Southwest Utah may not be growing as quickly as previously thought.
The Kem C. Gardner Policy Institute at the University of Utah has lowered its forecast for Washington County’s growth in the coming decades. The most recent projection released in late 2025 predicts that Washington County will add 175,255 people by 2065 and reach a total population of 384,339. That would be an 84% increase from 2025.
That’s still a lot of growth, but it’s significantly reduced from the institute’s previous projection. That forecast released in early 2022 predicted that Washington County’s population would increase 155% by 2060, adding 282,417 new residents.
Mallory Bateman’s team collected the data for that report during the upheaval of the pandemic, when migration into southwest Utah spiked. That made it challenging for demographers to predict how much would stick.
In the past few years, however, the data calmed, and it became clear that the previous forecast had overshot reality.
“We were maybe a little too rosy last time around,” the institute’s director of demographic research said. “And I think that probably had the biggest impact in Washington County.”
Moving the trendline down slightly created a big swing in expectations for the 2060s. A future with around 100,000 fewer residents could have big ripple effects for southwest Utah and its needs.
The Washington County Water Conservancy District, for example, uses the institute’s projection for its long-term water supply planning because it’s the best estimate out there, said General Manager Zach Renstrom.
“I have a lot of respect for the people who put these studies together, and I know the time and effort they put into this,” he said. “But one thing I know about these numbers is that they will be wrong, because we're never perfect.”
That’s why it’s important to keep water infrastructure plans as flexible as possible, he said, but that can be hard when projects may take 10 or 20 years to complete. The planned Graveyard Wash Reservoir is one example. Local leaders began the environmental review two decades ago, Renstrom said, and he hopes the project will obtain its final permit in the next couple of months and begin construction in 2026.
Still, he wouldn’t have changed any of their planning. Washington County is still expected to grow at the third-fastest rate in the state, trailing only Wasatch and Utah counties.
“If these numbers slow down, the worst that will happen is we may put certain projects off a little bit longer,” Renstrom said.
One such project could be the proposed Warner Valley Reservoir. The district has purchased the land for the reservoir site southeast of St. George, but may delay construction by five or 10 years if growth slows, he said. The same thing could happen with the second phase of the district’s wastewater reuse plan.
While Bateman said the latest projection didn’t directly account for the availability of water in southwest Utah, the previous projection did factor in the controversial Lake Powell Pipeline. That forecast noted the pipeline was expected to bring billions of gallons of Colorado River water to Washington County communities each year, boosting the water supply for more residents. But as megadrought and tensions between the basin states have escalated in recent years, the pipeline proposal became less feasible.
It’s complicated to guess how many people will live in Utah decades from now when a lot of the things that will impact that number — such as the national economic picture or policy decisions about housing, immigration and water — are out of the researchers’ control, Bateman said.
To update the projections, for instance, her team spent more than a year doing background research and sending their draft calculations to be reviewed by outside experts.
“It's not just us pushing in three new numbers and then we push a big button to get the end result,” Bateman said. “There is a lot of homework that goes in.”
In addition to correcting the pandemic-era trendline, she pointed to a few other factors that influenced Washington County’s reduced forecast.
For one, Bateman’s team got updated data from the U.S. Census Bureau on the ages of people who have moved to Utah from elsewhere in recent years. The numbers show that the average newcomer statewide was younger than previously thought, Bateman said.
That could reduce Washington County’s future population because this sunny, warm corner of Utah is still a big destination for retirees. So, if northern Utah’s newest transplants are younger than previously thought, they’re also further from retirement age. So, St. George may not see those residents relocate south until later in the century.
Utah’s falling fertility rates also dinged Washington County’s projections. People having fewer babies may have a smaller impact on St. George’s outlook than Provo’s, she said, because of southwest Utah’s older average age. But adding fewer kids to the mix still has a cumulative effect across the board, including in Washington County.
Declining fertility was a big factor in Bateman’s team revising the statewide numbers down, too. The latest projection expects Utah to grow 56% by 2065 to a total of 5.55 million people. The prior version had forecast the state to grow 66% by 2060. Salt Lake County is now forecast to add 370,327 people by the 2060s, rather than 483,889.
The latest report did not temper the growth outlook for everywhere in Utah, however.
Washington County’s northern neighbor, Iron County, saw its population forecast increase. That’s because the real-world data from the Cedar City area in the past few years has outperformed the previous projection, Bateman said. Iron County also isn’t impacted as much as Washington County by Utah’s new transplants being further from retirement age.
The jobs created by the new inland port in Cedar City boosted Iron County’s numbers, too. In more rural areas, Bateman said, one or two big economic projects like that might be enough to swing the forecast one way or another.
Millard County was expected to lose nearly 10% of its population by 2060. But recent plans to potentially convert the coal-fired Intermountain Power Plant there to a natural gas plant — rather than close it — changed the picture, she said. The area is now predicted to grow more than 23% by 2065.
The seeming approval of the Uinta Basin Railway project is another example, and it increased the forecasts for Uintah and Duchesne counties.
So despite a possible slowdown statewide, Bateman cautioned that Utah will still have plenty of growing pains as it looks to provide housing, jobs and water to hundreds of thousands more people in the coming decades.
“For a lot of areas of the state, those pinch points that we're feeling aren't necessarily going to go away,” she said. “So hopefully, we can keep planning and being strategic and smart about how we grow.”
Editor’s note: KUER is a licensee of the University of Utah but operates as an editorially independent news organization.
