Thornton plots another pipeline route for its Poudre River water. Will Larimer County plug up its plans?

After a half-decade struggle by Thornton to claim thousands of acre-feet of water a year from the Cache La Poudre River near Fort Collins, the north Denver suburb is starting over with a new water pipe route.

As Thornton filed its latest application for a water pipe permit with Larimer County on Monday, officials had hope that they would face less resistance this time. But forces that have lined up against the city in recent years have no intention of dropping their fight against a 42-inch-wide pipe that would run across the county — arguing the project holds the potential to negatively impact landowners while doing nothing to improve the health of the Poudre.

They want Thornton to leave its water in the Poudre, allowing it to flow through Fort Collins before it’s taken out.

The issue will once again land in the laps of Larimer County’s three commissioners, who could either approve or reject Thornton’s new pipe alignment in a vote expected by March.

A no vote would jeopardize long-term growth plans in Thornton, Colorado’s sixth-largest city, for years to come by hampering the ability to access water it bought the rights for decades ago.

“Though it has been frustrating all these years, I firmly believe this is a better project with all the community feedback,” said Brett Henry, executive director of utilities and infrastructure for the city of Thornton. “It’s more clear about what to expect. There are less unknowns.”

Larimer County is the linchpin in Thornton’s $500 million, 70-mile water pipe project.

Adams and Weld counties already have given their blessings, and Thornton has built and buried seven miles of pipe near Windsor and Johnstown. It is scheduled to construct another 16 miles just north of the city over the next two years, at a cost of $64 million.

Thornton says the pipe’s new proposed alignment through Larimer County holds several advantages over a route the county rejected in early 2019. It would take 16 fewer miles of pipe in the county than the original route called for, and the project’s western terminus would avoid a number of neighborhoods that had raised concerns around construction disruption.

The city is also willing to move a proposed pump station well apart from homes. The station would be used to divert the water shares Thornton owns in the Poudre to a collection of reservoirs northwest of Fort Collins.

The pipe would then traverse 22 properties in Larimer County before crossing into Weld County and turning south. City spokesman Todd Barnes said Thornton already has begun discussions with most of the landholders about obtaining easements for the pipe.

“It’s all rural farmland and Thornton owns two of the properties,” he said. “We’ve consulted closely with Larimer County and we feel we’ve gotten as much feedback as we could. We’ve let the community’s input guide our process and our design.”

That’s not so, said Save the Poudre executive director Gary Wockner. The community wants the water left alone rather than fed into Thornton’s “zombie” pipeline, he said.

“Save The Poudre’s position will be, again, that the water should stay in the Poudre River all the way to Windsor,” Wockner said. “Using the river as the conveyance is cheaper, faster, smarter and restores water to the depleted Poudre River through Fort Collins and Larimer County.”

K.A. Wagner, who heads opposition group No Pipe Dream, said her organization once again will get people involved in fighting Thornton’s plans.

“When the Board of Commissioners denied the first application, they noted that Thornton had not explored ‘all reasonable alternatives,’ as required by” the local land use regulations, Wagner said. “They also expressed disappointment that the future of the Poudre was not considered.”

But Barnes said courts have ruled that Larimer County can’t force Thornton to keep the water it owns in the Poudre River. And doing so would be counterproductive for those who will rely on it in coming decades, he said.

“Why would we willingly put our high-quality drinking water down the Poudre River past three wastewater treatment plants and all the urban runoff?” Barnes said.

Henry, Thornton’s infrastructure chief, said “no engineer would tell you to pollute or degrade the water before you treat it.”

Thornton expects to bring an average of 14,000 acre-feet of Poudre River water to the city each year. An acre-foot of water, or about 326,000 gallons, is what two average families of four use in a year. The city currently draws the bulk of its water from the South Platte/Lower Clear Creek system, at 26,500 acre-feet per year, and from Standley Lake, at 6,000 acre-feet.

If Thornton can’t secure its future water supply, the failure could stymie long-term growth plans for the city of 150,000. Barnes said the city already had a 10,000-plus residential unit backlog due to “water uncertainty.

Barnes suggested the water stakes went beyond Thornton, potentially preventing the city from playing its part in helping to alleviate metro Denver’s affordable housing crunch.

Case in point: Maiker Housing Partners has paused the development of two affordable housing projects in Thornton due to the “uncertainty over future water delivery,” the head of Adams County’s housing authority told The Denver Post.