1. The district engineer shall let or offer to let the job or labor of constructing the working sections, as directed in the order of the county commission, announcing the terms upon and the time within which the work shall be done.

2. All successful bidders shall forthwith execute and deliver to the engineer a bond payable to the drainage district, in at least twenty percent of the amount of the bid, with sufficient like sureties, conditioned for the faithful performance of the work let, in the manner and within the time specified in the contract; the engineer shall, within fifteen days after the day bids are received, return all contracts and bonds to and file report of his proceedings in the premises, in the office of the county clerk.

3. The county commission shall approve or reject all contracts and bonds and cause to be spread upon its record an entry of its action thereon and give notice thereof to the contractors. All bonds and a duplicate of all contracts shall be filed in the office of the county clerk, and when approved they shall be recorded upon the drainage record. The county commission may, in its discretion, for good cause, extend the time specified in the contract for completing the construction of the ditch or other improvement, but such extension shall not be construed or deemed to have the effect of impairing the contract, or the contractor’s bond, or releasing the sureties thereon.

4. If the work provided for by any contract be not performed in the manner or within the time therein fixed, or within such additional time as may have been granted to the contractor, the county commission may, in the same manner as original contracts are let, relet such portion of such work as may not have been performed by the contractor; provided, that the contracts shall not be let a second time to the same person. The defaulting contractor shall be liable on his bond for all damages, costs and expenses occasioned by his default.