As soon as conveniently possible after organization, the board of commissioners of any drainage district shall appoint a competent civil engineer as chief engineer who shall engage assistants as the board of commissioners may approve.  The chief engineer shall have control of the engineering work in the district.  He may, by and with the consent of the board of commissioners, consult any eminent engineer or engineers and obtain his or their opinion and advice concerning the reclamation of lands in the district.  The chief engineer shall make all necessary surveys of the lands within the boundaries of the district that will be improved or reclaimed in part or in whole by any system of drainage or levees that may be outlined and adopted.  The engineer shall make a report in writing to the board of commissioners with maps and profiles of the surveys.  This report shall make recommendations as to any sub-district which should be created by the drainage district, and shall contain a complete plan for leveeing, draining, and reclaiming the lands from overflow of or damage by water, with an estimate of the total cost thereof.  The maps and profiles shall also indicate, so far as necessary, the physical characteristics of the lands and the location of any public roads, railroads and other rights of way, roadways, and other property or improvements located on the lands.  The map shall show the lands divided into forty acre tracts, or other small sub-divisions according to ownership.  The plan for leveeing, drainage, and reclaiming the lands shall take into consideration any sub-drainage districts that have been or should, in the opinion of the engineer, be formed in the drainage district.  If there are any existing sub-drainage districts, the engineer shall present in his report his recommendations as to whether the existing sub-drainage district, or sub-drainage districts, should be reclaimed separately or consolidated with other lands in the drainage district in one plan of reclamation.  Should he recommend the formation of a sub-drainage district, or sub-drainage districts, or should he recommend that any existing sub-drainage district, or sub-drainage districts, be reclaimed separately, he shall then make a similar complete plan or plans for the reclamation of the sub-drainage district, with complete maps, profiles, costs, etc., as in the case of the entire drainage district.  The chief engineer shall make a report in writing to the board of commissioners once every twelve months, and oftener if the board shall so require.  Upon receipt of the final report of the engineer concerning surveys made of lands contained in the district or sub-districts, if any, and plans for reclaiming the same, the board of commissioners may adopt the report or any modification thereof approved by the chief engineer after consulting with him or some one representing him, and thereafter the adopted report shall be the plan for leveeing, draining, and reclaiming the lands from overflow or damage by water.  After adoption it shall be known and designated as the plan for reclamation.  The plan shall be filed with the secretary of the board of commissioners and by him copied into the records of the district.