As an alternative to any other financing method, the Village Board may provide for the payment of the initial cost of any public improvement from the proceeds of special assessment "B" bonds issued under Sec. 66.0713(4), Wis. Stats. Special assessments to retire such bonds and pay the interest thereon shall be levied under Sec. 66.0713(4), Wis. Stats., payable in such installments at a rate to be determined by the Board based upon borrowed money rates at the time of the special assessment.