Accompanying content for
Forgotten Waters
part of the Water Stories art show at The Photographer's Eye gallery in Escondido, CA.
Last updated in July 2025.
Key Message
The Water Crisis in Numbers
Colorado River flow down 20% since 2000 - half due to rising temperatures. [1] [2]
1.5 million acre-feet annual structural deficit - The Colorado River compact promised more than the river delivers. [3] [4] [5]
28 million acre-feet of groundwater lost since 2003 - equal to Lake Mead's capacity. [6]
Lake Mead and Lake Powell reservoirs are at 32% capacity down from 95% full in the early 2000s. [7] [8]
The Forgotten Communities
Native tribes hold rights to 25% of Colorado River water but most can't access it. [9] [10]
Colorado River Indian Tribes have senior rights to 717,000 acre-feet - nearly 1/3 of Arizona's allocation. [11]
Tribal lands were cut off from historical river flows by upstream dams and diversions [12]
Conservation Success Stories
Per capita water use in the San Diego region has declined 52% since 1990, from 235 gallons per capita per day (GPCD) to 112 GPCD in 2023. Over the last 20 years, potable water use fell by over 30 percent, even though the region’s population grew by about 17 percent. [13]
Between 2002 and 2023 Southern Nevada reduced per capita water use by 58% from 211 to 89 GPCD despite population increase by 52%. Conservation goal is 86 GPCD by 2035. [14]
Southern Californians reduced per person water use by 45% since 1990. The region used a record low 114 GPCD in 2023, down from 209 GPCD in 1990. [15]
In 2017, Los Angeles cut water use below 1970 levels despite growing by 1 million people. The city’s GPCD dropped by 40% from 173 in 1990 to 104 in 2017. [16]
San Diego gains 200,000 acre-feet annually through Imperial Valley conservation transfers. [17]
Agriculture Numbers
79% of Colorado River water goes to agriculture - mostly livestock feed crops like alfalfa [18]
6.24 million acre-feet used for alfalfa and other hay - enough for 40 million people's household needs for 3.5 years [19]
40% of alfalfa in California in 2020 was exported internationally, while the Southwest faces severe drought [20] [21] [22]
Why "Forgotten Waters"?
The title "Forgotten Waters" speaks to one of the most profound injustices in American water policy: the exclusion of Native American tribes from the 1922 Colorado River Compact that divided the river's waters, despite their holding rights to approximately 25% of the Basin's average annual water supply. Native Americans weren't considered U.S. citizens when the Colorado River agreement was signed, and were excluded from this agreement with no direct say in how the water they relied on for millennia was divided.
Today, despite owning rights to about a quarter of the river, for most tribes these are only paper rights, not amounting to water they can actually use. This forgotten legacy persists as massive water infrastructure—Glen Canyon Dam, Hoover Dam, hundreds of miles of concrete aqueducts, and sprawling irrigation canals—delivers water to distant cities and industrial agriculture while many tribal communities lack basic access to clean water.
The scale of this infrastructure is staggering. The Colorado River system includes two massive reservoirs (Lake Powell and Lake Mead), major aqueducts like the Colorado River Aqueduct stretching 240 miles to Los Angeles, and the Central Arizona Project's 336-mile canal system. Yet this elaborate network of concrete and steel was built around the systematic exclusion of those with the oldest water rights in the basin.
The Southwest's Water Crisis: A Perfect Storm
Water has become the defining issue of the American Southwest due to an unprecedented combination of climate change, megadrought, and over-allocation. The region is experiencing what scientists call a "megadrought"—the worst 20-year period of water scarcity in over 1,000 years.
The numbers tell a stark story. Snowpack in the Rocky Mountains, which feeds the Colorado River, has declined dramatically over the past 25 years. Even during recent "good" snow years, the reservoirs haven't refilled. Current projections show Lake Mead's water levels at 1,062 feet above sea level as of January 2025, and Lake Powell's at 3,574 feet. The combined storage of Lake Powell and Lake Mead is at just 37% of capacity.
What makes this crisis particularly severe is that the Colorado River was over-allocated from the beginning. The 1922 Colorado River Compact divided water based on unusually wet years, creating a system that promised more water than the river typically provides. Climate change has intensified this fundamental miscalculation, with rising temperatures increasing evaporation rates and reducing snowpack in the river's headwaters.
The Numbers: Understanding Colorado River Allocations
The Colorado River Compact of 1922 divided the river's flow between the Upper Basin states (Colorado, Wyoming, Utah, and New Mexico) and Lower Basin states (California, Arizona, and Nevada). Each basin was allocated 7.5 million acre-feet (MAF) annually—a total of 15 MAF. One acre-foot equals roughly 326,000 gallons, enough water for two typical American families for a year.
Lower Basin Allocations
California: 4.4 MAF (the largest single allocation)
Arizona: 2.8 MAF
Nevada: 0.3 MAF
Mexico: 1.5 MAF (added 1944)
California's Water Distribution
California's 4.4 MAF allocation is divided among:
Agriculture: Approximately 3.2 MAF (over 70% of the state's allocation)
Imperial Irrigation District (IID): 3.1 MAF (the largest single user, primarily for desert farming)
Metropolitan Water District (serving Los Angeles area): 1.2 MAF
San Diego County Water Authority: 0.28 MAF
Municipal Allocations
Major Southwestern cities receive:
Los Angeles (via Metropolitan Water District): ~0.5 MAF
San Diego: ~0.2 MAF from Colorado River, plus additional water from conservation projects
Phoenix: ~1.4 MAF
Tucson: ~0.14 MAF
San Diego's Water Strategy
San Diego has pioneered water independence through conservation and alternative sources. The city has secured additional water through:
The Quantification Settlement Agreement, which transfers agricultural water from Imperial Valley
The nation's largest seawater desalination plant in Carlsbad
Extensive water recycling programs
Aggressive conservation measures that have reduced per-capita water use by over 40% since the 1990s
The Agriculture Factor
Agriculture consumes roughly 70% of all Colorado River water. The Imperial Valley alone — a desert region that produces much of America's winter vegetables — uses more Colorado River water than the entire state of Nevada. This agricultural use occurs in one of the hottest, driest regions of North America, where evaporation rates are extreme and crops require intensive irrigation.
Tribal Rights: The Forgotten 25%
Twenty-two Tribal Nations hold rights to use approximately 3.2 million acre-feet of Colorado River water annually — yet much of this remains unrealized due to lack of infrastructure and legal barriers. These rights are based on the "Winters Doctrine," which recognizes that when reservations were established, sufficient water was implicitly reserved for tribal needs.
The "Forgotten Waters" exhibit reveals how this complex web of allocations, infrastructure, and inequity has created a water system that serves distant cities and industrial agriculture while leaving behind those with the oldest and strongest legal claims to the river. As Lake Powell and Lake Mead continue to shrink, these forgotten waters—and the communities they should serve—become increasingly visible in their absence.
The massive concrete infrastructure captured in these photographs—from the Colorado River Aqueduct's pumping stations to the sprawling canals of the Central Arizona Project—represents both an engineering marvel and a monument to exclusion. Understanding these numbers and allocations helps us see not just the scale of the crisis, but the profound choices embedded in concrete about who gets water and who goes without.
Colorado River Aqueduct
The Colorado River Aqueduct is an impressive 242-mile water conveyance system built during the Great Depression in the 1930s that transports millions of gallons of water daily from the Colorado River to Southern California. The system operates through five major pumping plants - Whitsett, Gene, Iron Mountain, Eagle Mountain, and Hinds - each designed with nine pumps and engineered to lift water over varying elevations totaling over 1,600 feet. These plants, with their original equipment dating back nearly a century, have been carefully maintained and upgraded over time, moving water through a complex network of open canals, tunnels, and siphons before it flows by gravity to the terminal reservoir at Lake Mathews in Riverside County.
This vital infrastructure serves approximately 19 million people across Southern California, providing roughly 25% of the region's water supply and enabling the massive population and economic growth of the 20th century. However, the system now faces significant challenges from drought conditions, climate change, and competing demands on the Colorado River. Despite these challenges, water conservation efforts have proven successful - Los Angeles has achieved remarkable efficiency gains, with per capita water use dropping 40% below 1970 levels even as the population grew by over one million people, thanks to conservation programs, rebates, and landscape ordinances that have collectively saved about 25,000 acre-feet of water annually since 2010.
All-American Canal
The 82-mile All-American Canal, located in the southeastern corner of California, conveys water from the Colorado River to California’s Imperial Valley. The 123-mile Coachella Canal is a branch of the All-American Canal that delivers water to California’s Coachella Valley.
The Imperial Irrigation District (IID) conserved water transfer agreement provides 200,000 acre-feet of water a year for the San Diego region through water conservation measures in Imperial Valley. It is the largest agriculture to urban water transfer in the nation.
The All-American and Coachella Canal lining projects are conserving 77,700 acre-feet of water each year significantly reducing seepage through the earthen canals. Under the canal lining projects, approximately 23 miles of parallel, concrete-lined canal were constructed next to the original All-American Canal, and 35 miles of parallel, concrete-lined canal were constructed next to the original Coachella Canal.
Additionally, 16,000 acre-feet of conserved water per year is sent to several bands of Mission Indians in northern San Diego County – known as the San Luis Rey Indian settlement parties – settling a water rights dispute and decades of litigation with the federal government.
Las Vegas, Nevada
The current condition in Lake Mead resulted in a Tier 1 water shortage for Lower Basin operations, reducing Nevada's consumptive Colorado River water use annually by 21,000 acre feet. The Tier 1 shortage will remain in effect through 2025. However, Nevada is not currently using its full Colorado River allocation. By the end of 2023, Nevada's consumptive Colorado River Water use was 187,000 acre-feet. This amount is below any Colorado River water supply reduction under existing rules.
Conservation efforts have helped the community reduce its per capita water use by 58 percent between 2002 and 2023, even as the population increased by more than 786,000 residents during that time. The consumptive use of Colorado River water was reduced by approximately 138,000 acre-feet per year.
The Southern Nevada Water Authority (SNWA) has banked approximately 2.2 million acre-feet of water through 2023. This amount is twelve times Nevada’s 2023 consumptive Colorado River water use.
The SNWA completed construction of the Low Lake Level Pumping Station at Lake Mead in 2020. The pumping station works with SNWA’s Lake Mead Intake No. 3 to preserve Southern Nevada’s access to Colorado River water supplies to a Lake Mead elevation of 875 feet. This elevation is approximately 20 feet below the minimum elevation that Hoover Dam can release water downstream.
Lake Havasu
Lake Havasu, created by Parker Dam, is about 45 miles long and can store nearly 211 billion gallons of water. It has become a major recreational destination known for fishing, boating, and water sports. The dam and lake system also play a crucial role in flood control and water management along the lower Colorado River, helping to regulate water flow and ensure reliable water supply to surrounding communities and agricultural areas.
Parker Dam is a concrete arch-gravity dam situated on the Colorado River between Arizona and California, about 155 miles downstream from Hoover Dam. Completed in 1938, it's often called "the deepest dam in the world" because 73% of its 320-foot structural height is below the riverbed due to the need to reach bedrock through the river's deep sediment. The dam's primary purpose was to create Lake Havasu, which serves as a reservoir and pumping station for 1) the Colorado River Aqueduct (CRA) that supplies water to Southern California and 2) the Central Arizona Project (CAP), a canal diverting water to Tucson and Phoenix in Arizona.
Native Tribes and Agriculture (California, Arizona)
«So-called forage crops like alfalfa and Bermuda grass, which are used to feed livestock, mainly cattle, require mind-altering amounts of water to cultivate.»
The Colorado River Basin is facing a severe water crisis, largely driven by agricultural practices unsuited to the arid climate. That includes a technique called “flood irrigation,” which is exactly what it sounds like: watering hundreds of alfalfa acres at a time by briefly flooding the field. About 79% of the river's water goes to crop irrigation, with 70% of that specifically used for livestock feed crops like alfalfa. In 2022 alone, alfalfa farming consumed 6.75 million acre feet of water across the seven basin states - enough to meet the indoor household water needs of 40 million people who rely on the Colorado River system for municipal water for three and a half years.
The agricultural crisis is exacerbated by multiple factors: inefficient irrigation practices like flood irrigation and central pivot sprinklers, particularly in arid regions like California's Imperial Valley, which receives only three inches of rain annually but requires 46 inches for alfalfa growth, climate change impacts that have reduced river flow by 20% since 2000, and the continued growth of alfalfa production, including exports. 40% of the alfalfa grown in California in 2020 was shrink-wrapped, containerized, and shipped internationally. Proposed solutions include restricting alfalfa exports, and transitioning to geographically appropriate crops.
The Fort Yuma-Quechan Reservation is located near Yuma, Arizona and includes 45,000 acres along the Colorado River. The reservation encompasses a portion of the ancestral home of the Quechan People. Their aboriginal villages were located in or near the Colorado River’s floodplain, which allowed annual floods to deposit rich soil from upriver. This ended with development of dams and diversions upstream from the Quechan homeland, which essentially cut off the historical flows to the area.
The Fort Mojave Indian Reservation is located along the Colorado River in the vicinity of Needles, California. Agriculture provides the basis for the Fort Mojave economy and 15,000 acres of land are under cultivation. Crops grown include staples like cotton, alfalfa and wheat. Living along the banks of the Colorado River, the Mojave Indians are the Pipa Aha Macav – The People by the River. Mojave culture traces the earthly origins of its people to Spirit Mountain, the highest peak in the Newberry Mountains, located northwest of the present reservation inside the Lake Mead National Recreation Area.
The Colorado River Indian Reservation is located in between Blythe and Parker. The river serves as the focal point and lifeblood of the area. The fertile river bottom lands and available water allow the production of agricultural and produce such as cotton, alfalfa, wheat, feed grains, lettuce and melons. Approximately 84,500 acres are now under cultivation. The Colorado River Indian Tribes have senior water rights to 717,000 acre feet of the Colorado River, which is almost one-third of the allotment for the state of Arizona.
Mexico: The Forgotten Nation
Mexico's exclusion from the original 1922 Colorado River Compact represents another layer of the "forgotten waters" story. The Mexican Water Treaty of 1944 committed the U.S. to deliver 1.5 million acre-feet of water to Mexico on an annual basis, but this came 22 years after the initial compact that divided the river among U.S. states. Negotiations initiated in 1941 resulted in the 1944 Treaty that linked the waters of the Rio Grande River with the Colorado River waters.
The consequences of Mexico's delayed inclusion have been severe. By the early 2000s, researchers estimated the delta had lost 90% of its forests and wetlands because dams and water withdrawals had drained the lower Colorado. Less than 80 years ago, the mighty Colorado River flowed unhindered from northern Colorado through the Grand Canyon, Arizona, and Mexico before pouring into the Gulf of California, but now irrigation and urban water needs prevent the river from reaching its final destination.
Recent restoration efforts have begun to address this ecological catastrophe. For the first time in history, the U.S. and Mexico have sent a modest volume of water into the Colorado River Delta in the form of a temporary "pulse flow," which mimics the natural spring floods that once nourished the delta. These collaborative efforts represent a recognition that the river's "forgotten waters" extend beyond tribal communities to include an entire nation and ecosystem downstream.
The "Forgotten Waters" exhibit reveals how this complex web of allocations, infrastructure, and inequity has created a water system that serves distant cities and industrial agriculture while leaving behind those with the oldest and strongest legal claims to the river. As Lake Powell and Lake Mead continue to shrink, these forgotten waters—and the communities they should serve—become increasingly visible in their absence.
The massive concrete infrastructure captured in these photographs—from the Colorado River Aqueduct's pumping stations to the sprawling canals of the Central Arizona Project—represents both an engineering marvel and a monument to exclusion. Understanding these numbers and allocations helps us see not just the scale of the crisis, but the profound choices embedded in concrete about who gets water and who goes without.
References
[1] “A River in Crisis - Dire conditions in the Colorado River Basin call for collaborative solutions”. August 28, 2022. Online at: https://www.nature.org/en-us/about-us/where-we-work/priority-landscapes/colorado-river/colorado-river-in-crisis
[2] “Rapid Decline - Scientist describes impacts of climate change on the Colorado River and its 40 million users”. By Coleman Cornelius. February 13, 2023. Online at: https://magazine.csusystem.edu/2023/02/13/rapid-decline
[3] Tribal Interests in the Future of the Colorado River. May 19, 2025. By Alice Walker. Online at: https://narf.org/tribal-interests-colorado-river
[4] Management of the Colorado River: Water Allocations, Drought, and the Federal Role. March 27, 2025. By Hite, Kristen; Sheikh, Pervaze A.; Stern, Charles V. Online at: https://www.congress.gov/crs-product/R45546
[5] Q&A: The Colorado River in 2025 - "Hydrology is central," the promises of the Colorado River Compact + Trump 2.0. By Daniel Rothberg. February 12, 2025. Online at: https://www.westernwaternotes.com/p/q-and-a-the-colorado-river-in-2025
[6] Groundwater in the Colorado River basin won't run out — but eventually we won’t be able to get at it, scientists warn. By Chris Simms. June 13, 2025. Online at: https://www.livescience.com/planet-earth/rivers-oceans/groundwater-in-the-colorado-river-basin-wont-run-out-but-eventually-we-wont-be-able-to-get-at-it-scientists-warn
[7] Critical reservoirs Lakes Mead, Powell hit 'alarmingly low levels' again - A report shows that both Mead and Powell have "reached alarmingly low levels, holding just one-third of their usual capacity" By Doyle Rice. June 28, 2025. Online at: https://www.usatoday.com/story/news/nation/2025/06/28/water-crisis-update-lakes-mead-powell-hit-alarmingly-low-levels/84384030007
[8] Current water levels and capacity data at https://lakemead.water-data.com for Lake Mead and https://lakepowell.water-data.com for Lake Powell.
[9] Historically excluded from Colorado River policy, tribes want a say in how the dwindling resource is used. Access to clean water is a start. By Michael Elizabeth Sakas. December 7, 2021. Online at: https://www.cpr.org/2021/12/07/tribes-historically-excluded-colorado-river-policy-use-want-say-clean-water-access
[10] Colorado River crisis giving tribes new opportunities to right century-old water wrongs. By Kalen Goodluck. May 11, 2022. Online at: https://watereducationcolorado.org/fresh-water-news/colorado-river-crisis-giving-tribes-new-opportunities-to-right-century-old-water-wrongs
[11] Inter Tribal Council of Arizona - Colorado River Indian Tribes. Online at: https://itcaonline.com/member-tribes/colorado-river-indian-tribes
[12] The Ten Tribes Partnership - Quechan Indian Tribe. Online at: https://tentribespartnership.org/tribes/fort-yuma-quechan-indian-tribe
[13] San Diego County Water Authority - Water-Use Efficiency. January 2025. Online at: https://www.sdcwa.org/wp-content/uploads/2020/11/wateruseefficiency-fs.pdf
[14] Southern Nevada Water Authority - 2025 Water Resource Plan. Online at: https://www.snwa.com/assets/pdf/water-resource-plan-2025.pdf
[15] “Southern Californians’ per person water use drops to lowest in 35 years”. Metropolitan Water District. January 30, 2025. Online at: https://www.mwdh2o.com/press-releases/southern-californians-per-person-water-use-drops-to-lowest-in-35-years
[16] Los Angeles Department of Water and Power (LADWP), Water Conservation Potential Study, September 2017. Online at: https://www.ladwp.com/sites/default/files/2023-08/Water%20Conservation%20Study%20June%202018.pdf
[17] San Diego County Water Authority - Colorado River. Online at” https://www.sdcwa.org/your-water/imported-water-supplies/colorado-river
[18] “The Colorado River Is Shrinking. See What’s Using All the Water.” New York Times. By Elena Shao. May 22, 2023. Online at: https://www.nytimes.com/interactive/2023/05/22/climate/colorado-river-water.html
[19] Hay grown for cattle consumes nearly half the water drawn from Colorado River, study finds. Los Angeles Times. By Ian James. March 28, 2024. Online at: https://www.latimes.com/environment/story/2024-03-28/alfalfa-hay-beef-water-colorado-river
[20] Hay – yes, hay – is sucking the Colorado River dry. By Samuel Shaw. June 5, 2023. Online at: https://www.hcn.org/articles/south-colorado-river-hay-yes-hay-is-sucking-the-colorado-river-dry
[21] Booming demand for hay in Asia, Middle East driving agribusiness in the California desert. By Ian James. The Desert Sun. September 28, 2017. Online at: https://www.desertsun.com/story/news/environment/2017/09/28/booming-demand-hay-asia-middle-east-driving-agribusiness-california-desert/702400001
[22] Cherish that hamburger. It cost a quarter of the Colorado River, according to researchers. By Shannon Mullane. April 4, 2024. Online at: https://coloradosun.com/2024/04/04/research-colorado-river-water-use-cherish-hamburger
Other References
[State of the Water 2024] Story map by Stefan Frutiger. Online at: https://storymaps.arcgis.com/stories/0fce1d9f61d249e0b87ca4f7a7d0f784