growth and seed germination by colonizing native plants along the bank . Each bag comes with two disk-shaped spikes made of high-impact polystyrene to keep bags in place . The spikes are easy to install and readily connect the system with other reinforcement strategies . Foundational materials are required to provide underlying support for the Envirolok system in the stream bed . Additionally , the top of the wall must be anchored to the bank using steel rods placed at regular intervals to provide support while plants begin to establish their own root systems .
The Envirolok system allows for a variety of vegetation application methods based on project budget , conditions on site , and desired appearance . The manufacturer suggests Hydroseed , plant plugs and live stakes as popular options for installing and establishing plants along the system . It is recommended to use native vegetation adapted to the local coastal environment . Plant materials should be selected based on conditions within nearby waterways and upland areas . Areas adjacent to tidal salt marsh or high salinity brackish ponds should consider placement of salt-tolerant wetland species . Typically , these include cordgrass , ( Spartina alterniflora ), salt hay ( Spartina patens ), sea ox-eye daisy ( Borrichia frutescens ), sweetgrass ( Muhlenbergia filipes ), and other plants commonly found along marsh edge habitats . Areas with lower salinities can utilize plants suitable for pond edge and wetland habitats . Due to the potential for storm surges and tidal inundation to occasionally affect coastal ponds and streams , it is recommended to use as least moderately salt tolerant plant materials on the lower portions of the walls . Site planning should incorporate the type of vegetation that is naturally present on site .
Utility lines should be identified prior to the design and preparation of the site . Property owners or contractors should contact # 811 to make a request for utility lines to be identified .
Installation
It should be noted that every site location will have specific requirements for Envirolok installation . There is no one design standard that can be applied to all potentially successful project locations . Figure 22 , on the following page is the adapted version of an approved design drawing prepared for one of KICA ’ s Envirolok Projects on Canvasback Pond . In this location a geotechnical engineer was required to be onsite prior to the wall construction to confirm soil types and design properties . This is required to ensure that all locations along the wall are capable of supporting the maximum applied bearing pressure without failure or excessive settlement . During this project , the following provisions were suggested by Envirolok for quality assurance :
1 . Wall construction shall be supervised by a qualified engineer or technician to verify field and site soil conditions . If this work is not performed by the site geotechnical engineer , a qualified geotechnical engineer / technician shall be consulted in those matters pertaining to the soil conditions and wall performance .
2 . The foundation soils at the base of the wall ( s ) shall be inspected by the geotechnical engineer . Any unsuitable soils or improperly compacted embankment material shall be removed and replaced as directed by the engineer prior to wall construction to provide adequate bearing capacity and minimize settlement .
3 . All wall excavation and retained soils shall be inspected for groundwater conditions . Any additional drainage provisions required in the field shall be incorporated into the wall construction as directed by the geotechnical engineer .
4 . Wall backfill material shall be tested and approved by the engineer , meeting the minimum requirements of the approved design plans or specification .
5 . All soil backfill shall be tested by the geotechnical engineer for moisture , density , and compaction periodically ( every 2 feet vertically , 100-200 feet C / C ) meeting the minimum requirements of the approved design plans or specifications .
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NATURE-BASED SOLUTIONS MANUAL FOR KIAWAH ISLAND