Any nonconforming structure which is located less than the required setback from a water body, tributary stream, or wetland and which is removed, or damaged or destroyed, regardless of the cause, by more than 50% of the market value of the structure before such damage, destruction or removal, may be reconstructed or replaced, provided that a permit is obtained within 18 months of the date of said damage, destruction, or removal, and provided that such reconstruction or replacement is in compliance with the water body, tributary stream or wetland setback, requirement to the greatest practical extent as determined by the Planning Board or its designee in accordance with the purposes of this chapter. In no case shall a structure be reconstructed or replaced so as to increase its nonconformity. If the reconstructed or replacement structure is less than the required setback it shall not be any larger than the original structure, except as allowed pursuant to § 478-12C(1) above, as determined by the nonconforming footprint of the reconstructed or replaced structure at its new location. If the total amount of footprint of the original structure can be relocated or reconstructed beyond the required setback area, no portion of the relocated or reconstructed structure shall be replaced or constructed at less than the setback requirement for a new structure. When it is necessary to remove vegetation in order to replace or reconstruct a structure, vegetation shall be replanted in accordance with § 478-12C(3) above.