Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 59, § 5E

The assessors of a city or town where land is acquired by such other city, town or district for water supply or sewage disposal or for a public airport shall, within one year after such acquisition, determine the average valuation of such land under section five D and certify the amount so determined to such other city, town or district. The mayor or selectmen, the commissioners or prudential committee of a district, or the division of watershed management of the metropolitan district commission or the Massachusetts Water Resources Authority, within six months after receipt of said certificate, may appeal from such determination to the appellate tax board; and upon the approval of said board shall determine the valuation in the manner provided in the preceding section, and section sixty-five, so far as applicable, shall govern such appeal.

If land within any city or town shall have been taken from it for said purposes, and for any one of the three years prior to the taking shall have been used for any public purpose, and for that reason no taxes have been collected thereon, the city or town and the board or officer having charge of the land so taken may within six years after such taking agree as to the value of the land upon which the annual payment is to be made as aforesaid from the time of the taking, and if they cannot agree the board or officer shall notify the city or town thereof, and thereupon the value shall be determined by the appellate tax board under said section sixty-five, and said notice shall be deemed to be the notice referred to in said section sixty-five. This section and section five D shall apply to property held for the purposes of the watershed system of said division and the waterworks system of said Authority, except property situated in Ashland, Boylston, Holden, Hopkinton, Sterling or West Boylston, but shall apply only to property acquired by a city, town or district, prior to January first, nineteen hundred and forty-six, including land or property acquired for water supply purposes prior to such date by the metropolitan district commission, or a predecessor entity thereof and comprising any or all of the watershed system of said division or waterworks system of said Authority pursuant to the provisions of the Massachusetts Water Resources Authority Act.