Mesa's Water Reliability and Preparedness

Overview

Mesa is prepared today for a reliable tomorrow

The U.S. Department of the Interior and Bureau of Reclamation have finalized a new 10-year framework for managing the Colorado River, including operating guidelines for 2027 and 2028 that significantly reduce Arizona’s Colorado River supply.

Mesa is prepared to maintain reliable water service through decades of planning, conservation, infrastructure investments and a diverse water portfolio. However, preparation does not eliminate the impacts of deeper or prolonged reductions. The City will continue evaluating its available supplies, hydrologic conditions and implementation of the federal decision while investing in conservation, reuse, infrastructure and additional water supplies to protect Mesa’s long-term water reliability.

Mayor Mark Freeman August 24 statement

What This Means for Mesa Residents and Businesses

The Colorado River is an important part of Mesa’s water supply, but it is one of the several water sources that support the community. Mesa’s long-term planning and investments have positioned Mesa to adapt to changing conditions while continuing to provide reliable water service.

Your water service remains reliable, and residents and businesses are encouraged to use water efficiently.

Mesa remains in a Stage 1 (Water Watch) of its Water Shortage Management Plan.

Mesa has planned for changing Colorado River conditions for decades.

City Staff are evaluating the new operating framework and will continue updating the public as needed.

Frequently Asked Questions

What did the federal government announce?

The U.S. Department of the Interior and Bureau of Reclamation finalized a new 10-year framework for managing the Colorado River, along with operating guidelines for 2027 and 2028.

The guidelines reduce Lower Basin apportionments by 1.25 million acre-feet annually in each of the next two years. If the necessary implementing agreements are executed, Arizona’s share will be 760,000 acre-feet each year, with additional reductions assigned to California and Nevada. Beyond these reductions, Lower Basin water users are expected to conserve at least 700,000 acre-feet cumulatively through voluntary agreements during the 2026–2028 implementation period.

Will my water service be affected?

No. Residents and businesses can continue to expect safe, reliable water service.

Mesa is prepared to maintain dependable water service through its diverse water portfolio, stored supplies, infrastructure and shortage planning.

However, preparation does not eliminate the impacts of reduced Colorado River supplies. Stored water is finite, and deeper or prolonged reductions will require continued investment, conservation, operational flexibility and development of additional water supplies.

How could this effect Mesa?

The new federal framework significantly reduces Arizona’s Colorado River supply and is expected to affect the amount of Colorado River water available to Mesa through the Central Arizona Project.

The precise impact to Mesa will depend on hydrologic and reservoir conditions and how the reductions are implemented in Arizona. City staff will evaluate these factors along with Mesa’s available supplies before recommending any additional actions.

Why is Mesa prepared?

Mesa has planned for Colorado River shortages and changing water conditions for decades. Mesa’s water portfolio and long-term strategy include:

Colorado River water

Salt and Verde River water

Groundwater

Reclaimed water exchanges

Water stored for times of shortage

Conservation and demand management

Continued infrastructure investments

These resources provide Mesa with options for managing reductions and maintaining reliable water service. However, deeper or prolonged reductions will require continued investment, greater flexibility and new water solutions to protect Mesa’s long-term water reliability.

Will there be new water-use restrictions?

The federal decision does not automatically impose new water-use restrictions in Mesa or trigger a change under the City’s Water Shortage Management Plan.

City staff will evaluate Mesa’s Colorado River allocation, hydrologic and reservoir conditions, available supplies, recovery capacity and overall system conditions before recommending any changes to the City Council.

Residents and businesses will be informed before any new measures are implemented.

What happens next?

Mesa will continue evaluating the federal decision, its implementation in Arizona, hydrologic conditions and the water supplies available to the City.

The City will carefully manage its available water while expanding conservation and reuse, strengthening infrastructure and pursuing additional water supplies. Mesa will also continue working with regional, Tribal, state and federal partners and advocating for an equitable, lasting Basin-wide solution.

Mesa’s preparedness provides time to respond and adapt, but continued action and investment will be necessary to protect the community’s long-term water reliability.

What should Mesa residents and businesses do now?

No emergency measures are needed at this time, but continued water conservation remains important as Colorado River supplies decline.

Residents and businesses are encouraged to use water efficiently and take advantage of Mesa’s conservation programs, rebates and other water-saving resources. The City will clearly communicate with the community if additional actions become necessary.

Where can I learn more?

Federal Information

The Bureau of Reclamation’s Post-2026 Colorado River Operations

Mesa's Water Sources

Mesa's reliable water system is built on a diverse portfolio of water supplies. Rather than relying on a single source, the City uses a combination of Colorado River water, Salt and Verde River water, and locally pumped groundwater to meet the community's water needs. This diversified approach helps strengthen water reliability during changing conditions.

Pie chart of where Mesa obtains water from

Mesa's Water Supply Portfolio

53% – Colorado River
Surface water delivered through the Central Arizona Project (CAP).
40% – Salt & Verde Rivers
Surface water supplied through the Salt and Verde River system.
7% – Groundwater
Locally pumped groundwater provides an important backup and supplemental water supply.

By maintaining a diverse water portfolio, Mesa is better positioned to adapt to changing water conditions while continuing to provide reliable water service.

Water Shortage Management Plan

Mesa's Water Shortage Management Plan provides a clear framework for responding to changing water supply conditions while maintaining reliable water service. The plan includes four stages, with conservation measures increasing as water supply conditions become more severe.

Water Shortage Stages

Stage One – Water Watch

Water service remains reliable.
Voluntary water-saving practices are recommended.
No mandatory water restrictions are in effect.

Stage Two – Water Alert

Additional conservation measures may be implemented.
Customers may be asked to increase voluntary conservation.
Mesa may take additional operational actions to reduce water demand.

Stage Three – Water Warning

Mandatory water-use restrictions may be implemented.
Additional conservation measures are required to reduce demand.
City operations are further adjusted to protect water supplies.

Stage Four – Water Emergency

Emergency water restrictions are implemented.
Water use is limited to protect essential public health and safety needs.
The City takes all necessary actions authorized under the Water Shortage Management Plan.

Current Water Shortage Stage
Mesa is currently in Stage One – Water Watch

This means:

Water service remains reliable.
Voluntary water-saving practices are recommended.
There are no mandatory water restrictions at this time.

Mesa continuously monitors water supply conditions and will notify residents and businesses well in advance if future actions become necessary.

What is Mesa doing?

Planning for the Future

Planning decades ahead: Mesa has proactively invested in water infrastructure, diversified water supplies, underground water storage, and demand management programs to prepare for changing water conditions.
Evaluating the new federal framework: City water experts are assessing the new Colorado River operating framework and its implications for Mesa's water supply and long-term planning.
Preparing for changing conditions: Mesa's comprehensive Water Shortage Management Plan provides a clear, staged approach for responding to changing water supply conditions while maintaining reliable service.
Exploring new water supplies: Mesa continues to evaluate sustainable and cost-effective water augmentation opportunities to strengthen future water reliability.

Protecting and Expanding Water Supplies

Banking water for the future: Mesa has stored more than 555,000 acre-feet of water underground to strengthen drought preparedness and water reliability. Stored water provides an important tool during shortages, but it is a finite resource.

Expanding water reuse: Mesa uses highly treated reclaimed water for beneficial uses and water exchanges, reducing demands on drinking water supplies. Through water exchange partnerships and the Central Mesa Reuse Pipeline, Mesa can secure additional surface water supplies while maximizing the value of its reclaimed water.

Strengthening infrastructure: Mesa continues investing in the infrastructure needed to manage its diverse water portfolio and provide greater flexibility as water supply conditions change.

Using Water Wisely

Leading by example: Through the City’s Leading by Example initiative, Mesa is reducing water use across municipal operations by optimizing landscape irrigation, improving efficiency in City facilities, expanding leak detection and water auditing, using innovative technologies to reduce water loss and empowering employees to identify water-saving opportunities.

Reducing water loss: Through industry best practices, advanced water auditing and proactive pipe inspection and replacement, Mesa maintains system water loss below 6%, well below state and national averages.

Encouraging efficient water use: A four-tiered water rate structure and drought commodity charge encourage conservation while supporting reliable water service.

Helping customers conserve: Mesa continues to offer conservation programs, educational resources and financial incentives for all types of water users.

Supporting Responsible Growth

Planning for new development: Mesa evaluates projected water demands from qualifying developments through its sustainable water-use policies. Some projects may be required to secure additional water supplies to offset their demand rather than relying solely on the City’s existing water portfolio.

Integrating water and growth planning: Mesa’s Water Master Plan guides long-term infrastructure investments and helps coordinate water planning with future development and available water supplies.

Advocating for Arizona's Water Future

Advocating for a fair Basin-wide solution: Mesa will continue advocating for an equitable and lasting solution where every state and sector that depends on the Colorado River contributes meaningfully to protecting the river and its long-term sustainability.

Working with regional partners: Mesa works with neighboring communities, water agencies, Tribes, and state and federal partners to protect municipal water supplies and Arizona’s long-term water future.

Advocating for continued investment: Mesa supports substantial, sustained state and federal investment in infrastructure, conservation, reuse and development of new water supplies so the costs of adapting to Colorado River reductions do not fall disproportionately on Arizona communities and local water customers.

Supporting regional conservation: Mesa participated in the historic 500+ Plan, contributing 1,300 acre-feet of water to help stabilize Lake Mead.

Keeping the community informed: Mesa will continue providing residents and businesses with timely updates as the federal decision is implemented and will clearly communicate if additional actions become necessary.

One acre-foot of water is 325,851 gallons. This is enough water to cover one acre of land with one foot of water. Based on Mesa’s median household water use, one acre-foot can serve about four to five households for one year.

What can you do?

Every resident and business plays an important role in protecting Mesa's water future. While the City continues to invest in infrastructure, conservation, and long-term water planning, the everyday choices we make at home and at work also matter. Most household water use occurs outdoors, making landscape irrigation one of the greatest opportunities to save water.

You can help by:

Watering wisely by adjusting irrigation schedules for the season and weather conditions.

Fixing leaks promptly, including dripping faucets, running toilets, irrigation systems and sprinkler heads.

Upgrading to water-efficient fixtures and irrigation equipment to reduce indoor and outdoor water use.

Choosing desert-adapted plants that thrive in Arizona’s climate while requiring less water.

Avoiding unnecessary outdoor watering, especially during or after rainfall.

Exploring Mesa’s conservation programs and resources to find ways to use water more efficiently and reduce water costs.

Visit Save Water Indoors and Out to find water-saving tips, irrigation guidance, conservation resources, and information on programs that can help you save both water and money.

Maximizing Operational Efficiency

We build and maintain one of the largest water pipe infrastructure systems in Arizona. Water loss control in the distribution system is key to a sustainable water supply. We maintain less than 6% water loss from main breaks and leaks, well below state and national averages, due to a rigorous pipe inspection and replacement program. The latest technologies are used to detect leaks before they happen so repairs can be made and old pipe replaced.

We also conduct water loss audits to identify, document, evaluate and address water losses using industry-recognized and best management practices of the American Water Works Association's M36 methodology.

Demand Management

We promote and encourage voluntary water conservation. Municipal water efficiency is at the top of the list when managing water demands. Mesa ensures all facilities use water as efficiently as possible in their business functions.

It doesn't help to have adequate water supply if the water can't be treated. Maintaining water treatment capacity needed to meet customer demand is an essential part of water stewardship. Mesa treats water at three state-of-the-art water treatment plants including the new Signal Butte Water Treatment Plant. Learn more about our water treatment and processes.

In 2019, the Mesa City Council approved the Large Customer Sustainable Water Allowance ordinance to manage large commercial/industrial water users. The ordinance requires these customers to stay within a water budget and in some cases, they must bring their own water to the table – meaning they must acquire long-term storage credits on their own that they turn over to Mesa. These credits are used over time to meet the high water demands of their business operations. This ordinance protects Mesa's water supplies from being compromised, while balancing economic development opportunity.

Wastewater Infrastructure and Reuse

Mesa professionals are experts at getting their hands on more water in creative ways. Part of this strategy includes infrastructure investments - thanks to Mesa residents who approve bonds.

What does a water reclamation plant have to do with drinking water supplies?

Treated wastewater (effluent) from the plant is sent to the Gila River Indian Community for crop irrigation in exchange for vital Colorado River supplies. The exchange is a ratio of one acre-foot of Mesa reclaimed water to .8 acre-foot of Colorado River water. It is a win, win exchange because irrigating with effluent is much cheaper than river water and Mesa can use the potable water supplies - also it is a beneficial reuse of effluent.

Another infrastructure investment to expand Mesa's water resources is the 10.5-mile Central Mesa Reuse Pipeline, which will deliver effluent produced at the Northwest Water Reclamation Plant as part of the water exchange agreement with the Gila River Indian Community. The pipeline helps Mesa meet the conditions of the exchange agreement by maximizing deliveries and gaining an additional 8,000 acre-feet of Colorado River water supplies.

Recharge (putting water back into the aquifer) is another way that Mesa increases its water supply through long-term storage credits. Class A+ effluent is locally recharged to the Granite Reef Underground Storage Project. On average, Mesa recharges about 8,000 acre-feet of water a year. That is about 5.4 million gallons a day! All that water is stored underground (banked) for recovery later when needed most. Mesa has over 540,000 acre-feet of water stored in the aquifer. Long-term storage credits are an important component to shortage and long-term resilience planning.

Learn more about beneficial reuse in the wastewater treatment, reclamation and recharge process.