The board of any district which has owned and operated a water distribution system for at least 10 years and which maintains a system of accounting substantially in accordance with the Uniform System of Accounts for Water Utilities prescribed by the Public Utilities Commission may provide, by resolution, under the terms and conditions as it sees fit, for the payment, without prior specific approval by the board, of demands against the district which relate to obligations incurred for purposes and within the amounts specified for those purposes in a projection of the district’s operations for a period of not longer than one year, if the demands are approved by the general manager. The projection shall be expressed in terms of the major groups of accounts in the uniform system of accounts and shall be incorporated in the resolution.