No filling, grading, clearing or development related to any structure or improvement, including stormwater management facilities, shall be permitted within any wetlands, active creeks, streams, watercourses, waters of the commonwealth, waters of the United States of America, wetlands buffers or riparian buffers. Upon proof that no reasonable engineering alternative exists, stormwater management facilities, utility crossings, public roads, private roads and driveway crossings may be permitted by conditional use. Any wetlands, active creeks, streams, watercourses, waters of the commonwealth, waters of the United States of America, wetlands buffers or riparian buffers permitted to be filled or otherwise destroyed by conditional use shall be replaced elsewhere on the site, in accordance with the applicable requirements of the Pennsylvania Department of Environmental Protection, so that the total predevelopment area shall not be reduced.