Authorizing and directing the revision of lines and grades on a portion of City Plan No. 42 by striking from the City Plan and vacating Thirtieth Street from Walnut Street (lower level) southwardly approximately six-hundred twenty feet to a dead end and reserving and placing on the City Plan a right-of-way for gas main purposes within the lines of Thirtieth Street being stricken from the City Plan, all under certain terms and conditions. — Open Common Ground