It has been 12 years since a zebra mussel infestation was first identified in Texas, but the fight against their spread continues.
The invasive mollusk species made its first known infestation in Lake Texoma in 2009 and has since spread to Lake Lewisville, Lake Grapevine and Lake Ray Roberts. North Texas reservoirs such as Lake Ray Hubbard have been categorized by parks officials as “suspect,” meaning juvenile mussels or larvae were found once in the water.
Collin County’s Lake Lavon is one of five lakes with the distinction of “positive,” meaning zebra mussels or their larvae were found in the reservoir on more than one occasion without any sign of reproduction.
Lake Lavon is one of two zebra mussel-containing lakes that the North Texas Municipal Water District (NTMWD) has rights and access to, with the other being Lake Texoma.
“In 2009, when that population was identified as zebra mussels, it spurred some action on our part,” explained Galen Roberts, the district’s Assistant Deputy of Water Resources.
Revelations of the mollusk’s infestation in Lake Texoma prompted the $300 million construction of a pipeline that transfers the lake’s water to NTMWD’s water treatment plant in Wylie, a stretch between the city and Sherman that exceeds 70 miles. This pipeline was constructed due to the National Invasive Species Act of 1996 and the Lacey Act of 1900, two conservation laws passed by the U.S. Congress that effectively ban transport of non-indigenous species into foreign bodies of water. The former law specifically restricts such transport from discharged water from boats or other vessels, while the latter one prohibits the importation of “injurious wildlife.”
The Lake Texoma water treatment pipeline complies with these laws insofar as zebra mussels do not survive the journey due in part to the water’s slow transport in a closed environment, Roberts explained.
Still, other efforts are actively being made to curtail potential or ongoing infestations. In partnership with the U.S. Geological Survey, the district has actively collected and tested water samples from its reservoirs and sent divers to periodically inspect them for traces of zebra mussels or other invasive species.
In NTMWD’s Bois D’Arc Lake, officials are routinely cleaning off filtration screens from its water intake structures.
“We’re still actively constructing it; it’s still filling,” Roberts said. “Today, there hasn’t been public recreation on the lake since the lake isn’t really there yet, but that day’s coming. We recognize that. We’re trying to do what we can in our partnership with Parks and Wildlife to prevent spread or infestation from becoming prevalent in Bois D’Arc.”
But above all else, the district is reiterating earlier messaging from Texas Parks and Wildlife to “Clean, Drain and Dry.”
“We have a lot of new people moving to our area [who] might not be familiar with zebra mussels and the problems they can pose,” said Helen Dulac, NTMWD’s Water Resource and Public Education Manager. “It takes all of us working together to stop the spread of zebra mussels and other invasives … It’s not just boaters – it’s also peddlers and anglers and anybody who gets into the lakes of Texas.”