Mass. Gen. Laws ch. 131, § 46: Measurement of ponds

Section 46. The department of environmental protection shall, upon the request and at the expense of any person claiming to be interested in a pond, cause a measurement thereof to be made which shall be recorded in the office of the clerk of each city and town within the limits of which any part of such pond is situated; and no arm or branch shall be included as a part of such pond unless such arm or branch is at least fifty feet in width and normally one foot in depth.