Zebra Mussels affecting Canyon Lake water supply

Water utility asks customers to limit usage after invasive mussels cover pump

Canyon Lake Water Service Company officials are urging that water usage in the area be limited to essential indoor use only due to a blockage at the lake intake pipes.

CANYON LAKE, Texas – An invasive species of mussels is choking off part of the water supply out of Canyon Lake, spurring the water utility to ask 8,000 customers to restrict their usage.

After seeing a sharp drop in water production at its largest water treatment plant, the Canyon Lake Water Service Company pulled one of the three water intake pipes out of the lake and found it encrusted with Zebra mussels. 

The microscopic larvae of the invasive species appear to have slipped through the protective screen at the end of the pipe, and the utility believes the other two pumps are similarly affected.

While it gets the pumps and intake pipes back in order, CLWSC is asking roughly 8,000 customers on the north side of the lake, the Bulverde and Spring Branch area, to keep from watering their lawns or doing any other nonessential outdoor watering.

"We have plenty of water for domestic household use, just not enough to meet that peak watering that people do in the summer," said CLWSC President Thomas Hodge.

Since the mussels were first discovered in Canyon Lake in 2017, the water utility has been expecting problems, doing semi-annual inspections of the intake pipes. 

The utility hasn't seen any indication yet of the mussels getting past the pumps and up into the intake pipes. However, even if that happened, utility officials said it would not be a safety issue.

"The water's safe to drink. Just restrict your outside watering until we let them know further," Hodge said.

The small mussels can also be a nuisance to boaters and swimmers. Since first being spotted in 2009, Zebra Mussels have been found in numerous lakes and waterways.

The mussels, or even their microscopic larvae, can hitch rides on boats. 

To help fight their spread, state rules require boats and onboard receptacles be emptied after leaving and before entering public bodies of fresh water.

About the Authors:

Garrett Brnger is a reporter with KSAT 12.