State Water Project Table A Allocations 1967-1995

California Department of Water Resources (DWR) | January 14th, 2022

Statement from ADWR Director Tom Buschatzke and CAP General Manager Ted Cooke in response to the U.S. Department of the Interior announcement of actions to protect the Colorado River system and 2023 Operating Conditions for Lake Powell and Lake Mead

Arizona Department of Water Resources (ADWR) | August 16th, 2022

Statement of Camille Calimlim Touton, Commissioner, Bureau of Reclamation U.S. Department of the Interior Before the Senate Committee on Energy and Natural Resources June 14, 2022

Senate Committee on Energy and Natural Resources | June 14th, 2022

"The Colorado River Basin is in the 23rd year of a historic drought. Both Lake Powell and Lake Mead – the two largest reservoirs in the United States – are at histori

"The Colorado River Basin is in the 23rd year of a historic drought. Both Lake Powell and Lake Mead – the two largest reservoirs in the United States – are at historically low levels with a combined storage capacity of 28 percent of capacity. While Reclamation and its partners have been successful in conserving water in Lake Mead and Colorado River System reservoirs, more needs to be done as the system reaches critically low water levels. The system is at a tipping point. An example of how Tribal Nations and water managers have addressed these conditions is shown in how, over the past 15 years, approximately 4.6 million acre-feet (maf) have been conserved in Lake Mead through voluntary measures by the three Lower Basin States, Tribal Nations, and Mexico. This has been accomplished through the creation of Intentionally Created Surplus, system conservation water, water for Mexico’s water reserve under Minutes 318, 319, and 323, as well as other water conservation efforts. At current water levels, these measures add 70 feet to Lake Mead’s elevation and delayed the first shortage declaration by six years. Over the past few years, Reclamation has worked with the Upper and Lower Basin States, Tribes, and stakeholders on Colorado River Drought Contingency Plans (DCPs), which were implemented in 2019. The DCPs provide a framework for additional actions to help the basin adapt to drought. An example of this is a 2021 Lower Basin Memorandum of Understanding, called the 500 Plus Plan. The plan, developed under both the DCP and 2021 MOU, aims to conserve additional water above what is required under a Lower Basin shortage condition and contributions under the Lower Basin DCP. The 500 Plus Plan parties have identified and are funding projects in each of the three Lower Basin States, and the projects include tribal, agricultural, and municipal water users. On May 3, 2022, Reclamation announced two separate drought response actions that will help increase Lake Powell storage by nearly 1.0 maf over the next 12 months (May 2022 through April 2023). The two actions include: 1. Approximately 500,000 acre-feet of water will be released from Flaming Gorge Reservoir, located approximately 455 river miles upstream of Lake Powell, pursuant to an agreement as part of the Upper Basin Drought Contingency Plan (adopted in 2019); and 2. Another 480,000 acre-feet will be left in Lake Powell by reducing Glen Canyon Dam’s annual release volume from 7.48 maf to 7.00 maf, as outlined in the 2007 Interim Guidelines that control operations of Glen Canyon Dam and Hoover Dam. Regarding current conditions, in March 2022 Lake Powell dropped below elevation 3,525 feet, meaning the reservoir was less than 35 feet above the minimum power pool of 3,490 feet (i.e., minimum elevation at which hydropower can be generated). According to the May 2022 Most Probable 24-Month Study, the April-July runoff forecast into Lake Powell is 3.80 maf, or 59 percent of average. Lake Powell’s water surface elevation is projected to end the calendar year at 3,522.94 feet (22 percent full). Lake Mead is projected to reach an elevation of 1,039.92 feet (27 percent full) on December 31, 2022. While not official until the August 2022 24-Month Study, a shortage condition for the Lower Basin is projected in calendar year 2023. Looking to the future, Reclamation is preparing to develop new operating guidelines given that the 2007 Interim Guidelines expire in 2026. Reclamation is targeting initiating a formal National Environmental Policy Act (NEPA) process in early 2023. Technical information and lessons learned from management under the current guidelines will be very helpful as the basin strives to develop new guidelines that are durable and drought resilient. Additionally, collaboration and involvement by partners and stakeholders (Tribal Nations, States, water districts, etc.) will be paramount for the effort to be successful. Prior to the start of the formal NEPA process, Reclamation is preparing to issue a “pre-scoping” Federal Register notice (targeting the week of June 20) to ask for input on both the stakeholder engagement process and the substantive elements and strategies for post-2026 operations. Despite the actions taken by the Department and Reclamation, significant and additional conservation actions are required to protect the Colorado River system infrastructure and the long-term stability of the system."

Strategic Workplan for Activities in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary

California State Water Resources Control Board (SWRCB) | July 16th, 2008

The State Water Project Delivery Capability Report 2023 Addendum - Impacts of Subsidence

California Department of Water Resources (DWR) | May 7th, 2025

The purpose of this addendum is to show how ongoing subsidence effects on the California Aqueduct will impact operation of the State Water Project (SWP). The addendum pro

The purpose of this addendum is to show how ongoing subsidence effects on the California Aqueduct will impact operation of the State Water Project (SWP). The addendum provides information to SWP water users about a potential range of water delivery impacts over the next 20 years if no corrective action is taken to address the subsidence effects. However, the California Department of Water Resources (DWR) is committed to restore the conveyance capacity of the California Aqueduct and has an engineering plan for near-term fixes. DWR is also working with its partners to secure additional funding sources for this work. DWR is confident that the California Aqueduct capacity will be restored and the SWP will not see the impacts outlined in this addendum. Thus, long-term water supply planning activities by water users should rely on the potential future SWP allocation results presented in the 2023 Delivery Capability Report (DCR 2023) released in 2024.

The twenty-first century Colorado River hot drought and implications for the future

American Geophysical Union (AGU) | February 17th, 2017

Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906–1999 average, the worst 15-year drought on record. At least one-sixth to one-half (averag

Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906–1999 average, the worst 15-year drought on record. At least one-sixth to one-half (average at one-third) of this loss is due to unprecedented temperatures (0.9°C above the 1906–1999 average), confirming model-based analysis that continued warming will likely further reduce flows. Whereas it is virtually certain that warming will continue with additional emissions of greenhouse gases to the atmosphere, there has been no observed trend toward greater precipitation in the Colorado Basin, nor are climate models in agreement that there should be a trend. Moreover, there is a significant risk of decadal and multidecadal drought in the coming century, indicating that any increase in mean precipitation will likely be offset during periods of prolonged drought. Recently published estimates of Colorado River flow sensitivity to temperature combined with a large number of recent climate model-based temperature projections indicate that continued business-as-usual warming will drive temperature-induced declines in river flow, conservatively −20% by midcentury and −35% by end-century, with support for losses exceeding −30% at midcentury and −55% at end-century. Precipitation increases may moderate these declines somewhat, but to date no such increases are evident and there is no model agreement on future precipitation changes. These results, combined with the increasing likelihood of prolonged drought in the river basin, suggest that future climate change impacts on the Colorado River flows will be much more serious than currently assumed, especially if substantial reductions in greenhouse gas emissions do not occur.

Upper Colorado River Basin Compact, 1948

U.S. Bureau of Reclamation (USBR) | October 11th, 1948

Upper Division States Alternative for Post-2026 Operations of Lake Powell and Lake Mead

Colorado Department of Natural Resources (DNR) | March 5th, 2024

Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande: Treaty Between the United States of America and Mexico

U.S. Government Publishing Office (GPO) | November 14th, 1945

Water Allocation, Use, and Regulation in California

California Department of Water Resources (DWR) | October 30th, 2014

In California, water use and supplies are controlled and managed under an intricate system of common law principles, constitutional provisions, State and federal statutes

In California, water use and supplies are controlled and managed under an intricate system of common law principles, constitutional provisions, State and federal statutes, court decisions, and contracts or agreements. All of these components constitute the institutional framework for the protection of public interests and their balance with private claims in California’s water allocation and management.