Haw. Rev. Stat. § 54-57: Construction, additions, extensions, increases, betterments, and improvements.

The board of water supply shall locate and determine the character and type of all construction and additions, extensions, increases, betterments, and improvements to waterworks and water systems, and shall determine the policy for the construction or the making of such additions, extensions, increases, betterments, and improvements out of public funds under its jurisdiction.