How to maintain the long-term depth of your cove

By Zach Harkness
Shoreline Management Ranger, Hartwell Lake

We often receive questions from shoreline permit holders inquiring if they can protect their coves from silting-in when lake levels are down. During prolonged periods of drought, silting can reduce the long-term depth of coves.

Silting is the result of erosion of upland soils being deposited into the lake bed. You can reduce or prevent erosion by creating a physical barrier, such as vegetation or rock, to stabilize and hold the soil, and to absorb some of the energy of the wind or water. As the run-off makes contact with the barrier, the flows slow down and the suspended soils settle out before entering the lake bed.

If the erosion originates on private property, the owner can take any preventative measures they wish on their property prior to the run-off reaching public land and ultimately, the lake.

If the erosion originates on public land, the adjacent property owner must contact their area ranger and obtain permission to undertake erosion prevention measures in those areas. You will need an erosion control permit, (which is free), before you can begin work. Please do not dig, remove or add vegetation, or perform any construction, or remove structures on public land without first obtaining permission from the Corps of Engineers.

A Hartwell shoreline permit holder in Anderson County, S.C., constructed this retaining wall to prevent erosion and silting on the cove. For projects like this one, please contact the Hartwell Lake Office and obtain an erosion control permit from the Corps of Engineers. USACE photo.

A Hartwell shoreline permit holder in Anderson County, S.C., constructed this retaining wall to prevent erosion and silting on the cove. For projects like this one, please contact the Hartwell Lake Office and obtain an erosion control permit from the Corps of Engineers. USACE photo.

Authorized erosion control activities include bioengineering methods (the use of vegetation or construction materials to control erosion and stabilize soil); planting native trees or shrubs; or retaining walls or riprap to disburse the flow of water. Plans for erosion prevention, including the tools and types of materials to be used, must be approved by the Operations Project Manager and included as part of a consolidated Shoreline Use Permit.

We prefer methods that provide additional aquatic habitat, such as bioengineering methods. You can obtain a list of authorized plants and application forms for riprap and retaining walls from the Hartwell Office. We are happy to work with you to determine the best methods for your situation.

We also issue separate permits for “in the dry” dredging (when the lake bed is dry and exposed during drought), but you can only dredge silted material to reclaim the original water depth. Any dredging beyond the original depth (which was established when the lake was impounded) is strictly prohibited. If you’re considering dredging, please call your area ranger to coordinate a site visit to determine if the area is suitable to be dredged. For example, some areas of the lake have evolved into a wetland area with vegetation that thrives in shallow areas. These areas would not be considered for dredging.

Some unique designs, such as retaining walls and other structures, may require certification by a state licensed engineer. All shoreline protection activities that take place below the full pool elevation level (660 feet above mean sea level) are also subject to Section 10 of the Rivers and Harbors Act and/or Section 404 of the Clean Water Act. These additional authorizations would only be considered after a shoreline protection project is approved by the Operations Project Manager’s Office.

As a federal project and public resource, it’s our responsibility to ensure the long-term livelihood and biological integrity of the lake’s shoreline and surrounding public lands. For more information regarding shoreline management at Hartwell Lake, please contact the Hartwell Operations Project Manager’s Office toll free at 1-888-893-0678 or email us at CESAS-OP-H@usace.army.mil. For Thurmond Lake shoreline questions, please call the Thurmond Operation Project Manager’s Office toll free at 1-800-533-3478 or email CESAS-OP-T@usace.army.mil

About US Army Corps of Engineers Savannah District

The U.S. Army Corps of Engineers Savannah District oversees a multi-million dollar military construction program at 11 Army and Air Force installations in Georgia and North Carolina. We also manage water resources across the Coastal Georgia region, including maintenance dredging of the Savannah and Brunswick harbors; operation of three hydroelectric dams and reservoirs along the upper Savannah River; and administration of an extensive stream and wetland permitting and mitigation program within the state of Georgia. Follow us on Twitter @SavannahCorps and on Facebook.com/SavannahCorps
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