Mass. Gen. Laws ch. 21 § 9
The division shall be the agency of the commonwealth having administrative responsibility, according to criteria established by the commission, over programs provided for by the Watershed Protection and Flood Prevention Act 16 USC 1001 et seq. and shall carry out, maintain and operate any works of improvement authorized by said federal act and limited by section fourteen; provided that it shall not be an applicant for assistance under said federal act.
Any employee or agent of said division may, at any reasonable time, enter upon any premises while engaged in the performance of any duties required under sections nine to sixteen, inclusive. The division may negotiate with any property owners such terms, agreements or contracts as may be necessary or convenient in carrying out the duties required under sections nine to sixteen, inclusive.
The term "works of improvement" as used in this section and in sections twelve to fifteen, inclusive, shall mean any undertaking for (1) flood prevention, including structural and land treatment measures, or (2) conservation, development, utilization and disposal of water in watershed or subwatershed areas not exceeding two hundred and fifty thousand acres and including any single structure which provides more than twelve thousand five hundred acre feet of flood-water detention capacity and more than twenty-five thousand acre feet of total capacity. A number of such watersheds when they are component parts of a larger watershed may be planned together when the local sponsoring organizations so desire.
Mass. Gen. Laws ch. 21, § 9