Renton Takes Action to Address Milfoil, Invasive Water Weeds

Two of Renton's most popular swim areas along Lake Washington will be closed on Tuesday, June 11 as the city tries to remove aquatic non-native weeds that flourish in Washington near the shore, including milfoil.

City parks officials said in a press release that an aquatic herbicide will be applied to the waters of the swim beach and boat harbor at Gene Coulon Memorial Beach Park and at Kennydale Beach Park. An additional treatment will occur on Wednesday, June 12, if it cannot be completed on June 11.

Milfoil is a feathery weed that can tangle up people, boat propellers, and fishing lines. It chokes out native plants, spreads rapidly to new areas and has few natural controls. Once established, it is very difficult to remove through mechanical removal efforts and aquatic treatment is the most effective solution. 

The process includes applying an aquatic herbicide below the surface of the water, which then settles on the plants. Gene Coulon Memorial Beach Park swim area and Kennydale Beach Park will be closed on June 11 to conduct the application.

City officials have deemed the herbicide "very safe", and the product is authorized by the Washington State Department of Ecology. Local residents living near the affected parks recently received notifications from the city's contractor, Aquatechnex LLC, about the underwater herbicide treatment.

For more information, contact Kelly Beymer, Parks and Golf Course Director at 425-430-6600.