The procedure in this section must be used to improve an established and constructed drainage system.
In this section "improvement" means the tiling, enlarging, extending, straightening, or deepening of an established and constructed drainage system including construction of ditches to reline or replace tile and construction of tile to replace a ditch.
An improvement may only extend a drainage system downstream to a more adequate outlet and the extension may not exceed one mile.
(a) A petition must be signed by:
(1) at least 26 percent of the owners of the property affected by the proposed improvement;
(2) at least 26 percent of the owners of property that the proposed improvement passes over;
(3) the owners of at least 26 percent of the property area affected by the proposed improvement; or
(4) the owners of at least 26 percent of the property area that the proposed improvement passes over.
(b) The petition must be filed with the auditor or, for a drainage system in more than one county, with the auditor of the county having the largest area of property the improvement would be located on.
(c) The petition must:
(1) designate the drainage system proposed to be improved by number or another description that identifies the drainage system;
(2) state that the drainage system has insufficient capacity or needs enlarging or extending to furnish sufficient capacity or a better outlet;
(3) describe the starting point, general course, and terminus of any extension;
(4) describe the improvement, including the names and addresses of owners of the 40-acre tracts or government lots and property that the improvement passes over;
(5) state that the proposed improvement will be of public utility and promote the public health; and
(6) contain an agreement by the petitioners that they will pay all costs and expenses that may be incurred if the improvement proceedings are dismissed.
When a petition and the bond required by section 103E.202 are filed, the auditor shall present the petition to the board at its next meeting or, for a joint county drainage system, to the joint county drainage authority within ten days after the petition is filed. The drainage authority shall appoint an engineer to examine the drainage system and make an improvement report. The improvement proceedings must be conducted under this chapter as provided for the original proceedings for the establishment of a drainage project. The benefits and damages determined must be as a result of the proposed improvement. Assessments for the repair of the improvement must be based on the benefits determined for the improvement.
(a) If the existing drainage system needs repair and the petition for the improvement is for a separable part only of the existing drainage system, the engineer may include in the detailed survey report a statement showing the proportionate estimated cost of the proposed improvement required to repair the separable part of the existing system and the estimated proportionate cost of the added work required for the improvement. The notice of hearing on the detailed survey report must be given by publication and mailing to all persons owning property affected by the existing drainage system. The hearing may be held at the same time and location as the establishment hearing for the improvement.
(b) At the hearing, if the drainage authority determines that only a separable portion of the existing drainage system will be improved and that the portion needs repair, the drainage authority shall determine and assess, by order, the proportionate cost of the improvement that would be required to repair the separable portion of the drainage system to be improved. The order must direct that:
(1) the repair portion is allocated as repairs and assessed against all property benefited by the entire drainage system, as provided by section 103E.731; and
(2) the balance of the cost of the improvement is assessed in addition to the repair assessment against the property benefited by the improvement.