Whenever any city, town, village, county, special road district, sewer district or drainage district or other improvement district by its charter or by the laws of this state applicable thereto is now or shall hereafter be empowered to construct any public improvement, such city, town, village, county or district shall have power to pay for the labor and materials or any portion of both or either out of its general revenue, and to accept, use, and apply in whole or in part payment for the same any grant from the state or the government of the United States or any agency of either, and such city, town, village, county or district shall have power to accept a grant or assistance of labor for such improvement or portion thereof furnished by those employed by any state or federal agency for making such improvement, subject to the conditions, if any, imposed by such agency of the state or federal government. The balance of the cost of such improvement not paid out by the general revenue of such city, town, village, county or district, or not paid out of any grant of funds, or not represented by the furnishing of labor and materials by the state or United States government or any agency thereof, shall be levied as a special tax against the same property and in the same proportion upon which the whole of the cost of such improvement would have been levied as now provided by the charter of any such city, town, village, county or district, or the present laws of this state applicable thereto, except for such payment or grant. The proceedings in each instance providing for the construction of such improvements from their initiation to the awarding of the contract to the successful bidder and the rights and privileges of citizens and of each property owner affected thereby shall be the same as that now provided by the charter and law governing such city, town, village, county or district where the entire cost of such improvement is to be paid for in special tax bills or special assessments against property; provided, however, that the plans, specifications and the estimate of cost for such improvement now required to be prepared and filed according to law shall specify what portion of the material and labor or either it is estimated will be assessed against benefitted property. In letting contracts pursuant to this section the awarding authority shall require bidders to separately state the amount bid on that portion of such improvement for which payment is to be made by special tax bills or benefit assessments. Where any portion of the labor and materials on any such improvement shall be furnished in kind by the state or the United States government or any bureau or agency thereof in lieu of a cash grant the proceedings shall so state and bids shall be required only for the balance of the labor and materials and the contract shall be awarded to the lowest and best bidder or lowest responsible bidder on the balance of said labor and materials.