Any municipality having valid outstanding special assessment warrants or bonds issued pursuant to this title which are due, or to become due within one year, in whole or in part as to principal or interest or both or which are redeemable either at the option of the municipality or with the consent of the warrantholders or bondholders may issue refunding special assessment warrants or bonds if there is not sufficient money in the special improvement fund against which such warrants or bonds are drawn to pay the principal or interest or both or if a deficiency is likely to occur in the fund within one year for payment of principal or interest thereon. Such refunding special assessment warrants or bonds may be issued for any of the following purposes:

1.    To extend the maturities of the special assessment warrants or bonds.

2.    To reduce the rate of interest on the special assessment warrants or bonds.

    3.    To equalize the general tax which the municipality may be, or may become, obligated to levy to discharge deficiencies in the fund against which the special assessment warrants or bonds are drawn.

4.    To consolidate two or more outstanding issues of warrants or bonds.