Haw. Rev. Stat. § 54-22

The county treasurer shall, when so directed by the board of water supply, sell such bonds as may be authorized for the acquisition, construction, replacement, extension, or completion of the waterworks; provided that the sale shall otherwise be conducted in accordance with the procedure specified by the law for the sale of the bonds. The proceeds from the sales shall be kept by the county treasurer in a separate fund to be used only for the purposes for which the bonds were sold.