The Commission has the powers and duties: That are vested in it by Article III, § 40B of the Maryland Constitution, subject to and in accordance with the provisions of Subtitle 3, Parts III and IV of this title; and That otherwise are vested in it by law or delegated to it by the Administrator or the Secretary. Only the Commission may exercise the condemnation powers and duties vested in it by Article III, § 40B of the Maryland Constitution.