569.8. The reserve is made up of(1) any revenues from the tax under section 569.11 which are of right allocated to the reserve;
(2) the sums the municipality annually allocates to the reserve out of its general fund or its revenues from(a) any tax, other than the tax under section 569.11, or any tariff, if the tax or tariff is imposed either for the supply of water or for roads;
(b) any subsidy or other liberality not reserved for a purpose other than the purposes for which the reserve is created;
(3) the interest earned on the capital allocated to the reserve under subparagraph 1 or 2.