Approval of the preliminary plat by the planning commission shall be effective for a maximum period of one year after approval, unless upon application of the subdivider, the planning commission grants an extension. If the final plat has not been submitted within one year, or the approved extension period, the preliminary plan must be submitted to the planning commission for reconsideration. However, preliminary approval of a large tract shall not be voided; provided that the final plat of the first phase is submitted for final approval within the one year period. (Ord. 86-3, 3-11-1986)