An explosion in mussel populations in Lake Powell and low water levels there are contributing to a record number of cases of boats in Colorado being found to host the invasive animals.
Colorado Parks and Wildlife says boats that recently have been on Lake Powell are posing a serious threat of infesting Colorado lakes and reservoirs with quagga and zebra mussels.
CPW and other inspectors so far this summer have found a record 43 boats containing mussels, compared to the previous record of just 26 boats. Thirty-two of this year's cases involve boats that came from Lake Powell.
Among the cases so far this year are four at Highline Lake, three at Sweitzer Lake in Delta County in August alone, two at Ruedi Reservoir above Basalt, along with cases at Blue Mesa Reservoir, Lake Granby and numerous other places around the state.
"It's definitely a statewide problem. We see them at reservoirs all across the state," said Elizabeth Brown, CPW's invasive species coordinator.
Mussels that can cover boat propellers and hulls also pose the threat of clogging lake and reservoir waterworks, affecting irrigation, domestic water supplies, flood control and hydropower generation. So far Colorado's inspection program and cooperation from boaters have helped keep the state free of mussel infestations, but this year's experience is showing the extent of the challenge the state faces in maintaining that status.
Brown said that while Powell isn't the only place boats with mussels are coming to Colorado from, the abundance of mussels there and its proximity to Colorado for boaters are contributing to the problem Powell is posing.
She said mussels have only been in Powell for a couple years.
"Now that they're there, the population is booming, and Powell's just a weekend boat trip for Colorado residents. It's very close to us," she said.
Adding to the problem are low water levels in Powell due to the drought, which has left more mussels exposed.
"When you bring that water level down to where the mussels are living, then the boats are in contact with them more," Brown said.
She said CPW hasn't had conversations about possibly prohibiting boats that have been on Powell from going onto Colorado lakes and reservoirs.
"We're inspecting boats and decontaminating boats and working with the boat owners and that's our strategy at the moment," she said.
In a CPW news release, Ed Keleher, manager of Sweitzer Lake State Park, said that in the case of the August mussel incidents there boat owners were responsible and told inspectors they'd recently been to Lake Powell.
"That's very helpful and we really appreciate people telling us where they've been because when we know a boat has been to Lake Powell we know it is at high risk for mussels," Keleher said.
CPW is emphasizing the need for boat owners to inspect not just obvious places like boat hulls, but ropes, live wells, fishing gear, buckets, paddles, recreational equipment, paddle boards, boat trailers — basically anything that has touched the water. Ballast tanks used in cases such as in wakeboard boats that help keep the boats heavy and low in the water require particular attention; Brown said they can pose a challenge because it's hard to fully drain them.
"They're kind of like floating aquariums," she said.
CPW is emphasizing the need to clean, drain and dry not just boats but all ancillary gear, such as by wiping down ropes and other equipment and letting it dry in the sun.
Brown said anyone bringing in a boat from out of state can contact CPW to arrange an appointment for an inspection.
Thanks to action by state lawmakers, starting next year a $25 aquatic nuisance fee will be applied to motorized watercraft and sailboats owned by Coloradans, with the fee being $50 for nonresidents, to help pay for inspection and decontamination efforts.
Such boats are currently prohibited on some waters in Colorado due to lack of inspections programs at those sites. Some water bodies aren't owned or operated by CPW, but Brown said the agency is hoping with the revenues from the new fee that it will be able to get an inspection program going at Harvey Gap State Park outside Silt so the reservoir there can be reopened to motorized boats.
Also, CPW said this week that thanks to funding provided by the Northern Colorado Water Conservancy District, inspection and decontamination stations at Grand Lake, Shadow Mountain Reservoir and Granby Reservoir will remain open longer than expected this year, allowing for boating through Dec. 2.