Maintenance bonds. When required by the Commission to assure proper maintenance of all site improvements and structures, a maintenance bond in the amount of 10% of the cost of the site improvements shall be submitted to the city. The maintenance bond shall be in effect for a maximum period of one year from the date the improvements are accepted by the city. The bond shall be posted prior to the issuance of any additional zoning certificates of compliance. During such period, the applicant shall, when notified by the city, promptly and at his own expense, repair all failures and defects, including but not limited to the construction of roads, drainage, structures, appurtenances, bridges and other improvements as may occur during such maintenance period. He shall similarly repair all defects, settlements and irregularities of the structures and appurtenances of drains, pipes, mains, conduits, curbs, gutters, sidewalks, road surfacing, landscaping or other defective improvements detected during the maintenance period. If the applicant fails to remedy any such defects within 90 days of notification, the city may without prejudice to any other remedy cause the required repairs to be made and paid for with the proceeds of the maintenance bond.