Wetland, Stream Bank, and Shoreline Restoration
Streambank & Shoreline Restoration in Tidal Environments: Creating Living Shorelines on Kiawah Island, South Carolina
Kiawah Island is renowned for its natural beauty and widely hailed as one of the most premier golf destinations along the east coast. Living along the coastal waters presents many challenges and residents are no strangers to tidal erosion. While large scale tropical storms and hurricanes, such as Hugo and Matthew have certainly played a role in erosive damage, erosion from high tide is a constant battle along inlets, canals and even the backwater ponds shorelines that intertwine the island.
While rising sea levels will play a larger role in erosion, the current challenges are likely more related to more frequency of high tide that is escalated by large storm events. The island is defined by designated “critical zones,” based on the amount of salinity in the water. Permitting for shoreline improvements in critical zones can only be obtained if the erosion is influenced by tidal conditions. Outside of the critical zone, many of the pond edges are experiencing erosion by a mixture of tidal influence, overland flow and frequent draw down for irrigation . Larger storm events continue to present challenges for the shorelines and canals. The saltwater/ freshwater mix and fluctuating water levels make it challenging to employ traditional erosion control and vegetative solutions.
KICA has developed sustainable standard practices to protect these valuable land and waterways. These practices focus on vegetative solutions that protect land, increase water quality and create natural habitat. In addition to these standards, many areas area being routinely surveyed to assess continual damage. While some projects may require integration of hard armoring solutions, the desired outcome is to create reinforced living shorelines. Prior to implementing these standards, residential erosion was approached with hard armoring, such as wood, stone and concrete walls. While these products typically solve erosion issues, they tend to be short lived and have a devastating effect on water quality, habitat and wildlife.
Through their collaboration, KICA has become a driving force of change in approach to living shorelines in South Carolina. KICA now plays a vital role in helping engage and empower residents through a mix of committees, newsletters and social media that focus on conservation and restoration.
The presentation will look at 2-3 case studies as recent successful examples. In addition to introducing the Envirolok system as a preferred solution, these case studies will explore other materials and living shoreline approaches used in conjunction with system in intertidal zones.
The first case study will include Kiawah Inlet Cove, which has been plagued by tidal erosion and stormwater runoff, eroding the banks onto residential properties. Tidal conditions and tight properties made access a challenge. Earlier efforts to slow the erosion, such as the use of oysters were met with mixed results. While looking for a working solution, KICA examined the importance of encapsulating the soil, while still providing ideal growing conditions for plantings within the tidal canal. This case study will detail the importance of how methods of vegetation and plant species were selected for this challenging corridor, as well as lessons learned in design, construction and maintenance.
The second case study will include a shoreline restoration project along backwater ponds. In addition to the aesthetic role along the golf course community, these ponds play a critical role in stormwater management and habitat. Because many of these ponds lie within the critical zone, permitting and approval is typically more restrictive. Restoration techniques require the ability to withstand tidal erosion and overland flow from adjacent residential properties. Wetland soils, limited accessibility and property owners’ desires to mow and maintain to the water’s edge presented additional challenges.