1. Petition may at any time after the final fixation of boundaries of a drainage improvement district be filed with the department asking that all or a part of the proposed drainage system be constructed. If the work desired is not shown on the plans filed or differs from that so shown or if the cost of the work shall have changed, the department shall on request of the association or of the executive committee thereof make plans of such work, estimate the cost thereof and make tentative determination of the lands on which the cost of such work should be apportioned, making suitable subdivision of parcels and the enhancements thereto, if necessary.

2. Such petition must be in writing, signed and acknowledged in the manner of a deed to be recorded, by a majority of the owners of the property to share in the cost of the work and representing at least half of the total of the drainage enhancements of such property as shown by the recorded statement of enhancements, with subdivision of parcels made as above. The petition shall specify what part or parts of the work it is desired shall be built and the estimated cost thereof as the department may have determined.

3. On receipt of such petition the department shall prepare a description of the proposed work and a special apportionment of the cost thereof, shall file such statement and apportionment and, after due notice, shall hold a hearing thereon. Thereafter the department shall determine as to whether or not it is to the public interest to proceed with the work. The department may approve or reject the application or modify it and, if necessary, return it for further signatures or require a new petition to be filed in lieu thereof.

4. If the application is approved the approving order shall fix the boundaries of the land on which the cost is to be apportioned and the apportionment of such cost in final form shall be attached thereto. Certified copies of the order and apportionment in final form shall be filed and notice of such filing given. Thereupon such order and apportionment may be reviewed as provided by section 15-0905 and in due course shall be recorded.