Crews start treating section of Eno River for invasive aquatic weed Hydrilla

The North Carolina Division of Parks and Recreation said the treatments will be ongoing through September.

Hydrilla can grow rapidly and create thick mats on the surface of lakes, rivers and other waterways.

The herbicide treatment follows a two-year pilot that significantly reduced Hydrilla without impacts to the rest of the ecosystem or to human health, DPR officials said.

The summer treatments will be targeted in a 16-mile area of the river between Hillsborough and an area on N.C. Highway 501 in Orange and Durham counties.

The herbicide will be applied in a concentration well below limits set by the EPA and is safe for humans, fish and wildlife, officials said.

Property owners adjacent to the treated section of the river will be cautioned regarding the use of river water for irrigation during Hydrilla treatment.

“Pesticides approved for aquatic sites have passed a rigorous testing process. Fluridone is one of the least toxic among those,” said Rob Emens, program manager for N.C.’s Aquatic Weed Control Program. “At the rate it will be applied in the Eno, no restrictions on water use will be triggered except for irrigating certain plants and seedlings.”

Hydrilla was first discovered in the Eno River watershed in the early 1990s in Lake Orange, which is located upstream of Hillsborough. In 2009, biologists confirmed Hydrilla in another upstream reservoir, West Fork Eno Reservoir.