There is hereby created an agency known as the "Redevelopment Agency" under the authority of C.G.S. § 8-126, as amended. The Agency shall consist of electors resident within Middletown who shall be appointed by the Mayor with the approval of the Common Council. The Agency shall consist of 16 members. Those first appointed shall be designated to serve as follows: three shall serve for one year, three shall serve for two years, three shall serve for three years, three shall serve for four years, and four shall serve for five years, respectively, and thereafter members shall be appointed annually to serve for five years. Each member shall serve until his successor is appointed and has qualified, and any vacancy shall be filled for the unexpired term.