Charles V. Stern and Pervaze A. Sheikh have updated (6 April 2022) this important CRS report on my favorite river: Management of the Colorado River - Water Allocations, Drought, and the Federal Role'.
Download CRS_Report_Mgmt_CO_River_Fed_Role_6April2022
Here is an updated map of the Colorado River Basin from the Lincoln Institute:
Download Crb_map_web

Summary
The Colorado River Basin covers more than 246,000 square miles in seven U.S. states (Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada, and California) and Mexico. Pursuant to federal law, the Bureau of Reclamation (part of the Department of the Interior) manages much of the basin’s water supplies. Colorado River water is used primarily for agricultural irrigation and municipal and industrial (M&I) uses; it is also important for hydropower production, fish and wildlife, and recreational uses.
Apportioned Colorado River water is widely acknowledged to be in excess of the river’s natural flows, and consumptive use of these waters typically exceeds natural flows. This causes an imbalance in the basin’s available water supply and demand. Stress on basin water supplies is exacerbated by a long-term drought dating to 2000.
River Management
Multiple laws, court decisions, and other documents govern Colorado River operations; its foundational document is the Colorado River Compact of 1922. Pursuant to the compact, the basin states established a framework to apportion water supplies between the river’s Upper and Lower Basins, with the dividing line between the two basins at Lee Ferry, AZ. Each basin was allocated 7.5 million acre-feet (MAF) annually under the compact, and an additional 1.5 MAF in annual flows was made available to Mexico under a 1944 treaty. Further agreements and court decisions addressed other issues, and subsequent federal legislation provided authority and funding for federal facilities that allowed users to develop their allocations. A 1963 Supreme Court ruling confirmed that Congress designated the Secretary of the Interior as the water master for the Lower Basin, a role in which the federal government manages the delivery of all water below Hoover Dam.

Reclamation and basin stakeholders closely track the status of two large reservoirs—Lake Powell in the Upper Basin and Lake Mead in the Lower Basin—as an indicator of basin storage conditions. Under criteria agreed upon by basin states, water releases from both lakes are tied to specific water storage levels. In recent years, storage levels have been falling. On August 16, 2021, Reclamation declared the first-ever Level One Shortage Condition in the Lower Basin, which reduced water deliveries to contractors in Arizona and Nevada, as well as to Mexico. For its part, in 2022, Lake Powell’s surface water elevation fell below a key target (3,525 feet) established to protect hydropower infrastructure at Glen Canyon Dam. In response, Reclamation has implemented drought response operations intended to protect Lake Powell elevations.
Efforts to Address Drought
The federal government has led multiple efforts attempting to improve the basin’s water supply outlook, resulting in collaborative agreements in 2003 and 2007, and most recently in the 2019 drought contingency plans (DCPs) for the Upper and Lower Colorado River Basins. The latter agreements were authorized by Congress in the Colorado River Drought Contingency Plan Authorization Act (P.L. 116-14). The DCPs required reductions beyond previous curtailment plans based on Lake Mead storage levels, committed Reclamation to additional water conservation efforts, and put in place plans to coordinate Upper Basin operations to enhance Lake Powell storage levels and prevent the loss of hydropower generation.
The basin’s hydrologic outlook has further deteriorated since passage of the DCPs, and there remains widespread concern about the basin’s long-term water supply. Should the current drought continue, some see the potential for drastically reduced deliveries to some contractors, and/or a compact call (i.e., a call on water rights between the Lower and Upper Basins). A central question facing decisionmakers is whether to renew interim agreements (including the DCPs) prior to their expiration in 2026, along with what (if any) additional changes might be necessary to prevent future shortages.
Congressional Role
Congress plays a multifaceted role in federal management of the Colorado River Basin. Congress funds and oversees management of basin facilities and has held oversight hearings on drought in the basin and elsewhere. Congress also has enacted legislation involving allocation of Colorado River waters (e.g., authorization of Indian water rights settlements; new water storage facilities) and authorities to mitigate water shortages (i.e., the DCPs and other related efforts). In the future, Congress may be asked to amend or extend these authorities to combat long-term water shortages.
Skipping to the end..
500+ Plan
The Lower Basin DCP included a provision that if Reclamation’s modeling (which includes all of the aforementioned conservation efforts) indicates a possibility of Lake Mead reaching an elevation at or below 1,030 feet, the Secretary of the Interior and the Lower Basin states would consult on additional measures to avoid and protect Lake Mead declining below 1,020 feet. This provision was triggered in Reclamation’s August 2021 24-month study, which projected the possibility for such a scenario by 2023 under its “Probable Minimum Inflow” scenario. In response, Lower Basin parties and the DOI met and in December 2021 agreed on a new set of actions in a memorandum of understanding, known as the 500+ Plan. This plan calls for contributions of up to $100 million by Lower Basin users ($40 million from the Arizona Department of Water Resources and $20 million each from the Central Arizona Water Conservation District, the Metropolitan Water District of Southern California, and the Southern Nevada Water Authority), plus another $100 million from the federal government, which collectively will result in the conservation of an additional 500,000 AF in Lake Mead in each of 2022 and 2023 (i.e., 1 MAF). Federal funding for these conservation efforts was made available through a combination of discretionary appropriations to Reclamation, as well as supplemental funding in the Infrastructure Improvement and Jobs Act (P.L. 117-58).

Issues for Congress
Funding and Oversight of Existing Facilities and Programs
The principal role of Congress as it relates to storage facilities on the Colorado River is funding and oversight of facility operations, construction, and programs to protect and restore endangered species (e.g., Glen Canyon Dam Adaptive Management Program and the Upper Colorado River Endangered Fish Program). In the Upper Basin, Colorado River facilities include the 17 active participating units in the Colorado River Storage Projects, as well as the Navajo-Gallup Water Supply Project. In the Lower Basin, major facilities include the Salt River Project and Theodore Roosevelt Dam, Hoover Dam and All-American Canal, Yuma and Gila Projects, Parker-Davis Project, Central Arizona Project, and Robert B. Griffith Project (now Southern Nevada Water System).
Congressional appropriations in support of Colorado River projects and programs typically account for a portion of overall project budgets. For example, for the most recent year available (FY2018), the Lower Colorado Region’s operating budget was $559.5 million; $134.8 million of this total was provided by discretionary appropriations, and the remainder of funding came from power revenues (which are made available without further appropriation) and nonfederal partners.103 In recent years, Congress has also authorized and appropriated funding that has targeted the Colorado River Basin in general (e.g., the Pilot System Conservation Plan). Congress may choose to extend or amend these and other authorities specific to the basin.
While discretionary appropriations for the Colorado River are of regular interest to Congress, Congress may also be asked to weigh in on Colorado River funding that is not subject to regular appropriations. For instance, in the coming years, the Lower Colorado River Basin Development Fund is projected to face a decrease in revenues104 and may thus have less funding available for congressionally established funding priorities for the Development Fund.
Tribal Water Rights Settlements and Leasing
Most tribal water rights are senior to other users and thus are likely to play an important role in the future of the Colorado River. As discussed, Congress has approved Indian water rights settlements associated with more than 2 MAF of tribal diversion rights on the Colorado River; a portion of this water has been developed to date. Congress may be asked to consider new settlements that would add to this total. At the same time, Congress may be asked to expand certain tribes’ ability to market their water rights to other basin water users. For instance, in the 117th Congress, S. 3308 would authorize the Colorado River Indian Tribes (CRIT) to enter into agreements to lease a portion of their Colorado River water rights. Currently, some tribes have the ability to lease their water, whereas others (such as CRIT) do not.
Plans for New and Augmented Water Storage, Conveyance
Some states in the Upper Basin have indicated their intent to further develop their Colorado River water entitlements. For example, in the 115th Congress, Section 4310 of America’s Water Infrastructure Act (P.L. 115-270) authorized the Secretary of the Interior to enter into an agreement with the State of Wyoming whereby the state would fund a project to add erosion control to Fontenelle Reservoir in the Upper Basin. The project would allow the state to potentially utilize an additional 80,000 acre-feet of water storage on the Green River, a tributary of the Colorado River.
Another project that would develop Upper Basin waters is the proposed Lake Powell Pipeline (LPP), which would direct approximately 86,000 acre-feet of Utah’s Upper Basin Colorado River Basin apportionment from Lake Powell to Washington County, UT (i.e., the St. George, UT, area, which is technically located within the Lower Basin drainage area). The pipeline would begin near Glen Canyon Dam in Arizona and would run through Arizona and Utah to Sand Hollow Reservoir near St. George, UT. Reclamation has been designated the lead agency for the project under NEPA and is coordinating an Environmental Impact Statement (EIS) for the most recently proposed version of the project. Supporters in Utah argue that the pipeline is needed to provide a second primary water source for the St. George area, in addition to the Virgin River. Some environmental groups have argued that the proposed development and diversion of additional Upper Basin waters is ill-advised in light of climate change and the basin’s issues with over-allocation. These groups have argued for major changes to the scope of the EIS. The six other Colorado River Basin states have raised concerns related to the proposed LPP’s “legal and operational issues,” and they have raised concerns with the LPP NEPA process as the de facto forum for resolving a conflict among basin states. The six states previously requested that Reclamation refrain from issuing a final EIS until these issues can be resolved on a consensus basis.
Drought Contingency Plan Implementation and Future Basin Agreements
Congress is likely to remain interested in the status of long-term drought in the basin and in the implementation of the DCPs and other related agreements, including their ability to stem further delivery curtailments and add water to the basin’s storage reservoirs. Congress also may be interested in broader basin planning, including new and existing efforts to plan for increased demand in the basin and stretch limited basin water supplies.
Federally led efforts to extend the 2007 Interim Guidelines (including the DCPs), which expire at the end of 2026, look to be the next major set of negotiations in the consensus-based management of the Colorado River. These “reconsultation” efforts, including any major changes to existing agreements, are seen as key to managing the basin’s future water resources. At the same time, new agreements that would protect water supplies in the short-term, such as the 500+ Plan, an Upper Basin Demand Management Program, and DROA Drought Plans, could themselves result in additional congressional involvement in funding, oversight, and/or enactment of new authorities.
Enjoy!
"I love when faculty complain on Twitter about rejections from journals. It’s so informative. Y’all are telling on yourselves and don’t even know it. We’ve adjusted your merit raises accordingly!" - @ass_deans
Recent Comments