The road commissioners of a separate road district, by and with the consent of the board of supervisors evidenced by ordinance duly passed, may borrow money in a sum or sums not greater in the aggregate than two percent (2%) of the assessed valuation of the real and personal property within such district. Such loans shall be evidenced by the loan warrant or warrants of such district, signed by the road commissioners thereof and countersigned by the president of the board of supervisors, to bear not more than six percent (6%) interest per annum, and to run not more than five years from the issuance thereof. Provision shall be made at the time of making said loans for the payment thereof at maturity out of the roads funds for said district.