Upon receipt of the budget submitted by the commission, the county auditor shall levy taxes upon all the assessable property in the district to meet the expenses thereof as herein authorized and upon the collection of such taxes by the county treasurer, they shall be disbursed by the treasurer upon the approval of the commissioners of the district for the purposes herein stated. All taxes so levied for such special district shall be kept separate on the assessment roll from other levies and moneys so collected and shall be kept in a separate fund for such district and any surplus that may occur in any one year shall be carried forward and applied to the next year’s account and be properly considered in the budget for the expenses of such district for the ensuing year.