A comprehensive study of Onota Lake was completed in 1991 to identify causes of lake degradation and recommend mitigation strategies. The study identified excessive macrophyte growth as a primary problem of the lake. Since that study, Eurasian watermilfoil dramatically increased throughout both basins of the lake. The City partnered with LOPA to develop the Onota Lake Management Plan (1999) which documents short term and long term plans for both watershed and in-lake preservation actions. The primary goal of the restoration/management plan is to decrease nutrient and sediment loading through a comprehensive, well-coordinated watershed management program. Elements of the plan included the installation of a culvert at Thomas Island, nutrient rich sediment removal, continued volunteer monitoring, the identification and remediation of erosion problems, winter drawdown, the installation of stormwater best management practices, public education and outreach, and herbicide treatment. This plan has provided basic guidance in the management of the lake since then.
The City of Pittsfield, LOPA, and the Berkshire Regional Planning Commission (BRPC) have worked to implement several mitigation strategies. Due to the recreational importance of Onota Lake, the City determined that an intensive in-lake restoration and management program be implemented. Through such a program, immediate, user orientated improvements in lake quality could be realized.