The long-awaited vision of Lake Nighthorse supplying water to the parched, water-strapped western part of La Plata County is finally coming to fruition.

This spring, a pipeline was completed that brings water from Lake Nighthorse, just south of Durango, to a reservoir 4.6 miles away called Lake Durango, on the south side of U.S. Highway 160, about 7 miles west of Durango.

And just last week, a seven-day test to demonstrate the system could pump large quantities of water over a prolonged period of time was successful, said Ken Spence, president of the La Plata West Water Authority Board of Directors.

“It’s a major a milestone: Now, we have a way to get water to the Dryside,” Spence said. “(This project) is one of those things that’s been discussed for 10, 20 years. But you have to do it in steps, and this is a huge one.”

While most parts of La Plata County have reliable sources of water through rivers, wells or water storage projects, the county’s western half has always dealt with a shortage of water.

As a result, residents throughout the unincorporated parts of western La Plata County have either had to haul water, an expensive endeavor, or drill wells that are often unreliable in dry years or not potable, Spence said.

But about 10 years ago, La Plata West Water Authority, created to provide domestic water to rural southwestern La Plata County, along with the Southern Ute Indian Tribe and Ute Mountain Ute Indian Tribe, partnered to build a pipeline that would take water out of the soon-to-be constructed Lake Nighthorse over to the western part of La Plata County. The three entities were able to complete an outflow structure just before the dam was filled in 2013.

During the process, water managers with the Lake Durango Water Authority joined the project, hoping to secure more water reserves for its communities just west of Durango along the U.S. Highway 160 corridor.

The plan, Spence said, was to build three different legs of the pipeline to service the needs of the two Native American tribes, La Plata West Water Authority and Lake Durango Water Authority.

The test of the system last week proved it capable of delivering water to Lake Durango.

For Lake Durango Water Authority, the long-awaited accomplishment means the district can finally start selling taps after La Plata County placed a moratorium on the previous water district when it over-sold taps that didn’t take into account drought years.

Lake Durango Water Authority has about 1,300 active customers, said Charlie Smith, general manager. The water purchased out of Lake Nighthorse from the Animas-La Plata Project will be able to serve an additional 400 homes.

Smith said there are more than 100 people on the wait-list for a tap, which costs about $14,000. A customer who uses 3,000 gallons of water can expect a bill of about $67, Smith said. A 30-year build-out plan could service 250 more homes.

“In the Lake Durango water area, the water supply has been solely runoff and lower-priority water rights on the La Plata River, which is over-appropriated,” Smith said. “So in a dry year like this, there’s been zero water delivered.

“By completing this part of the project, Lake Durango has shored up its water supply.”

Smith said the test run pumped 25 acre-feet out of Lake Nighthorse into Lake Durango.

“That is actually the first beneficial use of water out of Lake Nighthorse for ... anyone in the state of Colorado,” Smith said.

For residents in the La Plata West Water Authority area, the successful pumping test means they could see water delivered to 150 homes as early as a year from now, Spence said.

La Plata West Water Authority on Tuesday will put out bids for construction of its pipeline to run treated water from Lake Durango to a connection line to its system near Blue Hill.

Eventually, La Plata West Water Authority intends to build its own water-treatment plant, allowing it to pump directly from Lake Nighthorse.

“But that’s down the road a ways,” Spence said.

La Plata West Water Authority can serve up to 400 customers through water delivered via Lake Durango. But the district hopes its own treatment plant would serve the needs of an estimated 1,500 properties.

Efforts to launch smaller-scale projects to bring domestic water to the western side of La Plata County have been ongoing ever since the massive Animas-La Plata Project, which involved dams and transmountain diversions, was downsized.

Lake Nighthorse was a remaining relic of that project, built to fulfill water rights to Native American tribes. Some water is available for purchase, as La Plata West Water Authority and Lake Durango Water Authority have done.

“People have tried out here for a lot of years to get water,” Spence said.

The entire cost of the pipeline project was $5.3 million, Smith said, funded by the four involved entities.

jromeo@durangoherald.com