The contractor shall be responsible for contacting and working with the owner of the particular utility involved to pinpoint exact locations during construction. The Town Clerk shall cooperate with the contractor in locating these features but failure to locate such utilities or property or failure to show on the plans shall not relieve the contractor for all damage to existing utilities at his own expense. Any delay or extra cost to the contractor caused by pipelines or other underground structures or obstructions not shown on the plans, or found in locations different from those indicated, shall not constitute a claim for extra work or additional payment of damages. Adequate provisions shall be made for maintaining the flow of sewers, drains and watercourses encountered during construction, and structures which may have been disturbed shall be satisfactorily restored upon completion of the work. If any existing utility is located so that it interferes with the work in either alignment or grade and has to be moved or otherwise modified or projected, such work shall be done by the contractor, and adjustment in payment will be made at a price agreed upon, in writing, before the work is started. (1976 Code § 12.04.090)