Mass. Gen. Laws ch. 92A1/2, § 17: Eminent domain

Section 17. The department, on behalf of the commonwealth, may take by eminent domain under chapter 79, or acquire by purchase or otherwise, lands in fee, easements, rights and other property that it deems necessary or desirable for carrying out the powers and duties conferred upon it by this chapter relative to the construction, maintenance and operation of the watershed system.