Whenever it shall be deemed necessary by the boards of flood irrigation of two or more counties in this state to construct or extend a project through or into two or more counties in the state, the several boards of flood irrigation in the counties into or through which such proposed project may extend when completed, are empowered to establish, construct, and maintain such project through or into two or more counties in the following manner:
1. There first shall be presented to the board of flood irrigation in each of such counties a petition for the establishment of such flood irrigation project in the several counties as provided by law, and the boards of the several counties shall determine upon the necessity or expediency of the establishment of such flood irrigation project as provided by law;2. The several boards of flood irrigation of the counties through or into which such proposed project may run then shall meet and agree upon the proportion of damages and benefits to accrue to the lands affected in each county, and for this purpose they shall consider the entire course and territory of such project in all said counties as one project;3. They may apportion the cost of establishing and constructing such entire project ratably and equitably upon the lands in each county in proportion to the benefits to accrue to such lands;4. When they have so apportioned the same they shall make a written report of such apportionment to the auditors of the several counties affected, and the report shall show the portion of the cost of such entire project to be paid by taxes upon the lands in each of such counties. Such report shall be signed by the boards of flood irrigation of all counties affected; and5. Upon the filing of such report, the board of flood irrigation of each county shall meet and assess against the lands in such county ratably and equitably as provided by law an amount sufficient to pay the proportion of the cost of such drain fixed for such county by all said boards.