Polk Swamp Restoration Project

Published April 14, 2015
Polk Swamp

Polk Swamp

The Polk Swamp aquatic ecosystem has been severely degraded by a substantial loss of bottomland hardwood forest habitat.  This degradation  is characterized by losses  of bottomland hardwood  trees, defined  stream channels,  the tree canopy  ( which provided shade and contributed  to diversity  of habitat types), an explosion of invasive  aquatic species, persistent flooding  of areas that were only occasionally inundated  in the past and a significant  increase in stagnant  water during non-flood periods.   The degradation has been attributed to the restriction of flow through the swamp’s stream channels caused by a large number of trees being blown down by Hurricane Hugo in 1989. The large number of downed trees in the channels slowed flow and overall drainage rates and persistently elevated water levels causing the remaining trees and canopy to die out.  These conditions then exposed the area to elevated sunlight, causing an explosion of invasive and nuisance aquatic vegetation, which further restricted flow within the remaining channels and further degraded the habitat and reduced diversity of both plant and animal species.  An estimated 205 acres of bottomland hardwood forest has died off.

Although minor, another factor affecting the swamp is an increase in beaver activity.  A 2011 investigation by the South Carolina Forestry Commission of Polk Swamp noted that the swamp has a very active beaver population and that the beavers were responsible for some of the tree mortality.  It is possible that the downed trees and subsequent change in hydrology and vegetation contributed to the increase in beaver activity.

The project area is located west of the Town of St. George in Dorchester County, SC.  St. George is located approximately 50 miles northwest of Charleston, SC.

The Polk Swamp feasibility study falls under the authority of Section 206, Aquatic Ecosystem Restoration, of the Water Resources Development Act (WRDA) of 1996 (P. L. 104-303), as amended.  Section 206 authorizes the Corps of Engineers to initiate investigations and implement projects for aquatic ecosystem restoration with the objective of restoring degraded ecosystem structure, function, and dynamic processes to a less degraded, more natural condition considering the ecosystem's natural integrity, productivity, stability, and biological diversity.

Dorchester County, South Carolina requested the U. S. Army Corps of Engineers, Charleston District’s assistance to address the serious degradation of the aquatic ecosystem in Polk Swamp, located west of the Town of St. George, about 50 miles northwest of Charleston, South Carolina.  Following a meeting with Dorchester County officials, and in a letter to the Charleston District dated December 1, 2010, the County expressed interest and intent in partnering with the Corps to complete a reclamation project “to restore the Polk Swamp ecosystem to a more natural condition”.   Subsequently, the Charleston District sent a response letter to the County dated December 13, 2010 which presented several options besides the CAP Section 206 program, including the CAP Section 208 authority for snagging and clearing and the Planning Assistance to States (PAS) program for studying various issues and coming up with solutions (but does not lead to construction).  In a letter to the Charleston District dated October 21, 2013, the County confirmed their interest and intent on a potential CAP Section 206 project, as well as their financial capability, starting in Fiscal Year 2014.

There is an informational public meeting on the feasibility study on Thursday, April 16th from 6:00 – 7:00 p.m. at the Kenneth F. Waggnor Services Center, County Council Chambers, 201 Johnston Street, St. George, SC 29477. For questions or comments, please contact Dudley Patrick at Dudley.Patrick@usace.army.mil