When the final plat has been approved by the Planning Commission and Council the original tracing shall be returned to the subdivider, for filing with the County Recorder after all necessary certifications are received. The final approval will be for a period of three years. More than three years can be granted at the discretion of the Planning Commission and Council. If the development is not started within three years, the final plat shall be reviewed again by the Planning Commission and Council for consistency with the Municipal Thoroughfare Plan and any other Municipal plans.