The township board of each township availing itself of the provisions of this Article shall maintain a proper system of accounts showing the receipts from the operation of the system and the application of those receipts and shall at least once each year cause the accounts to be properly audited by independent public accountants. Copies of the audits shall be filed in the office of the township clerk and shall be made available for inspection at all proper times by any water user, township board member, or other interested person.