries to
the sea and thus could have an impact on the sea’s long-term ecological health.
Other proposals also might require an increased federal role. For example, an IID-proposed plan
to use a portion of revenues from geothermal energy and mineral recovery projects to fund Salton
Sea restoration and to reduce dust emissions from the sea likely would involve increased federal
support.68 The plan would involve a collaboration between the IID, the federal government, and
other stakeholders. It is unclear what new authorities, if any, this plan would require.
Collaboration with the State of California
Some collaboration has occurred between the federal government and the state to restore the
Salton Sea. In 2016, DOI signed an MOU with the State of California and other nonfederal
entities to participate in efforts to restore 25,000 acres of dry lake bed and to implement the

63 Congressional Hearing, Restore Salton Sea, 2020, comments by Rep. Raul Ruiz.
64 T estimony of Wade Crowfoot .
65 Statement of Hon. T om McClintock.
66 Statement of Hon. T om McClintock.
67 In its FY2021 Energy and Water Development Appropriations report ( H.Rept. 116-449, accompanying H.R. 7613),
the House Appropriations Committee encouraged USACE to be an active participant in restoration, includi ng efforts to
implement the California Natural Resources Agency’s SSMP.
68 IID, Unlocking the Salton Sea’s Renewable Energy Potential, May 12, 2016, at https://www.iid.com/home/
showdocument?id=8599 and Congressional Hearing, Restore Salton Sea, 2020.
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SSMP.69 The MOU also included commitments to coordinate on implementing projects that aim
to improve air and water quality, fish and wildlife habitat, water security, existing obligations
with American Indian communities, and resource management decisions. This MOU was
preceded by an MOU between DOI and the Salton Sea Authority in 2014 for collaboration on
scientific and technical information related to the sea.70
Some argue that the federal government should increase collaboration with the State of California
to implement the SSMP. Among other things, this collaboration might involve additional
commitments related to the SSMP and a clearer indication of what direction the federal
government plans to take in regard to future implementation.71
Congress might consider options in other restoration initiatives to increase collaboration between
the federal government and the state. One option may be to authorize an intergovernmental task
force to streamline coordinated restoration efforts among federal and state agencies and to
organize federal efforts to restore the Salton Sea; similar task forces and advisory bodies exist for
restoration initiatives in the Chesapeake Bay, Great Lakes, Everglades, and Lake Tahoe. Some
policymakers might oppose this option because of lower levels of federal investment in
restoration relative to state levels, arguing there might not be enough activities to justify a task
force or a federal-state group. Other stakeholders might support directing federal agencies to
collaborate with the state in restoration activities. For example, in report language to accompany
proposed FY2021 appropriations legislation, the House Committee on Appropriations directs
USACE and Reclamation to partner with federal, state, and local agencies to support Salton Sea
restoration and implement the SSMP.72 This report language would also direct the USACE to
focus on specific projects that take a multi-agency approach to improving habitat and water
quality and increasing public health benefits.73
Potential Effects of Airborne Pollution from the Salton Sea
Some stakeholders are concerned about the effects on human health of airborne pollution from
exposed playa. These stakeholders might look to Congress to address the issue. Reclamation
noted that approximately 8.75 square miles of submerged Reclamation lands under the Salton Sea
could be exposed to the air in the next 10 years as the sea recedes, which might lead to significant
air quality mitigation costs under the Clean Air Act (42 U.S.C. 7401 et seq.).74 In its FY2021
budget justification, Reclamation compared the sort of mitigation efforts that may be required in
the Salton Sea to existing efforts under the Great Basin Unified Air Pollution Control District’s

69 2016 MOU.
70 Department of the Interior (DOI), “Department of the Interior and Salton Sea Authority Sign Joint Memorandum of
Understanding,” press release, March 4, 2014, at https://www.doi.gov/news/pressreleases/department-of-the-interior-
and-salton-sea-authority-sign-joint-memorandum-of-understanding.
71 For example, see testimony of Joaquin Esquivel, Chair, California State Water Resources Control Board, in U.S.
Congress, House Committee on Natural Resources, Subcommittee on Water, Oceans, and Wildlife, Efforts to Restore
the Salton Sea, 116th Cong., 2nd sess., September 24, 2020.
72 House Appropriations Committee, Report on FY2021 Energy and Water Development Appropriations, H.Rept. 116-
449, accompanying H.R. 7613.
73 House Appropriations Committee, Report on FY2021 Energy and Water Appropriations, H.Rept. 116-449,
accompanying H.R. 7613.
74 DOI, Bureau of Reclamation, Budget Justification and Performance Information FY2021, Bureau of Reclamation ,
2020, at https://www.usbr.gov/budget/2021/FY_2021_Budget_Justifications.pdf. Hereinafter, Reclamation, 2021
Budget Justification.
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Owens Lake Air Quality Mitigation Program.75 That program is conducting compliance actions
under the Clean Air Act and reports that air quality mitigation for exposed lake beds costs
approximately $38.0 mil ion per square mile (averaged over al types of mitigation), with annual
maintenance costs of approximately $500,000 per square mile.76
Conclusion
In the future, Congress may be asked by various stakeholders to make additional commitments to
Salton Sea restoration, potential y in the form of additional appropriations to one or more federal
agencies to supplement or match state expenditures on the SSMP or specific directives related to
federal restoration efforts. Some prior commitments, such as those in DOI’s 2016 MOU with the
State of California, may not be fully realized without additional funding and authorities from
Congress. However, the extent to which this is the case remains unclear.
Congress may be interested in answers to several questions related to Salton Sea restoration and
the effects of Salton Sea ecosystem degradation on environmental contaminants and human
health. These questions may include the following:
 What are the effects of exposed playa on air quality and, consequently, on human
health in the region? What is the federal responsibility for mitigating these
effects?
 How do decisions related to water management in the Colorado River Basin
affect the health of the Salton Sea ecosystem?
 What is the preferred federal role in implementing the SSMP? Does the project
require additional funding, authorities, or other congressional direction?
 What are the cost, content, and duration of long-term restoration plans currently
under way in the SSMP? How wil these plans restore the Salton Sea ecosystem,
mitigate the effects of exposed playa, and conserve species?

75 For more information on the Great Basin Unified Air Pollution Con trol District’s Owens Lake Air Quality Mitigation
Program, see https://www.gbuapcd.org/.
76 “Lower Colorado Basin” in Reclamation, 2021 Budget Justification, 2020, p. 41.
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Appendix. Chronology of Events in the Salton Sea
Chronology of Selected Historical Events Related to the Salton Sea
Year
Historical Event
10,000 BC
Native Americans first occupy the Salton Basin.
AD 700
Lake Cahuil a is formed in the Salton Basin and proceeds to dry out and fil up four times.
1500 (approx.) Large inflow of water fil s the Salton Basin from the Gulf of California. It is 26 times the size of
the Salton Sea.
1600
Salton Basin dries out.
1840–1870
Flooding from the Colorado River is recorded in the Salton Basin.
1876
U.S. government establishes the Torres-Martinez Desert Cahuil a Indian Reservation with a
grant of 640 acres.
1891
20,000 acres of land on the northern side of the Salton Basin provided to the Torres-Martinez
Band of Desert Cahuil a Indians.
1901
Imperial Canal brings water from the Colorado River to the Imperial Val ey.
1905
The Salton Sea is created in the basin by a levee break in the Colorado River.
1909
The U.S. government reserves in trust nearly 10,000 acres of land under the Salton Sea for the
benefit of the Torres-Martinez Indians.
1924
President Calvin Coolidge issues Public Water Reserve Orders 90 (issued in 1924) and 114
(issued in 1928) setting aside lands under the Salton Sea as a permanent drainage reservoir for
agricultural and surface water runoff from the Imperial and Coachel a Val eys.
1928
Boulder Canyon Project Act (P.L. 70-642) authorizes the construction of the Boulder Dam and
the Al American Canal (expected to control the Colorado River and stop flooding).
1930
Salton Sea National Wildlife Refuge established. It covers an area of 35,000 acres. Due to
flooding and a rise in sea level since 1930, only 2,000 acres remain uncovered by salty water.
The refuge was renamed to Sonny Bono Salton Sea National Wildlife Refuge in 1998.
1967
The Yuma clapper rail is listed as an endangered species in the United States. Its range includes
the Salton Sea.
1969
A federal-state reconnaissance investigation studies water quality problems in the Salton Sea.
Based on this study, a feasibility study of management plans was authorized in 1972.
1970
The brown pelican is listed as an endangered species. Its range includes the Salton Sea. (In 1985,
the species was delisted in the East, but it is stil being monitored.)
1974
Federal-state feasibility study, which provided alternatives for lowering the salinity and
maintaining water levels in the Salton Sea, is completed.
1986
The desert pupfish is listed as a federal y endangered species in its entire range, which includes
the Salton Sea.
1992
150,000 eared grebes die, garnering national attention for the Salton Sea. Cause of their deaths
is unknown.
Title XI of the Reclamation Projects Authorization and Adjustment Act of 1992 ( P.L. 102-575)
authorizes Bureau of Reclamation (Reclamation) to conduct research on methods to control
salinity levels, provide habitat to endangered species, enhance fisheries, and protect recreational
values of the Salton Sea. A total of $10 mil ion is authorized for this effort.
1993
The Salton Sea Authority is formed among Riverside and Imperial Counties and the Coachel a
Val ey Water and Imperial Irrigation Districts. The goal is to coordinate activities that relate to
improving water quality, stabilizing water levels, and enhancing economic and recreational
activities in and around the Salton Sea.
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Year
Historical Event
1998
The Salton Sea Reclamation Act of 1998 (P.L. 105-372) authorizes the Secretary of the Interior
to complete studies of management options to al ow the use of the Salton Sea to continue and
to stabilize salinity and surface elevation, as wel as to maintain fish and wildlife populations and
enhance the potential for recreation and economic development.
1999
Water Resources Development Act of 1999 (P.L. 106-53) authorizes the Secretary of the Army
to provide technical assistance to federal, state, and local agencies to implement restoration
measures in the Salton Sea and to determine a plan in which the U.S. Army Corps of Engineers
could assist others in restoring the sea.
2000
The Department of the Interior (DOI) submits a draft environmental impact
statement/environmental impact report and a strategic science plan for restoring the Salton Sea.
DOI establishes the U. S. Geological Survey (USGS) Salton Sea Science Office to provide
continuity of the science effort, effectiveness of science undertaken in support of the restoration
project, and efficiency of operations in serving management needs. (In FY2016, the office was
closed and its function was consolidated with the DOI Region 8 USGS Regional Office in
Sacramento.)
Title VI of the Torres-Martinez Settlement Act (P.L. 106-568) provides compensation to the
Torres-Martinez Desert Cahuil a Indians for their submerged land. A total of $14 mil ion was
authorized, $10 mil ion from the federal government and $4 mil ion from water districts.
2003
Quantitative Settlement Agreement is finalized, requiring California to reduce its use of
Colorado River water to 4.4 mil ion acre-feet per year, as required in the Law of the River.
Implementation of the agreement required, among other things, long-term water transfers that
indirectly reduced long-term irrigation runoff into the sea.

Reclamation submits the Salton Sea Study Status Report, which contains various proposals for the
ful or partial restoration of the sea.
2004
Water Supply, Reliability, and Environmental Improvement Act (P.L. 108-361) requires the
Secretary of the Interior to complete a feasibility study on a preferred alternative for Salton Sea
restoration.
2006
Reclamation and the USGS construct shal ow habitat pools on the southern end of the Salton
Sea.
2007
Water Resources Development Act of 2007 (P.L. 110-114) authorizes $30 mil ion for Salton Sea
restoration pilot projects.

Reclamation and DOI release Restoration of the Salton Sea.
2013
USACE, in conjunction with state agencies, releases final environmental impact
report/environmental impact statement for the Salton Sea Species Conservation Project.
2015
Salton Sea Restoration and Renewable Energy Initiative proposed by Imperial Irrigation District.
Described design concepts for restoration, air quality mitigation, geothermal development, and
other renewable energy technologies.
2016
DOI signs a memorandum of understanding with the State of California agreeing to participate
in Salton Sea restoration efforts.
2016
Senate resolution on Salton Sea and Tributaries, Riverside, Imperial, and San Diego Counties,
California, by the Senate Environment and Public Works Committee, authorizes USACE to
review the Chief of Engineers’ reports on flood control for al streams in the San Diego and
Imperial Counties, CA, flowing into the Salton Sea, along with other pertinent reports, to
determine the advisability of federal participation in providing improvements for flood risk
management, ecosystem restoration, and other water- and land-related resources for the Salton
Sea and its vicinity.
USACE is authorized to conduct ecosystem restoration in the Salton Sea through §3032 of P.L.
110-114, as amended. USACE is authorized to implement project-specific restoration plans and
projects consistent with previously published studies to restore the Salton Sea.
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2017
State of California releases the Salton Sea Management Program (SSMP), a comprehensive,
multiphase restoration plan for the Salton Sea.
2019
Colorado River Drought Contingency Plan Authorization Act (P.L. 116-114) passes.
Reclamation and the Colorado River Basin states finalize drought contingency plans (DCPs) for
the Upper and Lower Colorado River Basins. The DCPs include commitments to curtail water
deliveries under some scenarios, including, for the first time, cutbacks to California’s deliveries if
Lake Mead water levels drop below a certain elevation.

Author Information

Pervaze A. Sheikh
Charles V. Stern
Specialist in Natural Resources Policy
Specialist in Natural Resources Policy

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Congressional Research Service
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