2026 Aquatic Invasive Plant Treatments Planned for Hayden Lake The Idaho State Department of Agriculture (ISDA) is continuing its efforts to control Eurasian watermilfoil in Hayden Lake with a combination of diver removal and targeted aquatic herbicide treatments. A hired applicator will be applying ProcellaCOR®, an aquatic herbicide, to specific treatment areas in Hayden Lake targeting current growth of Eurasian watermilfoil. The 2026 treatment plan for Hayden Lake includes one diver-removal area and 11 chemical treatment areas. The current ISDA