All driveway aprons constructed or reconstructed over, across or upon any public right-of-way in the city shall be kept and maintained at all times in accordance with the provisions of this chapter by the owners and/or users of said driveway aprons. The only exception being that in those cases where the city requires installation of thaw pipes, the actual cost of thawing operations will be borne by the city. (Prior code § 14.15.060)