How Salt Lake City is preparing for potential floods

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Last weekend the sounds of running water — trickling down gutters, flowing over rocks in City Creek and dripping off cars — suffused Salt Lake City as warmer temperatures finally graced the state after a long, gray and snowy winter.

With a record-breaking snow pack melting, Salt Lake City’s public works agencies are preparing to manage the flows, city officials said Monday as the temperatures climbed to 70 degrees.

With all this snow, many are thinking about the floods of 1983, Salt Lake City Mayor Erin Mendenhall said as she led off a news conference in Memory Grove Park in Salt Lake City. “But we are absolutely, undoubtedly much better prepared today for the record snowfall that we’ve received than we were in 1983.” Her update included a message meant to calm the anxiety building among residents around flooding in the Salt Lake Valley — especially for those who remember the city’s historic event from 40 years ago. “We’re here today to highlight the differences between 1983 and 2023,” Mendenhall said with the sun shining and City Creek rushing behind her.

Infrastructure built in the years following the flood

In the decades since flooding turned State Street into a river, two debris basins were installed in City Creek. The two concrete towers allow water to flow but keep branches, logs and boulders from clogging up the river. An excavator will be stationed at the basin to remove buildup that can then be hauled away by a dump truck. Roughly four blocks worth of debris built up in 1983, said Jesse Stewart, Salt Lake City Public Utilities deputy director.

“It’s just like having your own plumbing system clogged — it’s going to come out someplace else,” Stewart said. “But you can turn your water off, whereas here the water just kept coming and there was no place to go.”

The debris basins and piping system upgrades built in the decades since should help prevent that build up from happening again.

Little Dell Reservoir, built in the early 1990s, is also capturing runoff. The reservoir “was built for two important purposes,” Mendenhall said. “One as a flood control system and secondly as a water storage facility.”

“We are currently releasing water from Little Dell reservoir to make space available to hold the Parleys Creek runoff high up in the system upstream from Salt Lake City,” explained Laura Briefer, director of Salt Lake City Public Utilities. “That will take a lot of pressure off of the system when peak runoff occurs.” Creeks and streams in the canyons north and east of Salt Lake City provide more than 60% of the water supply for the city and Salt some surrounding suburbs.

Severe drought and ‘tragic capacity’

“This was not the case 40 years ago when Utah Lake and the Great Salt Lake at that time were at historically high levels,” Mendenhall said. “Today both lakes have probably a tragic amount of capacity.”

With so much capacity, the Great Salt Lake in particular could benefit from spring runoff. Recent reports have determined the Great Salt Lake water level to have increased 2.5 to 3 feet since November, but it’s still slightly lower than it was at this time last year.

“While we’re concerned about flood risk from this year’s record breaking snowpack,” Briefer said, “we’re also really grateful for the positive impacts of this snowpack.”

The snowpack water equivalent for the Provo River, Utah Lake and Jordan River Watershed sits at 229% of normal, Briefer said. “Which as a water manager I’m really happy about.”

And of course, the severity of flooding will depend on how quickly the state warms up. So far, things are looking good. “The forecast for the next week is perfect for a measured runoff,” Briefer said.

One of the most important things residents can do to prepare is make sure the storm drains around their homes are cleared of debris.

For additional reporting and resources you can read:

• The Tribune’s flooding resource guide.

• An explainer on how local water managers are managing runoff.

• Go to SLC’s Emergency Management page for resources and tips.