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$1.5 billion investment on tap for water system

New treatment plant, the Lead Reduction Program, water main upgrades and more make up five-year capital plan.

From replacing lead service lines and delivery pipes under city streets to building a new treatment plant north of Golden, Denver Water’s five-year capital plan calls for major investments in its water quality and delivery system.

The $1.5 billion, five-year capital plan includes about 100 major projects through the end of 2025. To pay for this critical system, Denver Water relies on water rates, bond sales, cash reserves, hydropower sales and the fees paid when new homes and buildings are connected to the system.

“As the water supplier for a quarter of the state’s population we’re always looking to the future,” said Bob Mahoney, chief engineer at Denver Water. “When we develop our capital plan, our top priorities are ensuring public health with safe drinking water and maintaining a high level of reliable service now and in the future.”

Lead Reduction Program

A major part of Denver Water’s capital plan is the Lead Reduction Program, which launched in January 2020.

The program will reduce the risk of lead getting into drinking water by replacing over the course of 15 years an estimated 64,000 to 84,000 old lead service lines put in place decades ago across its service area. It’s the utility’s biggest public health campaign in its more than 100-year history.

The Lead Reduction Program will replace the estimated 64,000 to 84,000 lead service lines in Denver Water's service area at no direct cost to the customer. Photo credit: Denver Water.


The water Denver Water delivers to customers is lead-free, but lead can get into drinking water as it passes through customers’ lead service lines and indoor plumbing that contain lead. In Denver Water’s experience, homes built prior to 1951 are more likely to have lead service lines, the customer-owned pipes that bring water into the home from Denver Water’s delivery pipe under the street.

Customers enrolled in the program are being provided with water pitchers and filters that are certified to remove lead. Filtered water should be used for drinking, cooking and preparing infant formula until six months after the lead service line is replaced.

In March 2020, Denver Water also raised the pH of the water it delivers to customers to help reduce the risk of lead getting into water as it passes through customers’ internal plumbing that may contain lead.

Northwater Treatment Plant

Work continues on Denver Water’s new, Northwater Treatment Plant next to Ralston Reservoir north of Golden.

The plant is part of Denver Water’s North System Renewal Project, a $600 million, multiyear project that includes an 8.5-mile water pipeline and modifications to the Moffat Treatment Plant in Lakewood, which was built in the 1930s.

Construction is underway at Denver Water's new Northwater Treatment Plant along Highway 93, seen at the top of the picture, north of Golden. Photo credit: Denver Water.


The North System Renewal Project marks the largest capital investment project in Denver Water history, even topping construction of the 23-mile Roberts Tunnel under the Continental Divide in the 1950s and 1960s.

“Northwater will be a state-of-the-art facility that will help us meet the water quality challenges of the future,” said Nicole Poncelet-Johnson, director of water quality and treatment at Denver Water. “The plant will feature modern water filtration and disinfection technology, improve reliability and utilize renewable energy.”

Progress at the site of the new plant has moved quickly, with sections of pipe and walls for several of the new buildings already in place. Over the summer, bulldozers and trucks moved earth to make way for the two, 10-million-gallon storage tanks, which will be mostly buried to avoid obstructing the view from Highway 93.

Up to 400 people have been working at the site on any given day during 2020, with dozens more working remotely — one of the many layers of protections put in place to keep people associated with the project safe from the COVID-19 virus.

The Northwater plant will include 14 buildings once it’s complete and be able to treat 75 million gallons of water per day. It also has the capability to be expanded to treat 150 million gallons per day in the future if needed. It’s scheduled to open in 2024.

Water main investments

The five-year plan also includes an aggressive approach to replacing water mains across Denver Water’s 335-square-mile service area in the city of Denver and surrounding suburbs.

Denver Water crews installing a new water main pipeline. Photo credit: Denver Water.


“We’re increasing funding to our water main replacement program to reduce the number of main breaks in our aging system,” said Garth Rygh, director of water distribution at Denver Water. “We replace about 106,000 feet of pipe a year now and have a goal of increasing that to about 140,000 feet of pipe every year by 2024.”

Water storage

The capital plan also includes money for design work on the Gross Reservoir Expansion Project in Boulder County. The project cleared its final federal hurdle on July 16, 2020, when the Federal Energy Regulatory Commission gave its approval for the project and ordered Denver Water to proceed with design and construction.

The project will raise Gross Dam by 131 feet and triple the amount of water the reservoir can hold.

Expanding Gross Reservoir will provide greater balance between Denver Water’s north and south collection areas. Pre-construction work includes testing dam designs, such as the study of the new dam’s spillway that’s underway at Colorado State University’s hydraulics laboratory.

Expanding the reservoir requires raising the dam 131 feet by placing new concrete on the existing structure. Image credit: Denver Water.


Denver Water also is completing work on three treated-water storage tanks at its Hillcrest location in southwest Denver and building a new pump station at the site.

Other projects

During October, construction crews broke ground on the new, 122,000-square-foot Hydro building that is part of Colorado State University’s new Spur campus at the National Western Center north of downtown Denver. A portion of the building will house Denver Water’s new, state-of-the-art water quality laboratory, replacing an existing, aging lab at the Marston Treatment Plant.

Laboratory staff currently perform more than 70,000 water quality tests every year, work that helps ensure the water Denver Water distributes to customers goes above and beyond state and federal drinking water regulations. The new lab will be capable of performing more than 200,000 tests per year.

And being a part of the larger campus also provides more opportunities for the research and development of water quality applications.

A portion of the Hydro building at the CSU Spur campus at the National Western Center will house a new, state-of-the-art water quality laboratory. Image credit: hord|coplan|macht.


The capital plan also provides money to upgrade the hydropower unit at the Roberts Tunnel, replace the concrete spillway at Ralston Reservoir and purchase new heavy equipment and vehicles.

Denver Water also is investing in forest health projects designed to protect mountain watersheds, the locations snow and rain pass through before flowing into the rivers and streams that fill Denver Water’s storage reservoirs.

Being financially responsible

Denver Water has a history of being proactive with maintaining and improving its vast network of dams, pipes, canals and treatment plants, according to Mahoney.

“Keeping our system running to bring water to the taps is an extensive, year-round process,” Mahoney said. “We always look at what we need, what we can afford and what resources are available to get the job done.”

Crews installing a major new pipeline in Jefferson County, replacing one that dated from the 1930s. Photo credit: Denver Water.