No powerboat has plied the waters of Standley Lake in more than four years.
And it doesn’t look like such watercraft will be allowed to launch any time soon on the 1,063-acre reservoir in Westminster, a source of drinking water for 350,000 people in metro Denver.
Northglenn Mayor Meredith Leighty recently penned a letter to Westminster saying her city “is not interested” in entering discussions to lift the trailered boat ban that was imposed in early 2019 over fears of introducing non-native mussels — namely quagga and zebra — to the lake.
“Northglenn’s water in Standley Lake is irreplaceable, valued at more than $209 million,” Leighty wrote in the Dec. 5 letter. “There is no level of risk that our community is willing to accept when it comes to protecting our drinking water supply.”
But Westminster Councilman Dave DeMott said it’s “not realistic” to operate on a zero-risk basis “as there is no area where zero risk exists in this world.” He’s heard from boating enthusiasts that they are “frustrated” with the ban, which was made permanent in late 2019.
“I have consistently heard water safety first from them and a desire to work together for a workable solution to allow boats on the lake,” DeMott said.
Westminster issued 473 permits for trailered boats in 2018, the year before the ban took effect. It took in nearly half a million dollars in permit fees.
Northglenn — along with Westminster, Thornton and the Farmers Reservoir and Irrigation Company — own the 42,000 acre-feet of water in the lake, which serves as the sole supply of drinking water for both Westminster and Northglenn.
Standley Lake, which is fed by three canals diverted off of Clear Creek, accounts for about a quarter of Thornton’s drinking water supply. It, too, is in favor of maintaining the trailered boat ban.
Any change in boating policy would have to be agreed to by the three cities.
The zebra mussel, native to eastern Europe’s Black Sea area, and the quagga mussel, native to Ukraine, arrived in the United States in the late 1980s. Colorado Parks & Wildlife Invasive Species Program Manager Robert Walters said both mussels “are extremely prolific at reproduction,” with one female mussel able to produce up to one million eggs per year.
The mussels clog intake pipes and water distribution systems and can “smother and kill native organisms,” Walters said. Each mussel can filter a liter of water a day, meaning they can “filter all of the nutrients out of the water, which is the base of the food chain.”
The mussels typically enter a body of water by hitching a ride on boats exposed to mussel-bearing waters. They are particularly adept at hiding in compartments on bigger boats — typically in the bilge and ballast systems — that are difficult to decontaminate.
“There is no technology that exists today that prevents the threat of aquatic nuisance species… from catastrophically damaging our water supply,” Leighty wrote in her letter.
Northglenn’s decision was likely re-affirmed by the September discovery of a single zebra mussel in Highline Lake State Park, northwest of Grand Junction. In late October, Colorado Parks & Wildlife announced more zebra mussels had been found in Highline Lake, giving the lake an official infestation listing.
CPW says Highline Lake is currently the only Colorado body of water infested with zebra mussels. No quagga mussels are known to exist in the state, though Lake Powell in Utah has them.
“We don’t see the value in risking our drinking water supply for the benefit of a small group of people,” said Tami Moon, Northglenn’s environmental manager. “That is the only place we have to store our water.”
Westminster began a decontamination and boat quarantine program in 2007 at Standley Lake Regional Park to stave off the introduction of the mussels but in 2018 found two dozen boaters “deliberately bypassing protective measures,” leading to the ban.
Britt Terry, who lived in Westminster for 20 years and now resides in Erie, started the Friends of Standley Lake group in 2019 to protest the prohibition on trailered boats. He said he knows of neighbors who have stowed or sold their boats, or even moved elsewhere, due to the ban.
He called the motorboat ban overreach and hopes the three cities will reconvene on the issue before their intergovernmental agreement on the operation of Standley Lake comes up for renewal in 2030.
“It was the equivalent of a prison finding cigarettes inside the facility and just shutting it down versus fixing the security breach!” he said of the ban. “I believe the city of Westminster should take the lead with regard to putting together a plan — with a goal of making it happen.”
Westminster Councilman Rich Seymour said the first step is getting everyone to the table.
“Discussions need willing parties to be at the table,” he said. “If Northglenn wants a zero-risk policy then we should close the lake to all uses and put a fence around it.”
It makes no sense, Seymour said, that all boaters have to suffer because a handful violated decontamination and quarantine protocols.
“The violators were discovered when staff used a database that showed boats that had checked into other lakes had been tagged to come back to Standley only,” he said. “Had we been using that database all along, the violators could have been banned individually.”
Seymour holds out hope that technology will advance to the point where preventing the introduction of quagga and zebra mussels on trailered boats can be done quickly and efficiently. He pointed to a “decontamination dip tank” that has been used at Lake Powell.
Boaters back their vessel into the tank, which is heated to more than 110 degrees, and the hot water kills the mussels in less than 10 minutes.
“It is known science that hot water kills zebra/quagga mussels,” Seymour said. “The boating community, from day one, was willing to pay for advanced cleaning systems via permit costs.