There is created for the city a separate fund to be known as “cumulative reserve fund for sewage disposal plant.” Into this fund there shall be paid, pursuant to the 1953 budget, the sum of five thousand dollars from surplus moneys in the current fund. Thereafter there shall be paid into the fund annually, if budgeted annually, the sum of five thousand dollars from any available surplus moneys in the current fund, it being the purpose of this chapter to provide a definite financing arrangement whereby the city may acquire a sewage disposal plant. If in any particular year after 1953 there shall be available a sum greater or lesser than five thousand dollars, then the city council shall, bearing in mind the purpose of this chapter, budget such greater or lesser sums as may be available for payment into this fund.