Professional Engineer Joshua Robinson opposes permit application to fill Gadsden Creek

1934 aerial photograph showing Gadsden Creek area, Courtesy of the The Citadel’s Daniel Library and Gadsden Creek community group (click image to enlarge)

1934 aerial photograph showing Gadsden Creek area (on left), Courtesy of the The Citadel’s Daniel Library and Gadsden Creek community group (click image to enlarge)

Joshua L. Robinson, Professional Engineer, licensed in South Carolina submitted his letter concerning the destruction of Gadsden Creek by the WestEdge development project to Delete Apathy for publication. He is Founder & Principal, Robinson Design Engineers, 2008 to present, and received his MS, Civil & Environmental Engineering (Focus Group: Environmental Fluid Mechanics) from Georgia Tech, 2005 and BS, Civil & Environmental Engineering from The Citadel, 2003.

Subject: Permit Application Public Notice OCRM-15-103-J for Critical Area Fill

Mr. Slagel,

I am writing to strongly oppose the subject permit application. The proposed activities represent a perpetual adverse environmental impact, and the permit application does not provide any evidence whatsoever that reasonable safeguards have been employed to avoid this adverse environmental impact. South Carolina law defines critical areas as “coastal waters, tidelands, and beach/dune systems”. The permit application proposes to fill 4.025 acres of critical areas including Gadsden Creek and associated tidal tributaries and wetlands. Like most urban tidal systems along the South Carolina coast, the Gadsden Creek system has been historically altered and impacted. However, the existing ecosystem exhibits the defining characteristics of healthy, functioning coastal waters and tidelands including the following:

• Tidal flux and full diurnal hydrologic exchange with the Ashley River;
• Obligate wetland vegetation species typical of tidal marsh;
• Hydric soils typical of tidal channels and tidal marsh;
• A diverse, robust community of marine species of fish, birds, crustaceans, and mollusks.

These attributes are conclusive evidence that the 4.025 acres of critical areas are, in fact, coastal waters and tidelands protected by South Carolina law. The proposed activities would create an adverse, perpetual environmental impact that would completely and permanently destroy the existing tidal ecosystem.

Furthermore, the permit application does not describe any system of safeguards for avoiding or minimizing the adverse environmental impact. Instead, the permit application maximizes environmental impact by replacing the entire natural system with 2,220 feet of concrete culverts for stormwater drainage. The permit application does not outline any other alternatives to the proposed concrete culverts, nor does it explain why the impact is warranted. Clearly, other alternatives are feasible, and the adverse environmental impact could be avoided or minimized.

I am a professional engineer licensed in South Carolina. My areas of expertise are environmental and water resources engineering, and I have personally designed and overseen urban land development and drainage projects that protect and preserve on-site streams and wetlands. Furthermore, I have been personally involved in the restoration of urban streams and wetlands in Greenville, Columbia, and Sumter, SC; Charlotte and Asheville, NC; Knoxville, TN; and Atlanta, GA. I have first-hand knowledge of the technical and regulatory challenges associated with working near and within streams, wetlands, coastal waters, and tidelands.

It is my understanding that the proposed piping of Gadsden Creek has been designed to alleviate flooding and to encapsulate a historic landfill in the project area. Although these are challenging engineering problems, they are not unique and they do not warrant the permanent destruction of the critical area. Other typical due-diligence, safeguards, and feasible engineering alternatives could include the following:

• Sampling and testing the quality of surface waters and groundwater in the project area to determine if environmental hazards do exist;
• Constructing underground stormwater detention infrastructure elsewhere within the project area, outside of the critical area;
• Constructing sheet piles and bulkheads to enclose and segregate the critical area;
• Restoring the critical area by excavating existing landfill debris beneath and adjacent to the critical area and rebuilding the tidal creek and marsh system.

Based on my knowledge of this project and my experience with similar projects, I strongly oppose this permit application. The proposed work is an egregious and permanent environmental impact that could be avoided.

Sincerely,

Joshua L. Robinson, PE

SC PE No. 26831

You can take action to oppose the filling of Gadsden Creek by writing to DHEC. Public comments will be excepted until July 2nd, 2015. Please contact:
Matt Slagel
Wetland Section Project Manager
SC DHEC – Ocean and Coastal Resource Management
sl******@dh**.gov
1362 McMillan Ave., Suite 400
Charleston, SC 29405
P: (843) 953-0250 / F: (843) 953-0201

Andrew Wunderley of Charleston Waterkeeper, Katie Zimmerman of the Coastal Conservation League, and Gadsden Creek community group can keep you abreast of the situation.