SRP

How SRP's long-term water and power management are driving a sustainable future for Arizona.

Christa McJunkin

Senior Director of Water Supply and System

A New Way to Water

From Hohokam canals to pumped-storage hydropower, Arizona's water story has always been about ensuring the needs of today and tomorrow are met.

Christa McJunkin spends a lot of time sharing good news. That’s something people don’t typically expect from someone who talks about water in the Southwest.

As the Senior Director of Water Supply and System at Salt River Project (SRP), McJunkin oversees operations and maintenance at one of Arizona’s primary utility companies. Through the work of leaders like McJunkin, statewide commitments to conservation, and thoughtful urbanization, Arizona uses about the same amount of water today as it did in the 1950s, despite a much larger population and economic output.

That’s something people around the nation often miss due to the attention on the Colorado River, which supplies water to seven Western states but is in shortage in part due to a historic 25-year drought in the Southwest.

“Drought is a weather condition that we don't have any control over,” McJunkin said. “A shortage is what happens if you haven't planned properly.”

The good news for Arizona: State, local and tribal leaders have been planning for generations.

It’s not news to Arizonans that they live in a desert. Strategic, thoughtful management practices have consistently been key pillars for long-term planning.

The Hohokam people, who lived around Greater Phoenix from 300 B.C. to 1450 A.D., developed more than 500 miles of canal operated by gravity as large as 12 feet deep by 13 feet wide.

They knew that water was of the utmost importance in this environment.

When farmers came to the Salt River Valley in the 1860s, these canals served as the blueprint for updates and extensions. The National Reclamation Act, made it possible for these farmers to come together and put their land up as collateral for a loan to build Roosevelt Dam, creating a dependable water supply from a highly variable river system. The formation of SRP in the early 1900s to repay the loan, operate and maintain the water system, showed how, even pre-statehood, people understood: The area can only blossom when water is secure.

A History of Innovation

Water management developed adjacent to market growth in the mid-1900s behind the Central Arizona Project (CAP), generation stations and the Groundwater Management Act of 1980 (GMA). The population boomed following the advent of the air conditioner, and as hundreds of thousands of people moved in, Arizona legislators enacted laws to ensure that water would be protected.

Since then, water conservation has continued to develop alongside technological advances. Arizona has always been at the forefront of water stewardship And SRP is leading the way with strategic activity to ensure a resilient water supply.

“Water supply has been integral to the Valley's economic growth since our beginning,” McJunkin said. “What started as a dependable water supply for farmers turned into a water supply that supported the economic growth of the Valley as it urbanized. Being able to rely on a dependable water supply means that our businesses can have confidence that their investments in infrastructure and in building their businesses will be able to be sustained for decades.”

“Drought is a weather condition that we don't have any control over. A shortage is what happens if you haven't planned properly.”

Maximizing Water Resources

SRP, which manages 13,000 square miles of watershed on the Salt and Verde rivers, seven reservoirs, and an extensive system of wells, is central to many partnerships related to Arizona’s water.

“Our desert environment goes through wet and dry cycles,” McJunkin said. “The last two years have been two of the driest on record. In 2023, we saw a very wet winter that produced so much water that it filled up our reservoirs and required us to release water to maintain safety of dams.”

By releasing water, Arizona lost the opportunity to retain that water for drier seasons. SRP is leading a project to change that. SRP is undertaking feasibility studies to mitigate sedimentation like sand, gravel and other particles in Verde River reservoirs that crowds out water storage by potentially expanding Bartlett Dam to allow for additional water storage.

“If we'd had a larger Bartlett Reservoir in place in 2023, the water that we released from the Verde River system could have been captured and put to beneficial use,” McJunkin said.

The management of water ties closely to clean power generation and helps generate sustainable power for the company’s service area, consisting of about 2.5 million people.

SRP was one of the first utility companies in the Southwest to install pumped storage hydropower units in the early 1970s. While the company manages hundreds of megawatts of hydropower today, it is working on a new project on the Apache Lake, just south of Roosevelt Dam, that will produce up to 2,000 megawatts of long-duration, clean-energy storage, or enough to power between 225,000 and 450,000 homes for up to 10 hours during each discharge.

Pumped storage hydropower uses electricity to pump water upward to a higher reservoir when power demand is low, such as in the mornings or midday, or when there is a surplus of energy through solar or wind generation. When there is heightened demand, typically in the late afternoons and evenings, the process reverses: SRP uses gravity to rush water back down, passing through turbines, generating clean electricity to supplement the grid.

“It’s non-consumptive use,” said Joseph Gardner, a Power System Program Manager at SRP, who works on hydrostorage projects. “The water just keeps going back and forth, in a way that doesn’t disrupt how we manage and store water on the Salt River”

Diverse Energy Mix Helps Ensure Grid Reliability

This achieves multiple goals that help the region’s residents and businesses. Greater Phoenix, like much of the country, is experiencing record energy demand. Having added more than two gigawatts of clean, renewable energy in recent years, SRP is helping expand its energy mix to offer more power to people and companies, addressing the growing population, increased demand from large customers, and sustainable methods to combat rising temperatures.

The coordination between watershed and power management is a “dynamic” process, said Mary Faulk, the Director of Integrated System Planning (ISP). Launched in recognition that the power system is evolving into an increasingly dynamic system in 2020, the ISP gathers contributions from nine departments to plan for the future.

“We build on the principle value of a long-term plan for generations to come,” she said.

"Being able to rely on a dependable water supply means that our businesses can have confidence that their investments in infrastructure and in building their businesses will be able to be sustained for decades.”

SRP aims to store at least 1 million acre-feet of water underground by 2035 to support economic development with renewable water supplies. Additionally, Arizona is exploring desalination opportunities in partnership with users outside the state.

“It's a matter of when the technology will be right for Arizona to adopt at a large scale,” McJunkin said. “In the meantime, we have projects on the horizon in the 10- to 15-year range that will increase our water supply availability and increase our resilience to drought.”

The organization is building upon its decades of water and energy work while researching for what comes next. SRP commits $2.5 million annually to initiatives with Arizona State University, University of Arizona and Northern Arizona University that cover watershed research, forest health studies, home battery research and other optimizations. Chico Hunter, the Manager of Innovation and Development and an SRP employee of 20 years, said his team embraces the “big challenge” nature of this work.  

“I am an engineer. I love to solve problems,” he said. “If I am going to work hard on problems, I want them to be big and meaningful, and I think this is one of the most meaningful things I can do with my skills.”

For nearly the entirety of SRP’s history the utility has instituted conservation programs for residential users to make water usage more efficient. Likewise, SRP is growing its power system to diversify its generation and ensure reliable power service while maintaining affordable rates for customers. The goals are to maintain Arizona’s momentum in the southwest, in control of its own water and power destiny.