Tarps laid down in October to smother a colony of zebra mussels at Lake Waco failed to kill all of them, but city of Waco officials are holding on to hope that the infestation won’t spread.
City and state parks officials earlier this month removed tarps from a section of the lake the size of a football field near Ridgewood Country Club. An inspection of 50 rocks found two live but “sickly” zebra mussels, city water quality administrator Tom Conry said.
“We don’t know that they’re viable,” Conry said. “They’re not absolutely dead. . . . We hope that we do not have a viable population.”
In the meantime, the city has ordered equipment to spray bleach on water intake equipment to keep mussels from clogging pipes. The Eurasian species, which has reached Texas in the last few years, is known for upending ecosystems and wrecking water infrastructure by forming dense colonies.
City crews plan to do monthly inspections at 10 shoreline spots around the lake to see whether zebra mussels have spread. Texas Parks and Wildlife Department scientists in the next few weeks will perform a water analysis to look for traces of zebra mussel larvae or DNA. TPWD scientists found no such traces in their last sampling Dec. 4.
Brian Van Zee, a Waco-based inland fisheries regional director for TPWD, said in a statement that the tarp project may yet prove to have been successful.
“While we were not able to get 100 percent control of the zebra mussels, we do believe that we were successful in creating anoxic conditions over much of the area,” he said. “At this point, we can’t say if enough survived to create a reproducing population, but at least we may have slowed them down.”
Scientists discovered the mussels Sept. 26 at the Ridgewood boat ramp and quickly traced their origin to a work barge that a Belton contractor had brought in earlier that summer to do work for the country club.
State law requires watercraft to be cleaned before moving to a new body of water to prevent zebra mussel infestations.
Conry said the contractor’s “flagrant disregard of the rules” is upsetting.
“This guy is costing my customers money because he chose not to follow the rules,” he said.
City, state and U.S. Army Corps of Engineers officials worked together in October to install the tarps, hoping to deprive the small colony of oxygen.
For the past two years, the city of Waco has done summertime boater education and inspections at ramps around Lake Waco to prevent the spread of zebra mussels, and it will sponsor that program again this year on weekends between Memorial Day and early August.