Section 81G. Sections eighty-one A to eighty-one J, inclusive, shall not abridge the powers of the city council or the selectmen or any other municipal officer in regard to public ways or parks in any manner except as provided therein, nor shall they authorize the taking of land or the laying out or construction of any way or park shown on a map or plan, or the alteration, relocation or discontinuance thereof, except in accordance with the laws governing the same; provided, that, after a city or town has adopted an official map under section eighty-one E, no public way shall be laid out, altered, relocated or discontinued if such laying out, alteration, relocation or discontinuance is not in accordance with such official map as it then appears, unless the proposed laying out, alteration, relocation or discontinuance has been referred to the planning board established under section eighty-one A, and such board has reported thereon, or has allowed forty-five days to elapse after such reference, without submitting its report. After a city or town has adopted an official map under section eighty-one E, no person shall open a way for public use, except as provided in the subdivision control law, unless the location of such way is in accordance with such official map as it then appears, or has been approved by the planning board under the provisions of this section, and in either case, the grading, surfacing and drainage of such way has been approved by such board. Nothing in said sections shall render a city or town liable for damages, except such as may be sustained by entry upon land and other acts under section eighty-one B, by reason of changes in an official map under section eighty-one F, or by reason of the establishment of exterior lines under section eighty-one J.