After adoption of the Official Map, or part thereof, all streets,
watercourses and public grounds on final, recorded subdivision and
land development plans which have been duly approved by the Board
of Commissioners shall be deemed amendments to the Official Map. Notwithstanding
any other terms of this chapter, no public hearing need be held, or
notice given if the amendment of the Official Map is the result of
the addition of a plan which has been duly approved by the Board of
Commissioners.