Thurston County Public Works’ Noxious Weeds program has been hard at work removing an invasive species, floating primrose-willow, from Chambers Lake in Lacey. 

Floating primrose-willow (Ludwigia peploides) has egg-shaped leaves with reddish stems and bright yellow flowers. It grows along the shores of slow-moving streams or lakes. This plant comes from parts of South and Central America. Floating primrose-willow crowds out waterways, disrupts native habitats, and makes recreation areas unusable or unsafe. Its sponge-like roots trap soil and change water flow and quality where it’s found. Because it’s so harmful, state law requires it to be completely removed wherever it’s found. 

It was discovered in 2023 for the first time in Thurston County by the Department of Ecology. Thurston County Public Works’ Noxious Weeds program developed a treatment plan and treatment began in 2023, after working with experts from across the region. 

This is the third year of treatment, and the team is already noticing a difference. Over the past three seasons, herbicide was only used during one season. Staff have prioritized hand pulling to treat plants on the lake. This year, early-season surveys done by staff showed fewer plants around the lake. Because of these results, Noxious Weeds staff opted to only remove plants by hand. Noxious Weeds staff notified landowners around the lake through mailings before pulling plants from private shorelines. The team pulled roughly 1,500 lbs. of plant material from the shoreline over three days.

This project shows the dedication of the Public Works team in protecting their local environment and our community from the harm of invasive species. Keep up the good work! 

To learn more about projects Noxious Weeds is involved in, visit their program webpage.