Idaho Code § 61-124
The term "water system" when used in this act includes all reservoirs, tunnels, shafts, dams, dikes, headgates, pipes, flumes, canals, structures and appliances, and all other real estate, fixtures and personal property, owned, controlled, operated or managed in connection with or to facilitate the diversion, development, storage, supply, distribution, sale, furnishing, carriage, apportionment or measurement of water for power, irrigation, reclamation or manufacturing, or for municipal, domestic or other beneficial use for hire.
A water system which consists of a canal system, or irrigation project constructed pursuant to the act of congress known as the Carey act and the statutes of this state relating thereto, shall not be considered a public utility under the terms of this act, and neither such water system nor the corporation, company or association owning or managing the same shall be under the jurisdiction, control or regulation of the commission.
Idaho Code § 61-124