Salt River Project opens Bartlett Dam floodgates to make room for spring snowmelt

As drought-busting winter storms continue to pile up snow, Salt River Project on Thursday began releasing water from Bartlett Dam down the Verde River toward metro Phoenix.

The dam, roughly 15 miles east of Carefree, holds back a Verde River that is poised to receive an unusually bountiful supply of snowmelt from Arizona’s high country. SRP officials expect the Verde’s reservoirs to fill soon, and to overfill if not partially drained first.

“We’ve got to make room on the Verde,” spokesperson Patty Garcia-Likens said.

The 13,000 square miles of mountains and valleys that supply the Salt and Verde rivers — and more than 2 million central Arizonans served by SRP’s system — have seen their second-best snowpack in 30 years. The system’s seven dams were about two-thirds full on Jan. 1, but now contain roughly 85% of capacity, or nearly 2 million acre-feet, even before the bulk of spring runoff.

There’s now no doubt that Bartlett and neighboring Horseshoe lakes will fill this year, SRP meteorologist Bo Svoma said. “We’re now locked in.” And the larger reservoirs on the Salt side, starting with Roosevelt Lake, are likely to come close.

At first, the releases that began Thursday will be hard to notice in the metro area. They’ll swell the canals that send water to city treatment plants. As March progresses, though, weather on and around the Mogollon Rim could cause officials to ramp up the releases to spill past Granite Reef Dam and into the usually dry Salt River bed in the east valley. SRP says motorists might expect to see water forcing the closure of McKellips Road as early as next week.

Environment:California ships toxic waste out of state, investigation shows. It ends up at this Arizona landfill

It’s the first such spill since 2019. In some wet years, water entering the river’s dry section can reach to and beyond Tempe Town Lake, potentially moving water past Phoenix and as far as the west valley.

In all, it’s possible that SRP could release 10,000 acre-feet this spring, or more than 3 billion gallons. That’s enough to support roughly 30,000 households for a year. System hydrologist Stephen Flora said water will sink into the desert, helping to restore groundwater that SRP has pumped in drier years.

At SRP’s request, the U.S. Bureau of Reclamation is studying options for altering Bartlett Dam to enable it to hold more water in good years like this one. The reservoir has lost some 45,000 acre-feet of storage capacity to accumulating sediment since its construction during World War II.

The billion-dollar dam raising would make water available beyond SRP’s traditional service area. That’s why tribes and fast-growing cities, such as water-challenged Buckeye, have signed on as potential partners. It’s one of several contemplated options Arizonans have for backfilling water that was formerly in reliable supply from the megadrought-stricken Colorado River.

Less than 15% of Arizona is currently in drought, mostly in far northern and western zones, according to the National Drought Mitigation Center. That compares to 85% two years ago. About a third of the state remains abnormally dry, mostly in the north, west and southeast.

In-state drought relief doesn't greatly ameliorate Arizona's long-term water supply outlook. Still looming is the Rocky Mountain snowpack's effect on the Colorado River, source of a third of the state's supply and two largely depleted reservoirs behind Hoover and Glen Canyon dams.

That snowpack currently is above average, but it will be months before it becomes clear how much will reach the reservoirs this summer. The Colorado remains afflicted by overconsumption and a multi-decade drought that will need more than one good season for meaningful recovery.

Brandon Loomis covers environmental and climate issues for The Arizona Republic and azcentral.com. Reach him at brandon.loomis@arizonarepublic.com or follow on Twitter @brandonloomis.

Environmental coverage on azcentral.com and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust. Follow The Republic environmental reporting team at environment.azcentral.com and @azcenvironment on Facebook, Twitter and Instagram.

Support local journalism. Subscribe to azcentral.com today.

This article originally appeared on Arizona Republic: With Verde River snowpack set to melt, SRP releases excess water