Idaho Code § 42-1301
When three (3) or more parties each own or possess and control land with appurtenant water rights which each are entitled to receive from the same point or points of delivery in a canal or reservoir, or from the same point or points of diversion from waters of the state, to be conveyed to their respective premises for any distance through the same lateral or distributing ditch or laterals or distributing ditches that are not operated and maintained by an irrigation district, canal company or other water delivery organization, such parties shall be members of and shall constitute a water users' association known as "Lateral Water Users' Association." Such water users' association may meet and organize at any time after thirty (30) days after this chapter shall take effect, and shall meet annually thereafter between January 1 and the last Monday in March of each year, at the call of the secretary of such association, said secretary to give ten (10) days' notice by mail of such annual meeting; provided that if for any reason the secretary should fail to call a meeting, then the annual meeting of such association shall be held on the last Monday in March of each year. At such annual meetings each water user shall be entitled to one (1) vote in person, for each inch and a fractional vote for each fraction of an inch of water which such water user is entitled to receive from such laterals, and a corporation shall vote by one (1) of its officers designated by it. Such association shall organize by the election of a chairman, vice-chairman and a secretary-treasurer, which officers shall also constitute the board of directors of such association, and shall hold office for one (1) year and until their successors are elected. Such association at the annual meeting shall also elect a manager of said lateral or laterals to be known as "lateral manager" for the succeeding season and shall fix the compensation of said manager, and of all officers. Such association may adopt such rules and regulations for the management of said lateral or laterals or distributing ditch or ditches and the delivery of water therefrom as they deem best, and may, by majority vote, if it be deemed for the best interests of the association, combine one (1) or more laterals and abandon laterals not in use, and do any and all things not in conflict with the provisions of this chapter or the laws of this state wherein the best interests of the association will be furthered.
Idaho Code § 42-1301