Revenues of a nonprofit water company for any fiscal year in excess of the amount necessary:
(1) To defray expenses of the company and of the operation and maintenance of its facilities during such fiscal year;
(2) To pay interest and principal obligations of the company coming due in such fiscal year;
(3) To finance, or to provide a reserve for the financing of, the construction or acquisition by the company of additional facilities to the extent determined by the board of directors;
(4) To provide a reasonable reserve for working capital;
(5) To provide a reserve for the payment of indebtedness of the company maturing more than one year after the date of the incurrence of such indebtedness in an amount not less than the total of the interest and principal payments on such indebtedness that are required to be made during the next following fiscal year; and
(6) To provide a fund for education in the effective use of services made available by the company;