The City Engineer may grant a delay of the setting of required monuments or irons for a reasonable time, but not to exceed one year, on condition that the developer deposit with the City cash, a certified check, or an irrevocable bank letter of credit running to the City of Dexter, whichever the developer selects, in an amount as determined from time to time by resolution of the City Council. Such deposit shall be returned to the developer upon receipt of a certificate by a surveyor registered in the State of Michigan that the monuments and irons have been set as required, within the time specified. If the developer defaults, the City Council shall promptly require a registered surveyor to set the monuments and irons in the ground as shown on the condominium site plans, at a cost not to exceed the amount of the security deposit.