Colorado River

Colorado River

Colorado River: Working Toward A New Era of Sustainability 

For decades, the Colorado River has been known as the workhorse of the West, sustaining communities and economies across seven states and two nations, including nearly 19 million people in Southern California. Collaboration and cooperation have allowed the river’s resources to be shared.

7

40

5

30
States  Million
People 		 Million Acres
of Farmland		 Federally
Recognized
Tribes

But after years of reduced flows, the river’s future is uncertain. If significant action isn’t taken to permanently reduce demands, one of Southern California’s most important water supplies could be in jeopardy. 

Metropolitan and Colorado River water users across the Southwest are facing this uncertain future as they attempt to negotiate a new set of rules that will guide the river’s operations starting in 2027. Those negotiations require tough decisions: How should the river’s dwindling supplies be shared? How can we best mitigate the impacts of cuts? How must urban landscapes and rural farmlands change so that the Southwest can endure? 

One thing is clear – everyone who uses Colorado River water will have to do more to use less.

 

40 million people rely on water from the Colorado River. 19 million of them live in urban Southern California.

Reservoirs at Risk

At the heart of the river system, and embodying its struggles, sit Lake Mead and Lake Powell, the two largest reservoirs in the United States. Over the past two decades, drier conditions have reduced the average snowmelt and runoff that once fed the river. Storage in these giant reservoirs has dropped.

Today, at least 20% less water flows through the Colorado River system annually than was expected 100 years ago. Even less is expected in the future.

Cities and farms across the Southwest have taken important steps to reduce their demands on the river and minimize the declines of the reservoirs. But it is clear additional conservation is needed throughout the Basin. Lake Mead and Lake Powell remain at risk if significant long-term reductions in use aren’t made. If the reservoirs get too low, restricting the amount of water that can pass through the dams, power generation would be severely impacted.

Lake Mead: Decades of Decline

 

Lake Mead Chart

Negotiating Post-2026 Solutions

Metropolitan is working with Colorado River water users across the Basin to try and develop a consensus agreement for post-2026 operations that is supported by all seven Colorado River Basin states. In these negotiations, Metropolitan recognizes that it, like all Colorado River users, is going to have to reduce its water use. But Metropolitan is also working to develop flexibility in the system that allows those reductions to happen with the least amount of pain – allowing users access to water when they need it most and store water in the system when they don't.

November 2025: Deadline from the U.S. Bureau of Reclamation for the seven states to develop a consensus framework agreement.

If the Basin states can’t reach consensus, they move one step closer to seeking resolution through the courts – a path that could take years and have myriad unintended consequences.

A long-term path to sustainability includes:

  • Shortage Sharing: Significant reductions in water use, shared by all water users
  • Storage and Flexibility: Ability to store water in Lake Mead and flexibility to use it when necessary, filling the Colorado River Aqueduct or other places water is needed when other supplies are limited
  • Augmentation: Development of new supplies, like Pure Water Southern California, and ability to invest in new supplies in other states and share the water that is developed
  • Power Generation: Measures to protect power generation at Lake Mead’s Hoover Dam and Lake Powell’s Glen Canyon Dam
  • Certainty: Predictability on how much supply water users can reliably expect from the Colorado River
Lake Mead’s Bathtub Ring Photo

Lake Mead’s Bathtub Ring. Photo courtesy of DWR.

Offering Real Reductions, Proposing Realistic Solutions

To build a more sustainable Colorado River, agreements must be forged at various levels among many partners:

  • Among all Colorado River Basin states – California, Arizona, Nevada, Colorado, New Mexico, Utah, Wyoming – about how needed reductions will be divided between the Upper Basin and the Lower Basin and how water will be released from Lake Powell to Lake Mead
  • Between the United States and Mexico over how the River will be shared
  • Among California water users about how the state’s reductions will be divided.
  • All of these negotiations also include discussions about how water can be stored in Lake Mead and Lake Powell, how interstate exchanges can occur, and other strategies to improve the river’s sustainability

As part of these discussions, the Lower Basin and California have already made preliminary offers to significantly reduce their annual Colorado River water under a broad range of conditions:

1.25 million acre-feet

440,000 acre-feet
Reductions proposed by the Lower Basin Reductions proposed by California

Lower Basin partners also recognize that additional reductions will be needed by all the Basin states if conditions worsen.

Law of the River  

How the Colorado River’s resources are divided among the seven Colorado River Basin states and Mexico is governed by a series of interstate compacts, statutes, Supreme Court decrees, a treaty with Mexico, contracts and regulatory guidelines - all collectively known as the Law of the River.

1922

Divided right to use Colorado River water between Upper and Lower Basins, apportioning 7.5 million acre-feet (maf) to each basin in perpetuity.

Colorado River Compact

1922 Colorado River Compact

1928

Authorized construction of the Hoover Dam and allocated the 7.5 maf apportionment among the Lower Basin states, giving California 4.4 maf/year.

Boulder Canyon Project Act

Hoover Dam Construction

1931

Established priority system for California’s Colorado River water users. Agricultural agencies received higher priorities than Metropolitan.

California Seven Party Agreement

1928 Boulder Canyon

1944

Guarantees delivery of 1.5 maf to Mexico annually under normal supply years.

Mexican Water Treaty

Mexican Treaty

1956

Authorized the construction of Upper Basin river storage and power production, facilities including Glen Canyon Dam (Lake Powell).

Colorado River Storage Project Act

Glen Canyon Dam Construction

1963

Supreme Court settled the allocation of the Lower Basin’s 7.5 maf apportionment. Decision recognized the Secretary of the Interior’s authority to determine when there are surpluses and shortages in Lower Basin.

Arizona v. California

1963 Arizona V California

1968

Authorized the construction of the Central Arizona Project. To gain congressional support, CAP agreed to lower priority than California water users.

Colorado River Basin Project Act

Gila River Siphon Construction

1970

Provided for the coordinated operation of reservoirs in the Upper and Lower basins and set conditions for water releases from Lake Powell to Lake Mead.

Coordinated Long-Range Operation

Glen Canyon Dam Lake Powell

2001

Established surplus criteria in the Lower Basin through 2016. Provided targets for reducing California’s consumptive use to 4.4 maf.

Interim Surplus Guidelines

Parkerdam Scenic Rainbow

2003

Settled water rights disputes among California agencies and established agricultural water use caps to provide for transfers to urban users.

Quantification Settlement Agreement

Coachella Canal Lining

2007

Established shortage criteria in the Lower Basin through 2026. Established the Intentionally Created Surplus program.

Interim Shortage Guidelines

Lake Mead

2019

Lower Basin states agreed to store defined volumes of water in Lake Mead at certain lake levels. Upper Basin states gained tools to maintain higher levels in Lake Powell.

Drought Contingency Plan

2019 Colorado River Drought Contingency Plans Signing Ceremony
1922
1928
1931
1944
1956
1963
1968
1970
2001
2003
2007
2019

Part of the Solution: A History of Reductions

When California commits to reductions in water deliveries, it delivers. For more than 20 years, the state has shown it can reduce its reliance on the Colorado River, thanks to hard-earned partnerships and billions of dollars in investments.

 

Immediate Conservation to Stabilize Lake Mead  

When Lake Mead reached record low levels in 2022, the Lower Basin worked immediately to help stabilize the reservoir, committing to add an additional 3 million acre-feet of water by the end of 2026, benefitting the entire Colorado River system. More than half – 1.6 million acre-feet – is coming from California. States are on track to not only meet that goal, but exceed it.

 

500,000 acre-feet

340,000 acre-feet

Total contribution from Metropolitan to Lake Mead

2023-2024*

Contribution from Metropolitan agricultural partners, through Met conservation programs, 2023-2025

*Metropolitan expects to contribute additional water in 2025, however the volume is subject to operations over the remainder of the year.

 

Metropolitan’s direct contribution is the result of investments in conservation and local resources, including $55 million in water-efficiency programs in fiscal 2025-26, helping Southern California communities lower their demands on the river.

The contribution from our agricultural partners resulted from Metropolitan temporarily turning over to the U.S. Bureau of Reclamation its conservation programs with Bard Water District, Palo Verde Irrigation District and the Quechan Tribe. Reclamation funded these fallowing programs and forbearance agreements through the Lower Colorado River Basin System Conservation and Efficiency Program, and the conserved water stayed in Lake Mead for the benefit of all Colorado River users.

Palo verde crops

Collaboration Across California

The successful short-term water savings over the past three years builds on decades of work by Metropolitan and its agricultural partners to reduce their Colorado River water use.

Metropolitan’s path to sustainability was first laid in 2003, when California permanently lost access to 800,000 acre-feet of surplus Colorado River water almost overnight after Arizona and Nevada began using their full apportionments. The majority of those reductions fell on Metropolitan – cutting our supply in half.

While it was an enormous challenge, it launched California into a new era of collaboration between agricultural and urban water agencies. The groundbreaking 2003 Quantification Settlement Agreement and related agreements set aside decades-old disputes and facilitated water transfers from farms to cities, funded lining of the All-American and Coachella canals to reduce seepage and led to new agricultural conservation in California and partnerships with Metropolitan.

Finding Mutual Benefits:
Ag-Urban Partnerships

 

Most of the 2003 cuts fell on Metropolitan, as the junior priority user in California. To make up for these lost supplies, Metropolitan has invested $2 billion in partnerships forged with agricultural agencies. Through these partnerships, Metropolitan pays participating farmers to conserve water while also ensuring the continued success of the agricultural economy.

The water saved through these programs – which include partial land fallowing, crop rotation and irrigation improvements – is then made available to Metropolitan. These efforts provide Metropolitan greater flexibility to plan for and withstand times of shortage. Today, half of the water Metropolitan receives from the Colorado River is available through these agreements.

Bard Water District 
Metropolitan pays farmers to not plant lower-value, water-intensive crops during spring and summer
Learn more: The Seasonal Land Fallowing Program

Palo Verde Irrigation District 
Metropolitan pays farmers to fallow up to 35 percent of their land 
Learn more: Land Fallowing & Crop Rotation Program

The Quechan Tribe 
Metropolitan and the Quechan Tribe have launched a two-year pilot program to conserve Colorado River water while supporting the Tribe's agricultural economy. Metropolitan also has a forbearance agreement with the Quechan, through which Metropolitan pays the tribe to not grow crops on certain undeveloped land
Learn more: An Urban-Agriculture Partnership with The Quechan Tribe

Imperial Irrigation District 
Metropolitan funds water conservation improvements within IID 

Reducing Reliance: Urban Water Savings  

Metropolitan has also worked for decades to reduce its reliance on the river by lowering urban demands. Together with our partners across Southern California, we’ve invested billions of dollars in projects and programs to lower consumer demands and develop more supplies.

Thanks to these investments, average per person water use in the region has dropped more than 45% over the last 30 years. Some of those savings have provided direct benefits to Lake Mead, significantly increasing its elevation.

Metropolitan continues to make significant investments in urban water efficiency, including by providing cash incentives to homes and businesses that install water-saving devices and landscapes.

$7/square-foot: 
Beginning in September 2025, the cash incentive Metropolitan provides non-residential properties that replace their grass with California Friendly® and native landscapes, with funding from Reclamation’s Lower Colorado River Basin System Conservation and Efficiency Program and the California Department of Water Resources.

 

Partnerships Across the Basin:

Metropolitan has also worked with partners across the Colorado River Basin to ensure the river’s reliability in recent decades. 

Shortage Sharing

Shortage Sharing

In 2007, in response to a sharp drop in reservoir storage, the Basin states negotiated the Interim Shortage Guidelines for operation of lakes Powell and Mead through 2026. Among other rules, the Interim Shortage Guidelines defined three levels at which Lake Mead would be declared in shortage and established guidelines on how Colorado River supplies would be cut back for the Lower Basin states at each of those shortage levels.

Lake Mead

Intentionally Created Surplus

The Interim Guidelines also established Intentionally Created Surplus, a program that allows Metropolitan and other water agencies to store “surplus” water in Lake Mead. The program helps keep water levels in Lake Mead higher, while also providing valuable storage that water users can tap into. Metropolitan has taken full advantage of the program – we’ve stored 1.5 million acre-feet in Lake Mead, boosting the reservoir’s level by 20 feet, thanks to our investments in agricultural and urban conservation. View the ICS White Paper.

Drought Contingency Plan signing ceremony

Drought Contingency Plan

Signed in 2019, Metropolitan worked with the seven Basin states to develop the DCP, which furthered efforts to keep Lake Mead and Lake Powell from reaching critically low levels. Under  the DCP,  each Lower Basin state agreed to add defined volumes of water to Lake Mead at certain elevations, and the Upper Basin received approval to store conserved water in Lake Powell.

Signing

Tribal Nations

Metropolitan has collaborated with several Native American tribes in the Colorado River Basin to develop water management programs, including a forbearance agreement and seasonal fallowing program with the Quechan Tribe and an exchange agreement with the San Luis Rey Band of Mission Indians. 

Razorback Sucker

Lower Colorado River Multi-Species Conservation Programs

To balance the use of Colorado River resources with ecological needs, federal and state partners created the LCR MSCP in 2005 to work toward the recovery of endangered and threatened fish and wildlife along the Lower Colorado. The program is creating more than 8,100 acres of new habitat and provides 50 years of compliance for water and power operations in the Lower Basin. 

Invasive Quagga Mussels.

Lower Colorado River Water Quality Partnership

To protect the source water quality of Colorado River supplies, Metropolitan is partnering with the Central Arizona Project and Southern Nevada Water Authority on initiatives to address water quality challenges including salinity, invasive species and industrial contaminants.

Brock reservoir

Other Programs

Metropolitan has partnered with agencies in Nevada and Arizona to fund other projects important to protecting Colorado River supplies, including Warren Brock Reservoir, Yuma Desalting Plant and the Mexico Water Treaty Pilot Conservation Project (Minute 319 and 323).

Some photos courtesy of Bureau of Reclamation.