Walla Walla, WA -- The U.S. Army Corps of Engineers’ Walla Walla District (Corps) will be treating the invasive plant species, reed canary grass, in Yellowhawk Creek and Garrison Creek on August 6 and 7.
“Reed canary grass is a highly invasive weed that has the ability to restrict waterways. If left unchecked, it could degrade fish passage and, over the past 10 years, it has narrowed the creeks significantly,” Natural Resources Specialist Jeremy Nguyen said.
The Corps consulted with National Marine Fisheries Service, U.S. Fish and Wildlife Service and herbicide manufacturers to determine the best herbicide application for this location. The resulting decision was to use aquatic-labeled herbicide Clearcast on the reed canary grass in an attempt to remove it from the creeks to improve flows.
There is no intended impact to downstream homeowners or irrigators during or after the treatment. The label recommends irrigation intakes within 100 feet of the treatment area not be used for the day, however, there are no known intakes within 100 feet of the treatment areas. If downstream homeowners or irrigators have concerns, they may choose not to use the water on August 6 and 7.
For more information about the herbicide application, contact the Mill Creek Project Office at 509-527-7160. More information can also be found on the Mill Creek Facebook page at https://www.facebook.com/millcreekdam/.
Release no. 20-113