Greeley Brook is one of four inlets feeding into Thompson Lake, located in the lake’s northwest corner. The brook flows directly into Pine Point Cove, an area that historically had the lake’s largest colonies of variable-leaf milfoil (VLM). The brook and the cove are separated by Route 26, with a roughly 30-foot gap in the land bridge allowing water to pass between.
In late 2025, Southern Maine Invasive Aquatic Management (SMIAM) conducted a targeted survey at the mouth of Greeley Brook and identified three well established VLM colonies growing in 4–6 feet of water. Each colony was estimated to cover about half an acre, surrounded primarily by dense native lily pads and grasses. There is no motorboat access to Greeley Brook.In September 2025, representatives from the Maine Department of Environmental Protection visited the site and strongly recommended that TLEA take action to control the milfoil in this area. These colonies have the potential to act as a source of new VLM fragments that could spread into Pine Point Cove and the broader lake.
TLEA has already removed over 10 acres of milfoil from the Pine Point area over the past 8 years. We feel taking a proactive approach to this infestation at Greeley Brook will be essential in reducing the regrowth of milfoil in this area, which could ultimately lead to fragmentation and migration of plants to the entire lake.
Proposed Treatment Plan
The goal is to cover all major dense milfoil colonies with benthic barriers during the 2026 season, then remove the barriers before fall.
Monitoring and Next Steps
