AUSTIN, Texas (AP) — Invasive zebra mussels continue to spread in Texas with experts saying the pests have reached a large inland reservoir.

The Texas Parks & Wildlife Department says zebra mussels were identified Oct. 18 in Richland Chambers Reservoir, a 44,000-acre (17806-hectare) site. The agency statement Monday said the area is less than 100 miles from Dallas, Waco and Tyler.

Experts earlier this year confirmed zebra mussels at Lake Austin and at Lake Travis, making about a dozen Texas lakes infested.

Zebra mussels were first found in Texas in 2009 at Lake Texoma, spanning Texas and Oklahoma.

The mussels can clog water pipes, damage boat motors and affect other aquatic life. Texas boaters, by law, must drain water from their vessels and onboard receptacles before leaving or approaching a body of fresh water.