To levy and collect taxes under class A as herein provided, the board shall in each year determine the amount of money necessary to be raised by taxation, taking into consideration other sources of revenue of the district, and shall fix a rate of levy which, when levied upon every $100 of assessed valuation of property within the district, and with other revenues, will raise the amount required by the district to supply funds for paying expenses of organization, for surveys and plans, paying the cost of construction, operating and maintaining the works of the district; but the rate shall not exceed 5 cents on $100, prior to the commencement of construction of the works, and thereafter shall not exceed 10 cents on $100, of assessed valuation of the property within the district. The board shall, between March 1 and March 15 of each year, certify to the board of county commissioners of each county within the district or having a portion of its territory within the district the rate so fixed with directions that at the time and in the manner required by law for levying of taxes for county purposes such board of county commissioners shall levy such tax upon the assessed valuation of all property within the district, in addition to such other taxes as may be levied by such board of county commissioners at the rate so fixed and determined.