Certain exemptions from locating the natural resources overlay zoning district and related natural features, resources, and areas. Where a proposed lot, improvement, or earth disturbance is located more than 250 feet from the potential Natural Resources Overlay Zoning District and/or natural features, resources, and areas within the related Steep Slope Protection Overlay, Stream Protection Overlay, Surface Water Overlay, and Wetland Protection Overlay and which involves a "lot add-on," "lot consolidation" or "revised subdivision" plan which no new lots, structures and public improvements are created, the Natural Resources Overlay Zoning District and the specific applicable natural features, resources, and areas within the related Steep Slope Protection Overlay, Stream Protection Overlay, Surface Water Overlay, and Wetland Protection Overlay do not need to be located or delineated as required within this section. In such cases, the overlay zoning district and/or natural features, resources, and areas shall be located using any existing available data, such as Cumberland County GIS data, USGS topographical maps, and similar sources. If a specific applicable natural feature, resource, and area, or associated overlay zoning district is located within the two-hundred-fifty-foot distance, the specific applicable natural feature, resource, and area and associated overlay zoning district shall be delineated on the plan, to the extent to which it is located on the property.