Moneys credited to such reserve funds may be used by the municipality for the construction, reconstruction, expansion, operation and maintenance of such sewerage system, or for the making of payments to the federal government under the provisions of P.L. 92-500, and such fund shall not be subject to the provisions of Kan. Stat. Ann. §§ 79-2925 to 79-2937, inclusive, and any acts amendatory thereof or supplemental thereto, except that in making the budgets of such municipality, the amounts credited to and the amount on hand in such reserve funds, and the amount expended therefrom, shall be included in the budgets for the information of the residents of such municipality. If the governing body of any municipality shall determine that all or any part of the moneys which have been transferred or paid to such reserve funds is not needed for the purposes for which so transferred or paid, said governing body by resolution may retransfer such amount not needed to the fund from which it was originally transferred, and such retransfer shall be budgeted and subject to the provisions of Kan. Stat. Ann. §§ 79-2925 to 79-2937, inclusive, and any acts amendatory thereof or supplemental thereto and shall only be used for sewerage system purposes.