ARIZONA

River Stakeholders

Colorado River Water Use Highlights:

Arizona Colorado River Water Use:

From the 2024 Annual Report – View Full Report Here ⟶

Arizona Governor’s water leadership

In May 2023, Arizona Gov. Katie Hobbs, along with the state’s water leaders, outlined Arizona’s support for a NEPA alternative in the Draft Supplemental Environmental Impact Statement (SEIS). The alternative involves participation in a Lower Basin Colorado River water proposal that the governor observed would help protect the state’s water future and “puts the state on the right path to conserve water in the long-term.”

The proposal as outlined by the Arizona governor on May 25 and presented to the Department of the Interior by Arizona, California and Nevada is for the Lower Basin to conserve three million acre-feet in the Colorado River system, a substantial portion of which will be conserved by Arizona’s water users. All of the proposed contributions by Arizona water users are voluntary.

At the same time, she observed that the work of her newly empaneled state Water Policy Council, which is focused on both conservation and augmentation efforts, “complements” the proposal to conserve Colorado River water.

The Lower Basin proposal, she said, “is a critical first step in securing our state’s water future for generations to come,” noting that it will boost the ability of the Colorado River states to focus on system operation guidelines post-2026.

Arizona users are conserving nearly 345,000 acre-feet of water in 2023 through the Central Arizona Water Conservation District (CAWCD)/ Arizona Department of Water Resources (ADWR) Intentionally Created Surplus (ICS) Preservation program as well as federally funded Central Arizona Project (CAP) subcontractor, tribal contractor and on-river conservation agreements. This is in addition to the 592,000 acre-foot mandatory Tier 2a shortage reduction taken by Arizona.

Arizona Reconsultation Committee work continues

The Arizona Reconsultation Committee (ARC), meanwhile, is continuing its work preparing input to Arizona’s negotiating team on the reconsultation of 2007 guidelines using hydrologic information provided and vetted by a subcommittee referred to as the Modeling & Analysis Work Group

Water Infrastructure Finance Authority

Also, as a complement to Colorado River conservation efforts, Arizona has directed considerable new resources to its Water Infrastructure Finance Authority. WIFA is an independent state authority authorized to finance the construction, rehabilitation, acquisition, and improvement of water infrastructure throughout Arizona.

CENTRAL ARIZONA PROJECT

Beginning 2023 in Tier 2a shortage

Arizona began 2023 in the first-ever declared Tier 2a shortage for Colorado River operations. This represented a 592,000 acre-foot reduction to Arizona’s Colorado River supply, constituting 34% of Central Arizona Project’s normal supply in an average year, 21% of Arizona’s Colorado River supply and about 9% of Arizona’s total water use.

Nearly all the reductions within Arizona have been taken by Central Arizona Project (CAP) water users. These reductions are implemented pursuant to the CAP priority system – the result being no Colorado River water available for the Excess Water or Agricultural pools and a slight reduction to Municipal & Industrial (M&I) and Tribal supplies.

Joint communications efforts are ongoing and representatives from the Arizona Department of Water Resources (ADWR) and CAP continue to field media calls from local, regional, national – and even international – media outlets. Communications efforts regarding shortage have included a fact sheet, FAQ, stakeholder briefings, infographics and community presentations.

Three-state consensus proposal

In May, CAP – along with ADWR – announced a consensus proposal developed by Arizona, California and Nevada to conserve historic volumes of Colorado River water in Lake Mead. The proposal reflects commitments to conserve three million acre-feet in Lake Mead over the next three years, the first 1.5 million of which would “front-load” by the end of 2024.

With this proposal in hand, the Department of the Interior announced it was temporarily withdrawing its draft Supplemental Environmental Impact Statement (SEIS) so that it can fully analyze the effects of the proposal under the National Environmental Policy Act (NEPA). A decision is expected in fall 2023.

Return to Tier 1 shortage for 2024

This year’s favorable hydrology is leading to the return of a Tier 1 shortage for 2024, which equates to a 512,000 mandatory acre-foot reduction to Arizona’s Colorado River supply. This constitutes about 30% of CAP’s normal supply and about 18% of Arizona’s Colorado River supply.

ON-RIVER

Yuma-area growers rely on Colorado River water to grow America’s winter leafy greens and a wide variety of other valuable agricultural products.

In recent decades, Yuma-area agriculture has steadily increased its productive output, doubling crop yields in some cases and increasing the economic value of the area by 700%. Over the same period, its water use markedly decreased, by an average of 15% since 1990 (0.8 acre-foot/acre) and nearly 18% since 1975 (1.0 acre-foot/acre). This decrease is attributable to a variety of factors, including shifts in cropping patterns but especially the implementation of numerous irrigation efficiency practices that leave tens of thousands of acre-feet of water in the Colorado River every year.

Challenges have included increased salinity of Colorado River water and a transition to a more consolidated food industry. In addition, due to decreased power generation at Glen Canyon and Parker dams, the firm electric service price charged by Western Arizona Power Association (WAPA) has increased substantially due to the need to purchase firming power. The overall price of purchased power has increased, as well.

SALT RIVER PROJECT

For more than 120 years, Salt River Project (SRP) has managed a robust system of dams, reservoirs and canals to deliver reliable water to more than 2.5 million residents in the Phoenix metropolitan area. As Arizona continues to thrive in the midst of a record drought, SRP continues to look for innovative ways to maintain our water resiliency legacy.

SRP has been working collaboratively with local stakeholders from the tribal, agricultural and municipal and industrial sectors to improve operational systems while researching proposed water augmentation projects that will improve the resiliency of the water supply in central Arizona.

A feasibility study is currently underway by the Bureau of Reclamation (Reclamation), SRP, and 22 non-federal partners on a proposal to modify Bartlett Dam on the Verde River by raising the existing dam about 100 feet. This would restore storage capacity lost to sedimentation, improve sediment management, and expand total water storage for capturing flood waters.

The proposed project would increase conservation storage capacity on the Verde River by about 350,000 acre-feet – enough water to support about 1.1 million households in the Phoenix metropolitan area for a year. The additional stored water could also be made available for use outside of SRP’s water service area to support water users in central Arizona.

In addition, SRP, the Army Corps of Engineers, Reclamation and 14 partners from the tribal, agricultural and municipal and industrial water sectors are proposing a five-year project to temporarily modify the operating rules in the flood control space (FCS) at Theodore Roosevelt Dam on the Salt River. If approved by the Corps, the project would extend the evacuation period of the FCS from 20 days to 120 days for 110,000 acre-feet of the FCS, improving the ability to put flood waters of the Salt River to beneficial use inside and outside of SRP’s water service area. If fully utilized during a flood event, that amount could support about 330,000 Phoenix area households for a year.

Arizona’s Salt & Verde River System - Water Year 2022

Last winter, Arizona and much of the Southwest experienced record snowfall that led to a productive runoff season for its reservoirs. SRP snow surveys determined that snowpack on the 13,000-square-mile watershed that replenishes the Salt and Verde River reservoirs was the deepest it had been in 30 years.

SRP ended the 2023 winter run-off season with total inflow from the Salt and Verde rivers of about 1.8 million acre- feet. That is about 400% of combined median run-off. The productive winter has resulted in the Salt-Verde system at 88% full today compared to 65% a year ago That is about 400% of combined median run-off compared to the 2022 run-off season of 217,000 acre-feet, one of the driest on record.

Throughout the year, SRP strategically releases water from the dams on the Salt and Verde rivers into a series of canals to meet the water needs of the 2.5 million residents in the Phoenix metropolitan area. In particularly wet winters, like 2023, when the reservoirs are nearing capacity, releases outside of the canal system are required to make room in the reservoirs for additional expected runoff. 2023 inflows exceeded the reservoir storage capacity on the Salt and Verde rivers necessitating releases into the Salt River bed. The record-breaking winter precipitation and runoff prompted SRP to release about 732,000 acre-feet downstream of our reservoirs in order to ensure safety of dams. SRP ended the runoff season at full capacity at all seven of the dams it manages.

Another source of inflows for the Salt and Verde River watersheds is monsoon moisture. In some years, monsoon rains bring enough additional water to make up for dry winters, which is what happened in 2022. Unlike the 2022 monsoon season, which produced above normal precipitation across the SRP watersheds, the 2023 monsoon season ended up being one of the driest on record, exemplifying the unpredictable nature of weather and water supplies. While the productive winter provided SRP with full reservoirs, the utility has remained committed to managing for drought and educating customers on the importance of conserving in this dry, arid environment.

Arizona started 2020 operating for the first time under the Drought Contingency Plan’s (DCP) Tier Zero. This reduced Arizona’s Colorado River supplies by 192,000 acre-feet. By agreement, Central Arizona Project (CAP) took this entire reduction, representing 12% of its normal annual Colorado River water supply. For CAP customers, this eliminated water that would have been available for underground storage, banking and replenishment. Water for CAP agricultural uses was reduced by about 15%.

The Tier Zero reduction to CAP, while significant, was largely equivalent to the amount of Colorado River water CAP had been leaving voluntarily in Lake Mead since 2015 as part of its Lake Mead Conservation Program. In essence, CAP and its water users planned and prepared for Tier Zero reductions for the past five years. Those previous contributions were voluntary – now, under DCP, these contributions are mandatory.

Based on the U.S. Bureau of Reclamation’s (BOR) August 24-Month Study, it appears Arizona will continue in Tier Zero through 2021. With DCP a success, Arizona now will turn its attention to the future. The current 2007 Guidelines, along with the DCP overlay, will expire on Dec. 31, 2025. The U.S. Secretary of the Interior will be developing new guidelines for the long-term management of the Colorado River system. This process will take many years and require multiple levels of discussion, negotiation and coordination within Arizona and the Basin states.

To ensure Arizona remains stronger together, the Arizona Department of Water Resources and CAP have reconvened the Lower Basin Drought Contingency Plan Steering Committee delegates to form the Arizona Reconsultation Committee (ARC). The ARC Committee is tasked with developing an Arizona perspective on the reconsultation of 2007 Guidelines. Its members represent Arizona’s diverse water interests, including elected leaders, tribes, cities, farms, industry and environmental groups.

The challenges all Colorado River water users across the basin face as we enter these negotiations are serious: drought, over-allocation, growing water needs and the prospect of a drier future. Arizona will use the strength of its diverse water users and stakeholders, through the ARC process, to guide and inform an approach to addressing these challenges in the reconsultation negotiations.

At the same time, within Arizona the water year 2020 started with a wet November and December (125% to 200% of normal snowpack), and ended the winter season with the 12th wettest March on record. The end result was a total inflow of 150% of median for the winter runoff season (January through May). Roosevelt Lake increased from 66% to 99% full, nearly reaching capacity in April. On the Verde River system, reservoirs were at capacity by mid-March spilling approximately 30,000 acre-feet of water over Granite Reef Dam during the month.

The 2020 monsoon season ended up being the driest ever recorded over the Salt River Project’s (SRP) 121 year period of record. At just 30% of normal, an overall average of only 1.93 inches of precipitation was recorded across the watersheds. However, because of the wet winter, the reservoir levels are in good shape with total storage at 80% as of Sept. 1, compared to 70% at the same time last year. Total projected inflow for water year 2020 is approximately 1,058,000 acre- feet (116% of median). Climate predictions for the upcoming winter indicate a shift toward a weak La Nina indicating that the upcoming winter has a greater chance of drier conditions.

SRP is sponsoring an Appraisal Study that is being led by the Bureau of Reclamation to evaluate options to mitigate the nearly one-third of storage capacity loss due to natural sedimentation accumulation at Horseshoe Reservoir on the Verde River. The Verde Reservoirs Sediment Mitigation Study has incorporated a diverse group of stakeholders to help find a solution to a problem, that if left unchecked, will continue to diminish SRP and the City of Phoenix carry-over storage capacity in the reservoir. The loss of capacity is reaching a critical mass at a time when the Phoenix Metropolitan Area needs these water supplies more than ever in light of anticipated hydrologic impacts of climate change and potential shortage conditions on the Colorado River. The appraisal study is expected to be complete in 2021 and contribute to an action plan to restore the lost capacity.