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North System Renewal

Improving the safety and strength of the entire water system

Denver Water is in the early stages of a major project to replace aging infrastructure in our North System, which will help ensure the reliable delivery of clean, safe drinking water for generations to come.

view of denver from ralston site

By the numbers


years of system operation


length of Northwater Pipeline in miles


separate renewal projects

39.82763, -105.2547854

Denver Water’s North (or Moffat Collection) System sends water through the Moffat Tunnel into South Boulder Creek, then on to Ralston Reservoir in Arvada. From Ralston, a pipeline called Conduit 16 carries water to the Moffat Treatment Plant in Lakewood.

After more than 80 years of service, much of this infrastructure is in need of major maintenance or upgrades. That's why Denver Water is proactively embarking on four coordinated projects located in the 8.5-mile area between Ralston and Moffat. Early estimates anticipate the majority of construction will be completed in phases from 2017 through roughly 2023.

Renewal projects

Northwater Treatment Plant

The operators at Denver Water’s Moffat Treatment Plant maintain the oldest treatment facility in Denver Water’s system, and continue to produce safe, high-quality drinking water. Still, the treatment facility, built in 1937, has reached the end of its useful life and must be replaced.

Our engineering and operations teams reviewed the concept of upgrading and/or rebuilding the Moffat Treatment Plant at its current location, but qualitative and quantitative analyses found construction of a new plant by Ralston Reservoir to be the most cost-effective long-term solution. The Northwater Treatment Plant at Ralston Valley will offer efficiencies and flexibility to the entire system.

Ralston Reservoir Connection

Denver Water is making several upgrades to the valves and pipelines that release water from Ralston Reservoir's dam into the existing conduit that will become the Northwater Pipeline.

Valve upgrades will allow more flexibility in the case of emergencies or infrastructure inspections. Pipe replacement work will provide increased reliability and expanded system capacity in the future.

Northwater Pipeline

Denver Water is replacing and retiring Conduits 16 and 22, two pipelines that send untreated water from Ralston Reservoir to the Moffat Treatment Plant. Both are aging and nearing the end of their useful lives.

A single 84-inch diameter conduit, the Northwater Pipeline, will carry treated water 8.5 miles from the new Northwater Treatment Plant to the Moffat site for storage and distribution to customers.

The new conduit will help ensure a reliable treated water delivery system, scaled to handle the potential demand our service area may see in the future.

Moffat Distribution Site

The Moffat Treatment Plant site at 20th and Kipling in Lakewood is getting upgrades to accommodate the new Northwater Pipeline and transition to the site's new role as a distribution facility.

As part of this effort, Denver Water purchased property in 2005 at 20th and Quail, south of the plant, for future facilities. In the meantime, the property has provided storage for soil to backfill the Ashland Reservoir tank replacement site.

Also, Denver Water is adding to the system that handles materials removed from water during treatment. That material has historically been pumped to drying beds at Ralston, but the line must be put out of service during Northwater Pipeline construction. The centrifuge and pond will take the existing pumping system's place.


Project team email

Denver Water Customer Care: 303-893-2444