1. Hearings on the proposed establishment of a secondary road assessment district may be adjourned from time to time without loss of jurisdiction by the board. On final hearing the board shall proceed to a determination of the matters raised in the proposal. The board may reject, approve, or modify and approve said proposal. The board may exclude lands from the district or may add lands or otherwise modify the proposal.
 2. If the proposal is approved in whole or in part, the board shall establish the district. The order of the board establishing the district shall state the road or roads to be improved, the type of improvement, and the lands included in the district. The order shall be final and lands shall not be added to or excluded from the district after the order is entered by the board.