Haw. Rev. Stat. § 101-42: Rights-of-way.

Such corporations shall have the right to condemn rights-of-way over lands and property for ditches, tunnels, flumes and pipelines necessary or proper for the construction and maintenance of a system for conveying, distributing, and transmitting water for irrigation, fluming, mill use, generation of electricity, and domestic purposes; provided that no such corporation shall exercise the right of condemnation in more than one county.