Upon the filing of the order calling for a detailed survey, the engineer shall prepare the complete set of plans, specifications and estimates of cost, and shall make a complete report in duplicate of the work and recommendations to the board or court, including therein all maps and profiles, and shall file the report with the auditor or court administrator. If the report is filed with the court administrator, a complete copy also shall be filed with the auditor of each county affected. After final acceptance of the system, the engineer shall make revisions of the plan, profiles and designs of structures to show the project as actually constructed on the original tracings, and shall file the revisions in duplicate with the auditor or court administrator. When more economical construction will result, the engineer may recommend that the work be divided into sections and let separately, and may recommend the time and manner in which the work or any section shall be done.