The recommendations of the Nassau street mall improvement association concerning the proposed dissolution of the Nassau street mall special assessment district having been requested and considered by the city council in accordance with subdivision (a) of section 25-415 of chapter four of this title, therefore, pursuant to the authority granted by such subdivision, the Nassau street mall special assessment district is hereby dissolved as of the end of calendar day December 31, 1997, provided that as of such date there is no indebtedness, outstanding and unpaid, incurred to accomplish any of the purposes of the Nassau street mall special assessment district.