History of Lake Treatments
Date Plant Treatment Area / Notes Method of Treatment Approx. Cost
8/10/26 Eurasian Watermilfoil 1.2 acres in south basin, south of the boat launch ProcellaCOR $2,200
8/10/26 Fragrant Water Lily ~3 acres around railroad trestle (Map) ClearCase (Imazamox) $4,566
8/10/26 Submerged Nuisance Weeds ~0.3 acre - boat passage under trestle (Map) Aquathol K (Endothall) $3,615
10/15/25 Eurasian Watermilfoil 1.8 acres, near the boat launch and at the south cove of the lake. ProcellaCOR $2,600
July 2025 Fragrant Water Lily Planned treatment around trestle was cancelled due to early die off of fragrant water lily. None / Not Applicable $0
History of Steering Committee Achievements
Date Action / Achievement
1/1/23 Pattison Lake Management District Created
6/1/25 Final Integrated Aquatic Vegetation Management Plan Adopted
7/31/26 PLMD awarded IAVMP implementation grant by Dept of Ecology ($59,800)
7/31/26 PLMD awarded LCMP development grant by Dept of Ecology ($50,000)