The following message was forwarded to us by Friends of the Lake:
The Pond and Lake Connection will be treating Lake Lillinonah on Tuesday, September 1, 2026, targeting the invasive hydrilla with the aquatic herbicide Tribune.
The treatment will be done throughout the lake where hydrilla has been identified by an aquatic biologist. The majority of the treatment will be north of poison ivy island to lovers leap, and the northern section of the Shepaug river. There are isolated patches of hydrilla from New Milford all the way to the dam. They will be targeted on a spot-treatment basis. Please see map below for more details on location(s).
There are no labeled restrictions for swimming, fishing, boating or water contact. In the treatment areas, irrigation can commence on 9/6, livestock water on 9/2 and drinking for consumption on 9/4. Please reach out to The Pond and Lake Connection if you have any questions.
Funding for this hydrilla treatment is provided by the Grants for the Control of Aquatic Invasive Species Program administered by the Connecticut Department of Energy and Environmental Protection (DEEP)