Mass. Gen. Laws ch. 21 § 9A
The division may, subject to the approval of the water resources commission and after proper consideration of the criteria established by the water resources commission, acquire by purchase, gift, lease, eminent domain, or otherwise lands and waters and easements therein to protect and conserve water impoundment sites and land adjacent to such sites which it deems necessary to meet the water resource needs of the commonwealth for flood control, low flow augmentation, and municipal water supply, provided that the exercise of the power of eminent domain shall be subject to the approval of the board of selectmen in a town or the city council in a city in which the land is located. If such board or council fails to approve or disapprove such proposed taking within ninety days after receipt of written notice of the proposed taking from the division, such board or council shall be deemed to have approved the same. No subsequent transfer or sale of such lands or waters by the division to any agency of the commonwealth or to any city, town, or district shall be made and no construction or water resources improvement thereon shall be undertaken without the approval of the general court. The division may enter into an agreement for the temporary supervision and maintenance of such lands and waters with any appropriate public agency, and may permit temporary compatible private uses subject to such conditions as it may impose. Said lands shall be subject to payments in lieu of taxes as provided in sections thirteen to seventeen, inclusive, of chapter fifty-eight. The division of water resources and its duly authorized agents, without being liable for trespass, shall have the right after giving due notice, accompanied by a detailed plan to enter upon any lands for the purpose of making surveys, test pits, borings and geologic investigation. Any damages to property resulting by the exercise of the aforementioned rights shall be reimbursed by the division to the owner of the property so damaged.
The water resources commission may also reimburse a city, town or district for acquisition costs of lands, waters and easements necessary for the development and protection of water impoundments for a regional municipal water supply system, provided that said regional water supply system meets criteria which may be established by the water resources commission. For purposes of this section, a regional municipal water supply system shall consist of two or more municipalities.
In the event that said city, town or district does not begin said regional water supply system project as authorized by law within a number of years to be determined by said commission, then said city, town or district receiving such reimbursement shall repay all monies at the prevailing interest rates to the commonwealth.
When an impoundment site is acquired under the provisions of this section which has the capacity for future development to meet substantially more than the needs of the cities, towns or districts served by the initial regional water supply system, provisions shall be included in the agreement with the water resources commission and in the agreement forming the district which will preserve the opportunity for other cities, towns or districts to later join the district and to share the impounded waters after having participated in the cost of the reservoir enlargement. The water resources commission shall enter into an agreement under this section to facilitate development of a water system to serve the original district and to preserve the opportunity for future expansion of said district.
Mass. Gen. Laws ch. 21, § 9A