From the pipes under city streets to a field north of Golden, Denver Water’s five-year capital plan calls for major investments in its water quality and delivery system.

The $1.3 billion plan includes more than 100 major infrastructure and operational projects through the end of 2024.

“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.”

Northwater Treatment Plant

The top project on the plan in 2020 is the new Northwater Treatment Plant next to Ralston Reservoir.

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.

The North System Renewal 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.”

Excavation and pipe installation are underway at the Ralston location and construction will ramp up in 2021 and 2022 when more than 500 people will be working at the site.

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.

“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 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.

In Adams County, Denver Water will work on the Hazeltine Reservoir, which is part of the North Complex — a network of five gravel pits along the South Platte River north of Denver that have been converted to store water. The reservoirs will be fully operational by 2025.

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

Other projects

The capital plan also provides money to finish Denver Water’s Operations Complex Redevelopment Project in Denver, upgrade the hydropower unit at the Roberts Tunnel, replace the concrete spillway at Ralston Reservoir and purchase new heavy equipment and vehicles.

It also provides money for 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. The organization also strives to keep rate increases to a minimum and makes upgrades to meet regulatory and legal obligations

“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.”