Iowa Code Title IX. Local Government [Chs. 331-420] § 357.16. Second election

If the majority of the votes cast at the second election held pursuant to section 357.15 are in favor of the proposed improvement, the board of supervisors shall again advertise for bids in the manner provided under section 357.14. If the bids at the second letting will not necessitate raising the second preliminary assessment more than ten percent, the board may let the contract to the lowest responsible bidder.