Wichita ? Zebra mussels that have moved into Cheney Reservoir are no threat to Wichita’s drinking water, officials say.

The lake provides about 60 percent of the city’s reservoir, and many larvae — but no adult zebra mussels — were found there last week.

“It’s not the best news, but it’s a challenge we’ll overcome,” said Mike Carney, Wichita Water and Sewer Department superintendent of production and pumping.

The mussels have moved into about 20 states in recent years, causing millions of dollars of damage by clogging intake structures for water supply plants.

“We’ll have to spend some money, but we’ll protect our water supply,” Carney said.

Biologists think zebra mussels or their larvae are transported in water or vegetation hauled by ships, boats or boat trailers.

The zebra mussels are prolific and are known to out-compete native mussels and small fish for food in many waters.

They were first brought to the Great Lakes region in bilge water from barges in the late 1980s and quickly spread through that region and down connecting river systems.

Carney said the Water Department, which started planning last summer when zebra mussels were discovered at El Dorado Reservoir, would hire a consultant and figure out the most effective way to fight the infestation.

“It could be in the millions of dollars,” Carney said. “We have no idea.”