Pend Oreille County to tackle flowering rush threat

NEWPORT — When residents along the Pend Oreille River hear the words “aquatic weeds,” they immediately think “milfoil.”

While Eurasian Watermilfoil is a big problem, there is another enemy lurking that can have a severe impact on the river’s future. That threat comes from flowering rush.

Flowering rush is an aggressive weed that spreads quickly and easily, creating dense stands that negatively impact native fish and plant species, and interferes with boating, fishing and swimming. It is also a great home for a species of snail and its parasites that cause swimmer’s itch. It is not recommended to manually pull or dig flowering rush, as that can break and release rhizome fragments, which is typically how this plant spreads.

While the plant can sometimes be identified by its cluster of pink flowers, it rarely flowers in this area. Observers will typically only see the leaves, which are thin, triangular-shaped stalks that can be submersed, emergent or floating. More information and photos can be found on the Washington State Noxious Weed Board’s website at www.nwcb.wa.gov/weeds/flowering-rush.

Flowering rush is a Class A noxious weed in Washington state, so eradication is a priority under state law. As such, Pend Oreille River residents in Washington will likely see contractors, hired by the Pend Oreille County Noxious Weed Control Board, performing aquatic weed control work in the river over the next couple of months. The contractors will be using Diver Assisted Suction Harvesting, as well as some herbicide treatment along the Pend Oreille River, primarily for management of flowering rush. Using the DASH method, the contractors are able to pull and remove all parts of the plant.

Landowners along the river were mailed notices earlier this month with the option to opt out of chemical treatment. Those who opted out will not be treated; however, if your neighbor chooses to have a contractor treat his/her frontage for milfoil, you may see a notice posted nearby or on your dock/shoreline, because it is a legal requirement to post within a quarter mile of a treatment area.

While milfoil is a nuisance to waterfront landowners and recreationists, it is only designated for control in lakes in Pend Oreille County, so it is up to landowners to take on that task, either themselves or by hiring contractors. If performing the work yourself, be sure to adhere to any permitting requirements. There are other management options besides herbicide, such as hand tools to remove milfoil and other aquatic weeds from the shoreline or around the dock.

The Weed Board has some of these tools available to rent. While the Weed Board is not funded for control of milfoil, there is cost-share available for landowners along the Box Canyon Reservoir of the Pend Oreille River, who use non-herbicide methods to manage aquatic weeds. The cost-share program is through partnership with the Pend Oreille Public Utility District. There is limited funding, so it is first-come, first-serve for reimbursement up to 100% (up to $500 per individual or $1,000 per group). Examples of covered costs include purchase of hand tools or hiring DASH contractors.

If you are interested in the aquatic cost-share program, contact the Weed Board or visit our website at www.pendoreilleco.org/weedboard and click on the Aquatic Workshop & Cost Share tab. For more information on the cost-share program and weed management methods, look for the Weed Board’s aquatic workshop held each July. You can also view videos from this year’s program on the aforementioned website.

Information: email, noxweedinfo@pendoreille.org; or by phone, 509-447-2402