Hydrilla on Lake Tyler East grows 1270 percent since May

Red: Treatment area. Solid Green: Natives Submerged Species. Speckled Green: Hydrilla
Red: Treatment area. Solid Green: Natives Submerged Species. Speckled Green: Hydrilla

Posted by Ellen Krafve - email

Released by Susan Guthrie with the City of Tyler:

The City of Tyler Water Utilities Department will treat approximately 189 acres of hydrilla on Lake Tyler East starting Sept. 14. Earlier this month, 25 acres were treated; however, due to the rapid growth of the hydrilla, this second treatment has been approved by the State of Texas.

Biologists from Texas Parks and Wildlife estimate that one-fifth (537 acres) of the 2,500 acre lake is covered in the fast growing non-native plant. Since May, the amount of hydrilla has increased 1270 percent, up from an estimated 39 acres.

"It is important to keep the growth of hydrilla under control as it can be extremely invasive and out-compete native species and cover too large an area," said Dan Bennett, biologist with Texas Parks and Wildlife. "Hydrilla has a tendency to get out of control quickly," he added. "It is much more cost effective to keep it in check that to treat it when it is covering the entire lake."

The City plans to treat a 200 foot wide swath around the shore line in populated areas (as illustrated on the attached map). Only areas where hydrilla is growing by itself will be treated; not areas where native vegetation is growing.

"There are several key stakeholders who have interest in how the hydrilla is managed," said Greg Morgan, Tyler Water Utilities Director. "The fishing community is interested in preserving some hydrilla as a fish habitat. However, boaters and swimmers prefer to keep the hydrilla to a minimum because it gets in boat motors and can be dangerous to swimmers. Our goal is to strike a balance between the needs of all of the lake users."

All treatments are funded by the Tyler Water Utilities maintenance budget from proceeds from the sale of water. The City began treating hydrilla in 2006 as a result of feedback from the community. In 2007, nearly half of the lake, 1,250 acres, was covered in the plant and 630 acres were treated at a cost of $366,000.

"The City's approach to managing the hydrilla is to apply periodic treatments to keep it under control," continued Morgan. "If we do not schedule these periodic applications, the hydrilla could grow to a level that prevents boating and swimming in the lake."

Treatment plans are developed in conjunction with Texas Parks and Wildlife who conduct the surveys to determine the level of hydrilla in the lake.

The product that will be used to target the hydrilla is Aquathol, a treatment approved by the Federal Drug Administration for use in water sources. Residents who abut treated areas are advised to refrain from using lake water to irrigate landscaping for 14 days. The neighborhoods that will be affected by this advisory include: Pilot Point, Quite Bay, Lake Cove Estates, Big Oak Bay, Maegin Cove, Rainbow Ridge, Wilson's Retreat, and the northern part of East Lake Woods Estates.