Massachusetts General Laws Part III. Courts, Judicial Officers and Proceedings in Civil Cases (Ch. 211-262) Ch. 253, § 8

If the jury finds that the plaintiff has suffered the injury complained of it shall assess the amount of damages sustained within three years last preceding the commencement of the action and to the date of their verdict, taking into consideration any damage caused by the dam to other land of the plaintiff as well as the damage caused thereby to the land overflowed reduced by any benefit caused thereby to the plaintiff's land.