Idaho Code § 43-1401
Whenever the boards of directors of any two (2) or more irrigation districts which are contiguous deem it for the best interests of their respective districts that the same be consolidated into a single district, such boards of directors may petition the board of county commissioners for an order for an election, to vote upon the question of such consolidation, which petition shall state in detail the terms upon which such consolidation is proposed to be made: provided, however, when any two (2) irrigation districts which are contiguous, where one (1) district does not embrace more than one-tenth (1/10) the land in the larger district, and the board of directors deem it for the best interests of the respective districts that the same be consolidated into a single district, the board of directors may arrange by contract upon what terms and conditions the smaller district may be consolidated with the larger district, with the name and officers of the larger district still retained, which contract shall be submitted to the board of directors of the smaller district, together with the question of whether or not said districts shall be consolidated under the terms of the agreement, at a special election held for that purpose in such smaller district. Notice of such election shall be published as required for notices of election for indebtedness. At such election should two-thirds (2/3) of the electors voting, vote in favor of said contract and the consolidation of said districts, the board of directors of the smaller district shall petition the board of directors of the larger district, which notice shall be published in a newspaper published within the county wherein the office of the board of directors of the larger district is situated, for such length of time and covering the same matters as required by a petition of a private owner of land to have same included within the boundaries of an irrigation district. The law applicable to the inclusion of land within the boundaries of an irrigation district, after the petition is filed and notice given, shall apply to the consolidating, including and annexing of a smaller district in and to the boundaries of a larger district. After the board of directors of the larger district has made the order including said smaller district within the boundaries of the larger district, the board of directors of the larger district shall file a petition in the district court within the county wherein the principal office of the larger district is situated, asking for an approval and confirmation of the proceedings thereunder, and the same procedure shall be followed as provided by sections 43-406, 43-407, and 43-408 [, Idaho Code,] with reference to the confirmation of the proceedings within irrigation districts. In such petition the prayer shall be that the proceedings, together with the contract, may be examined and approved by the court; that after the confirmation of said proceedings the order of the board of directors admitting the smaller district into the larger district, containing a description of all the land properly certified by the secretary of the district, shall be filed for record in the office of the recorder of the county within which said land lies.
Idaho Code § 43-1401