The bill establishes the Merrimack River Collaborative, a coordinating entity aimed at improving water quality in the Merrimack River and supporting biodiversity, climate resilience, and ecological health. The Collaborative will initially focus on the mainstem of the river, with potential future expansion to its tributaries. Its goals include convening members for collaborative projects, standardizing water quality monitoring, disseminating information on pollutants, prioritizing implementation projects, and identifying funding opportunities. The Collaborative will be managed by an Executive Committee composed of representatives from various organizations, including local governments and non-governmental organizations, and will have the authority to create special working groups as needed.

The Collaborative will not be a funded entity and members will not receive compensation for their services. It will conduct public hearings to gather testimony and data, and produce an annual report detailing its accomplishments and future efforts, which will be submitted to the clerks of the Senate and House of Representatives by December 31st each year. Appointments to the Collaborative must be confirmed by the Executive Committee within 90 days of the act's effective date, and the first meeting is required to occur within the same timeframe.