The sums accumulated in the cumulative sewer reserve fund shall be used exclusively with respect to a system of sewerage in and for the city as defined in RCW 35.67.010 with respect to the construction, condemnation, purchase, acquisition, additions to, conduct and operation of sewerage systems and plants for the city within or without the corporate limits, as well as the repair, replacement, and extension of the sewerage systems and plants, together with the redemption of similar bonds issued in the future. [Code 1980 at § 12.08.040].