EDI Staging Environment
The Cedar River Watershed provides drinking water to Seattle and the forest surrounding the drinking water reservoir is closed to public access and managed for invasive species. In 1999, the invasive plant knotweed was detected in the watershed and control was limited to manual and mechanical methods due to an herbicide moratorium intended to prevent broadcast spraying of roadside vegetation. These methods were largely unsuccessful and impractical for controlling acres of knotweed growing in remote locations of the watershed. In 2010, Seattle Public Utilities passed the first ordinance through Seattle City Council to approve the limited use of imazapyr to control knotweed in the watershed for three years. There have been five successive knotweed ordinances passed, allowing for herbicide control of knotweed in the watershed from 2010-2025. The reports included in this package are provided to Seattle City Council annually as a requirement of the ordinance. The data table provides the control history since the passage of the first ordinance and includes information about patch size and amount of imazapyr used.
EDI is a collaboration between the University of New Mexico and the University of Wisconsin – Madison, Center for Limnology:
