Knock-out Knotweed

Beginning in 2002, the Noxious Weed Program began a project to locate and control the spread of knotweed species in Skamania County. The project is crucial to preserving the native plant species and riparian habitat throughout Skamania County. The knotweed species are identified as a Class B Noxious Weed by the Washington State Noxious Weed Control Board. Knotweed reduces plant biodiversity by shading out native vegetation and altering habitats. It can also increase the risk of flooding through dead stems creating impoundments in stream channels. If knotweed infestations are left untreated, there is substantial risk of soil erosion and stream bank failures following the removal of established stands in riparian areas.

In 2008, the Noxious Weed Program was awarded funds from the Community Salmon Fund and the National Fish and Wildlife Foundation for the purpose of restoring areas which were previously infested with knotweed. This project helped to address stream water quality, lack of plant diversity, erosion control and fisheries enhancement.

New for 2011, the knotweed control project has changed from primarily being sponsored by the Washington State Department of Agriculture and is instead funded by the National Fish and Wildlife Foundation. In 2011 and 2012, knotweed control will continue by county staff. However, control will transition from county staff to that of landowners. This is a victory for the weed program, as levels of knotweed are now maintainable by landowners.

If you have suspected infestations of knotweed, please contact us as soon as possible so that we may assist you. As our project continues to progress, there may be opportunities for volunteers to assist with survey, monitoring and revegetation. For more information please contact Cyndi Soliz at soliz@skamania.wa.us or by phone at 509-427-3942.