Carter Stilley

American Mitigation Company, through its affiliate American Timberlands Company, developed and is managing one of the largest mitigation banks in South Carolina and the first mitigation bank to offer both wetland and stream restoration credits in the Coastal Plain of South Carolina. The bank was permitted in 2014 and serves Horry and Georgetown Counties. It is located on a 1,304 acre tract north of the Waccamaw River, directly abutting the South Carolina Department of Natural Resources (SCDNR) Waccamaw River Heritage Preserve. The Bank is approximately 1,085 acres, based on the proposed 150ft buffer around the wetland and stream resources that are protected by a conservation easement. 8,467 linear feet of stream and 426 acres of wetlands were enhanced or restored by the proposed restoration activities. An additional 279 acres of wetlands have been preserved.

Designing a coastal stream system presented unique challenges because they are naturally wide, shallow systems with a very low slope. Design efforts were initiated by assessing the site and collecting sufficient data (topographic, hydrologic, etc.) to evaluate existing site conditions and support development of construction documents and permitting. During the initial phases of this project, identification a reference reach was required to establish initial design metrics for the restored stream system. Two (2) reference reaches were identified in the coastal plain of South Carolina. A literature review of past projects was initiated to compile a data set that included more than two reference sites. This information was utilized to develop the design criteria, to verify the proposed monitoring plan and performance standards and to facilitate documentation of functional lift. Based on the metrics derived through this effort, a channel section, plan, and profile was developed to support restoration. The physical dimensions of the channel (section, plan and profile) were then further refined via analytical and computational methods in order to transpose the form based metrics to site specific solutions for the Carter Stilley tract.

Since construction was completed in 2015, personnel from American Mitigation Company have managed and conducted the Post Construction Monitoring and led IRT site visits to document success. As of 2022, the bank has received all of its monitoring period credit releases. Though the bank has been closed out, American Mitigation Company continues to manage credit sales for the Bank. The property title has been transferred to SCDNR as the long-term steward.