All extensions of water mains outside of the city limits shall be made either by the water division at the expense of the owners of the property to be served thereby, or by the owners of said property under the supervision of the water division and in accordance with the plans and specifications therefor prepared by the water division, in which case the property owners shall pay to the water division in advance an amount equal to ten percent of the estimated cost of such extension to cover the cost of plans, specifications, supervision and overhead expense. (Ord. 97-16 § 32, 1997: Ord. B-606 § 45, 1944).