Lynches River Stream & Wetland Mitigation Site

South Carolina Department of Transportation
Lamar, Darlington County, South Carolina, USA

Preservation, Enhancement and Restoration

The South Carolina Department of Transportation (SCDOT) was required to procure substantial stream and wetland mitigation credits associated with five roadway projects in Florence County, South Carolina. HDR | ICA completed a site search to identify potential mitigation opportunities and is now working on the Lynches River Stream and Wetland Mitigation Site.

The site encompasses 800 acres and includes the restoration, enhancement and preservation of over 40,000 feet of the Lynches River, Rose Branch and several tributaries while also restoring, enhancing and preserving over 358 acres of wetlands within the Lynches River floodplain and bottomland hardwoods adjacent to tributaries.

Stream restoration practices included relocating Rose Branch to its historic valley (the existing channel had been routed to a separate valley), restoring two streams by removing and re-grading a lake and its associated dam and restoring a ditched and significantly incised channel that was flowing through an agricultural field. Wetland restoration and high-level enhancement were accomplished by removing two large impoundments within the Lynches River Floodplain which allowed for natural recharge and unimpeded down valley flood flows. Additional wetland enhancement included the filling of agricultural ditches within a modified wetland.

The site represents how we were able to successfully permit and construct SCDOT's most complex mitigation quandary to date. SCDOT had never successfully used one permittee responsible mitigation site to obtain roadway permit approval for multiple (5) roadway projects. By using one site for PRM for all 5 roadway projects, the state is saving millions of dollars and significant time. We met many times with regulatory agencies to explain how the site would meet all requirements of the 2008 Mitigation Rule and were required to complete substantial technical findings and reports to document in-kind mitigation. Ultimately we were able to obtain regulatory approval for the site and the associated roadway projects.

The site's mitigation plan was successfully implemented a couple years ago and is currently in the monitoring phase. 

  • Size: 800 Acres
  • Professional Services: Feasibility Report, Permitting
  • Project Type: Environmental, Remediation, Restoration, Wetlands