An authority shall be a public corporation or authority and no part of its net earnings remaining after payment of its expenses shall inure to the benefit of any individual, firm, or corporation, except that in the event the board shall determine that sufficient provision has been made for the full payment of the expenses, securities, and other obligations of the authority, then any portion, as determined by the board, of the net earnings of the authority thereafter accruing may, in the discretion of the board, be paid to one or more of its authorizing subdivisions.