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Cottonwood Heights Journal

Big Cottonwood Water Treatment Plant set to be completely reconstructed within three years

Dec 01, 2023 08:55AM ● By Cassie Goff

“Here’s a more interesting look at what the site looked like when the plant was put into service in the 1950s,” Assistant Manager Winsor said. (Photo courtesy of Wayne Winsor/ Metropolitan Water District of Salt Lake & Sandy)

Have you ever wondered about the history and infrastructure of the water treatment plants in both of the canyons surrounding the city of Cottonwood Heights? Metropolitan Water District of Salt Lake & Sandy General Manager Annalee Munsey and Assistant Manager (and Engineering Manager) Wayne Winsor attended the Cottonwood Heights City Council meeting on Nov. 7 to share details of their history, infrastructure and future. 

The Water District of Salt Lake & Sandy was originally established in 1935. It was the local sponsor for the Provo River Project which built the Deer Creek Reservoir and Dam. 

Those previous efforts helped to build the Salt Lake Aqueduct in 1951. (Now, the Salt Lake Aqueduct is made up from a 69-inch insider diameter and 84-inch outside diameter of reinforced concrete pipe.) 

“Back in the day, they would put chlorine into the water in Deer Creek Dam and that’s what got delivered to the public,” Winsor said. 

When the federal government came out with a new drinking water plan, the Little Cottonwood Water Treatment Plant was constructed. Now, the Little Cottonwood Water Treatment Plant currently filters about 150 million gallons of water per day.

In addition, there is a 10-million-gallon reservoir in the Enchanted Hills area. Winsor reported that reservoir is primarily used for fire storage water to service the Cottonwood Heights, Sandy, and Salt Lake City area. 

Currently, the Metropolitan Water District has seven members on their Board of Trustees – five appointed by Salt Lake City Council and two appointed by Sandy City Council. Looking into the future, the Metropolitan Water District has begun to plan and construct their Cottonwood Connections project. 

“With our recent master plan and system improvement studies, improvements need to be made for seismic response and capacity,” Munsey said.

The Metropolitan Water District analyzed updating or re-constructing the Big Cottonwood Water Treatment Plant. It was ultimately concluded that the plant needed to be completely replaced. Winsor reported that it will be completely torn down and rebuilt over an estimated timeline of about three years.

The pipeline along Wasatch Boulevard crosses the fault lines four to five different times. In the 1960s, Winsor reported that construction of the infrastructure did not include any rebar across the concrete slabs so they need to get into the pipeline to construct a steel pipe with a polyurethane lining for protection against seismic activity.

“If mother nature shakes that pipeline, it will crack, and it won’t hold water. It’s susceptible to an earthquake,” Winsor said. 

The Big Cottonwood Water Treatment Plant currently has an annual supply of around 24,3000 acre-feet of water, which is the rough annual indoor water supply for about 110,000 people (or about 25% of their service area). Taking out the Big Cottonwood Water Treatment Plant for three years for reconstruction would completely drain the water reserves throughout the service infrastructure. In recognizing this potential issue, and the need for a new pipeline, the Metropolitan Water District decided to put these two projects together. 

“The public wins here. We are able to conserve water and we will have a pipeline we can use for the future,” Winsor said.

Since the Utah Department of Transportation (UDOT) has plans to resurface Big Cottonwood Canyon Road, the Metropolitan Water District has to be done with their construction east of Wasatch Boulevard by June 2024. 

For more information about ongoing construction projects for the Metropolitan Water District of Salt Lake & Sandy, residents can sign up for their email subscription list and/or visit their project website at: λ