(a) The municipality shall, monthly or more frequently if necessary, deposit to the credit of the bond and interest redemption fund an amount of money from the gross income and revenue of the project sufficient to pay, when due, the principal of and interest on the bonds.
(b) The governing body of the municipality may deposit a reasonable amount to the credit of the bond and interest redemption fund in excess of the amount required to pay bonds maturing during the earlier years of maturities of the bonds to provide a reserve fund to prevent a deficiency in payment of bonds maturing in later years.