77. Where a highway corridor, a lakeshore or the bank of a permanent watercourse is used for the preservation of the buffer strip referred to in section 75 or 76, the buffer strips preserved on that shore or bank or along that highway corridor in accordance with sections 2 and 47 shall be widened, on the side opposite the side adjoining the road, watercourse or lake, to the width required under section 75 or 76.