Haw. Rev. Stat. § 54-15

The board of water supply shall manage, control, and operate the waterworks of the county and all property thereof, for the purpose of supplying water to the public in the county, and shall collect, receive, expend, and account for all sums of money derived from the operation thereof and all other moneys provided for the use or benefit of the waterworks and all property used for or held in connection therewith.