The Board of Directors of the Costa Mesa County Water District shall enforce the same or similar provisions as Ordinance No. 122 of the City of Costa Mesa, respecting extension of water mains and costs thereof and the requirement of annexation to the City of Costa Mesa for water service in the area formerly served by the city system and the contiguous area northerly and easterly thereof, until the full amount of the funds advanced or hereafter advanced by the city for mainline extension, reservoir or well purposes has been collected and refunded to the city.