It is the intent of the Subdivision Control Law that any subdivision
plan filed with the Planning Board shall receive the approval of such
Board if said plan conforms to the recommendations of the Board of
Health and to the reasonable rules and regulations of the Planning
Board pertaining to subdivisions of land; provided, however, that
such Board may, when appropriate, waive, as provided for in § 81-R,
such portions of the rules and regulations as is deemed advisable
(MGL c. 41, § 81-m).