Wetland Mitigation Bank – Yadkin River Basin, North Carolina

The Louis Berger Group, Inc. (Berger) was selected by the North Carolina Department of Transportation (NCDOT) Project Development & Environmental Analysis Branch to identify, own, design, construct, plant and manage for five years the Second Creek and Homestead sites as part of the Louis Berger Wetland Mitigation Bank.  Berger developed the Bank through a Full Delivery Agreement with NCDOT to provide wetland mitigation within the Yadkin River Basin, Piedmont Physiographic Region. The NCDOT must frequently provide wetland, stream and other relevant mitigation to satisfy state and federal environmental laws and regulations. 

To meet these needs, Berger purchased 49 acres of floodplain at the Second Creek site and 35 acres at the Homestead site and restored the sites to functioning wetland and stream habitat through a design/build process.

The Second Creek site consisted of cropland located within the riparian corridor of Second Creek. The creek had been channelized over the past century, significantly reducing the wetland functions within the floodplain zones of the creek and making the site ideal for restoration and enhancement. Berger developed a concept plan for presentation before the Mitigation Banking Review Team (MBRT). Berger developed a detailed Mitigation Banking Instrument in cooperation with the regulatory resource agencies. The Banking Instrument documents and describes the goals, objectives, administration and management of the bank.  Berger developed the final construction plans including the Rosgen design of the geomorphological features of the restored stream. Today the site consists of 49 acres of restored wetlands and 3,000 feet of restored streams.

The Homestead site was ditched and converted for agriculture. The site is located on the floodplain of Third Creek, which has been channelized, further facilitating drainage of the site. These practices have significantly reduced the site’s ability to function as a riparian wetland, making it an excellent candidate for restoration work. All site investigations and design studies necessary to develop detailed mitigation plans were conducted by Berger. Investigations included geotechnical soil testing and assessment, analysis of soil and groundwater data, infiltration analysis of the site, and hydrogeologic analysis of the site. In addition, Berger developed existing and proposed Digital Terrain Models (DTMs) for use in topography design, volume calculations, and determination of habitat types.  The overall wetland restoration plan restored, enhanced and preserved the ecological functions associated with Piedmont Bottomland forested wetland communities.  Berger’s restoration plan also included the restoration of riparian buffers, removal of non-point sources of sediment and nutrients associated with agricultural operations, interception of stormwater runoff from adjacent up-slope developments and provision of a wildlife refuge.  Today the site consists of 35 acres of restored wetland and 2,500 feet of restored stream.

Berger's overall wetland restoration plan will aid in restoring, enhancing and preserving the ecological functions provided by ecosystems characterized as Piedmont Bottomland forested wetland communities, and Piedmont Levee Forest. Other wetland functions that are provided by Berger's restoration plan include the restoration of riparian buffers and wildlife corridors, floodwater retention and storage, removal of non-point sources of sediment and nutrients associated with agricultural operations, interception of stormwater runoff from adjacent up-slope developments, and provision of wildlife refuges and public viewing opportunities.  In addition, Berger conveyed the property to a non-profit conservation entity following the completion of construction and planting.

The project highlights Berger’s experience in the areas of wetland banking, wetland and stream design/build hydrological/hydraulic planning and engineering, environmental planning, stream restoration, investigative capabilities, and environmental restoration.