The Chelan County Knotweed project began in 2009 as a cooperative effort between Chelan County, the US Forest Service and the Washington State Department of Agriculture. The first phase of the project was to complete a county-wide survey of rivers and streams for invasive knotweed. Surveys began using funding from Forest Service Title II grants. The second phase is eradication or control of invasive knotweed populations found during the survey. Control treatments will be herbicide applications. Knotweed treatment in Chelan County began in 2010 with funding received from Washington State through the state knotweed program and additional funds from a Forest Health grant. Sites in and along stream corridors were the highest priority with the objective being to start at the top of a drainage area and move down. The treatment will need to continue over two to three seasons to be effective and more funding must be secured to complete the project.

Most knotweed found during surveys was the hybrid Bohemian Knotweed (Fallopia x bohemicum) although a number of patches were Japanese Knotweed (Fallopia japonicum) and 2 patches of Giant Knotweed (Fallopia sachalinensis) were located. Over 250 sites were located in 2009 across the county with an additional 882 sites reported from the Stehekin area by the National Park Service. In 2010, other area surveys yielded an additional 70 knotweed sites. Some sites remain to be surveyed, pending further grant funding.

Knotweed treatments in Mission Creek started in 2010 and will continue through 2013 with annual monitoring and re-treatment where needed. Once >90% knotweed control has been achieved, then these areas will be re-vegetated with native species. Currently, the plan is to seek grant funds for riparian revegetation actions in 2014-2016.

For more information about the Chelan County Noxious Weed Board, see their web site at
http://www.co.chelan.wa.us/nw/nw_main.htm