Glendale prepares for less CAP water

Sarah Porter

Bart Turner

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By Richard Smith
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X: @rsmithYWV

Glendale did not need its water resources update during the June 9 City Council workshop to know cuts to its water supply are inevitable and the alternative supplies the city built up may come into play.

Of the two main reservoirs along the Colorado River, where the city gets a good portion of its water, Lake Mead is at 30% capacity and Lake Powell is at 24% capacity, Water Resources Manager Zacary Richards said. The total Salt River Project reservoir system is at 54% capacity as of June 8. The system was at 67% a year ago.

“The Colorado River system is facing a historic hydrological dry period, with total system storage falling to 20 million acre-feet, a significant drop from the 23 million acre-feet recorded just one year ago.” Richards said.

Current guidelines for the Colorado River basin expire at the end of the year and an agreement is not close, he said. The federal government favors a new 10-year operational framework with new guidelines every two years.

A final federal decision is likely in July, with terms available by August.

The Salt and Verde rivers, which are controlled by SRP, account for 55% of the city’s drinking water supply, while the Colorado River handles 41% and groundwater chips in 4%. That is good news.

Councilmember Bart Turner said the area of Glendale north of Arizona Canal primarily receives Central Arizona Project-delivered drinking water from the Colorado River, while south of the canal is mostly SRP.

“Other cities in the metro area, many of them are heavily reliant on CAP water and they’re not in nearly as fortunate of a situation as the city of Glendale,” said Turner, a member of the Arizona Municipal Water Users Association board.

Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University, said she does not like to compare cities as more or less fortunate. There are many variables in a city’s ability to manage very deep cuts to water.

But cities that use CAP water to meet demand for tap water and watering turf facilities will experience the most immediate impacts if there are deep cuts. And some cities are set up better than others.

“Yes, cities that rely entirely on groundwater and Tempe, which relies on SRP and groundwater, won’t be impacted by cuts to the same extent as cities that rely on CAP supplies. In contrast, Scottsdale arguably relies more heavily on CAP supplies than Glendale and some other cities,” Porter stated in an email.

Valley water resources by the numbers

Porter breaks down the water resource position several Valley cities are in this summer:

• About half of the approximately 42,000 acre-feet of water Glendale sends to surface water treatment plants is from CAP and slightly less than half is from SRP. None of the water Glendale delivers to turf facilities — golf courses, cemeteries and parks — is CAP water. Also, Glendale’s main source of supply for aquifer recharge is effluent. But Glendale uses only about 14% as much water to recharge aquifers as it delivers to taps. Glendale has about 188,000 acre-feet of long-term storage credits.
• Peoria delivers about 32,500 acre-feet of tap water, 33% CAP water, 29% SRP and 39% groundwater. About half the water Peoria delivers to turf facilities is SRP water, 23% is groundwater, 15% is effluent and 13% is CAP water. In some years, Peoria uses almost as much water to recharge aquifers as it delivers to taps but two-thirds of the water it uses for recharge is CAP water. Peoria has 196,000 acre-feet of long-term storage credits.
• Scottsdale relies on CAP water for 71% of the approximately 82,000 acre-feet it uses to meet tap water demand with the rest divided almost equally between groundwater and SRP supplies. Approximately 33% of the water Scottsdale delivers to its turf facilities is CAP water. And about 70% of the water Scottsdale uses for aquifer recharge is Colorado River water. Scottsdale delivers about 20% as much water for aquifer recharge as it does to taps. Scottsdale has 247,000 acre-feet of long-term storage credits.
• Tempe, which uses close to the same amount of water as Glendale, doesn’t use any CAP water for tap water or for turf facilities. It has a modest CAP allocation that it historically has used for accruing groundwater credits (aquifer recharge) through an exchange. Historically, Tempe recharges about 10% as much water as it delivers to taps. Tempe has 78,000 acre-feet of long-term storage credits.

City prepares options to counteract cutbacks

This year’s March heat wave caused the snow pack to melt prematurely, wiping out most of the source of spring runoff.

The Bureau of Reclamation is reducing releases from Lake Powell to Lake Mead, which should translate to a 20% reduction in Glendale’s CAP water delivery in 2027. This will also reduce the Hoover Dam’s hydroelectric generating capacity by as much as 40%.

“The Bureau of Reclamation recently released a draft environmental impact statement outlining five federal strategies for managing Lake Powell and Lake Mead after 2026. These proposals have exposed a significant divide between the upper and lower basins with serious implications for the Central Arizona Project,” Richards said.

Instead of the current federal options, the city is pushing for a management framework based on actual river hydrology and river storage.

Glendale will update its drought management plan this year.

Likely reductions on the delivery of Colorado River water will take effect in 2027.

“Should Glendale’s allocation be reduced by 25% in any given year, we would still be able to meet all project demands with our CAP supply. However, if a 50% reduction should occur, we would need to begin pulling from our alternative supplies such as new conservation space, long-term storage credits that can feasibly be recovered and pumped groundwater,” Richards said.

He said 35% of the city’s recharged water is used to recharge Glendale’s aquifer. Annual water demand remains well below Glendale’s supply.

Five strategic well projects are designed to provide a backup for residents in higher elevation areas. One well near Abrazo Arrowhead will finish in September and another at Sierra Verde Park will be done is January.

“The city recently secured a significant win for long-term storage capacity within the Bartlett Dam expansion project following a successful steering committee vote in February,” Richards said.

Construction costs for this expansion will be released later this year.

Digging in deeper to the water portfolio comes with a cost.

Once the city begins pumping from long-term storage credits and groundwater, it is drawing from non-renewable water savings accounts — which will only last a limited number of years.

Glendale has been in stage one of its drought management plan since June 2022. The city’s 5% reduction in use means saving about $30 million a year.

“The drought management plan was designed in steps, so you really want to go through all of the steps. You wouldn’t want to go from stage one, which is voluntary for residents, right to stage three, which is mandatory for residents,” Environmental Programs Administrator Joanne Toms said.

Logan said not all cities are equally prepared for deep cuts in CAP supplies, even if they have enough groundwater to last them a few years.

This is largely an infrastructure issue. Some cities have the wells, pipes and pumps needed to move groundwater to a treatment plant and deliver it to the parts of town that currently rely on CAP supplies treated at a surface water treatment plant and one or two just don’t have that infrastructure in place.

“Our assessment is that Glendale is in pretty good shape,” Logan said.

Richard Smith
Senior News Editor | Glendale & West Valley Preps

rsmith@iniusa.org

Richard Smith has been with Independent Newsmedia since 2016, and worked at a Sun City-based news outfit covering the Northwest Valley for 22 consecutive years.

An NAU alum and lifelong Arizona resident, Richard began as a copy editor and page designer at Surprise Today and the Daily News-Sun, then rekindled his love of sports writing by taking the reins on West Valley Preps in 2008.

For most of the mid-2010s he was the Surprise editor and West Valley Preps reporter. Now he’s the West Valley Preps Editor and Surprise Associate Editor.

As COVID restrictions slowly lift, Richard is cautiously optimistic he will visit book stores, football fields and gyms again this fall.