Haw. Rev. Stat. § 54-24: Operating expenses, reserves, and appropriations.

All receipts of the board of water supply other than from the sale of bonds shall be deposited daily in a bank by the board and the sums so deposited shall be accounted for and be paid into the county treasury at the end of each month and maintained in a special fund. The board may make appropriations and allowances from the fund for the following purposes:

(1) For the payment of the operating and maintenance expenses of the waterworks;

(2) For repairs, replacements, additions, and extensions;

(3) For accident reserve, pension charges, and compensation insurance;

(4) For payment of interest and sinking funds on all bonds issued for the acquisition or construction of the waterworks and extensions thereto and for the reserve fund.