Authorizing the revision of lines and grades on a portion of City Plan No. 161 by striking from the City Plan and vacating a triangular shaped portion of the southerly side of Lancaster avenue from Fifty-sixth street to a point approximately three hundred ninety-one (391) feet westwardly therefrom, and by reserving and placing on the City Plan a certain right-of-way for drainage purposes, water main purposes and gas main purposes, and by placing on the City Plan a certain right-of-way for drainage purposes, under certain terms and conditions. — Open Common Ground