The proposed project consists of establishing a freshwater stream and wetland umbrella mitigation bank in the Santee River (HUC 03050112) and Black River (HUC 03040205) subbasins within the Middle Atlantic Coastal Plain Level III Ecoregion. The LUMB is located entirely within Williamsburg County and comprised of 4 individual parcels: Gamble Tract (1,621,1 acres), Longlands Tract (2,295.7 acres), Mt. Hope Tract (1,890.6 acres) and Stoney Run Tract (1,673.6 acres).
The 7,481-acre multi-parcel property would be a privately held commercial bank used to provide compensatory mitigation for unavoidable adverse impacts to Waters of the United States, including streams and wetlands, which result from activities authorized under Sections 401 and 404 of the Clean Water Act, and Section 10 of the Rivers and Harbors Act. The intent of the Sponsor, in the development of the umbrella mitigation bank, is to eliminate redundancy in administration and focus review resources on technical issues related to the development, implementation, and success of site-specific mitigation plans for potential mitigation bank sites under the LUMB.
The overall goal of the LUMB is to responsibly address over 30 years of anthropogenic impacts from land alteration and drainage on stream and wetland systems. The objectives are to restore a naturally functioning ecosystem that includes the restoration of stream channels, wetlands, natural hydrology, and vegetation as they existed prior to drainage alterations, or to the extent practical with current and future intended land use practices.
The Sponsor is proposing to add the Gamble Mitigation Site (33.485, Longitude: -79.917) as the first site under the LUMB. Evaluations were completed at a watershed-scale to capture the full extent of mitigation potential for the Gamble Mitigation Site. These evaluations resulted in the estimated opportunity for approximately 13,950 linear feet of stream mitigation practices, representing approximately 7,410 functional feet, and approximately 56.4 acres of potential wetland mitigation practices for the Gamble Mitigation Site. For each of the Gamble Mitigation Site stream reaches, restoration activities would focus on reconnecting the streams to their historic floodplain elevations through plugging and/or filling the stream reaches in the conservation easement whenever feasible. Wetland hydrology would be restored or enhanced by reconnecting the restored stream beds to an active wetland floodplain by filling and/or plugging the existing channel in the conservation easement to the extent practical to safely convey overland flow outside the proposed conservation easement.