The Raccoon Island Marsh Creation Project was led by the Natural Resources Conservation Service in the Spring of 2013 to establish a larger breeding ground for pelicans. A dike was installed and material was dredged from the ocean to create the marsh.
This shoreline protection project utilized hydraulic dredging to install 4,620 feet of scour aprons and 400 feet of geotextile tubes bordering Raccoon Island. Infrastructure Alternatives, Inc. (IAI) was responsible for dredging, installation of the geotextile tubes and scour aprons.
The initial dike for the marsh creation was completed by Weeks Marine; sand was hydraulically dredged to create the dike, which surrounds the north end of Raccoon Island. IAI installed geotextile tubes 10 feet from the dike on the ocean floor utilizing an 8 inch electric submersible pump to fill the tubes. The tubes were intended to protect the dike from washing out, however the dredged material was fine grain sediment and did not allow the geotextile tubes to fill to the desired height. IAI was then able to successfully implement an alternative approach and installed scour aprons.
IAI maintained and repaired the dike as needed, installed 6 millimeter plastic over the dike and installed geotextile scour aprons. 4,620 feet of 50 feet wide scour aprons was placed on top of the dike. The scour apron acts reduces erosion of the dike by protecting it from the action of the waves.
Scope of Work
- Survey and stake work zones
- Construct geotextile tube header system
- Maintain dike structure with marsh buggy excavators
- Cover dike with 6 millimeter plastic
- Fill and install geotextile scour aprons
- Fill and install geotextile tubes
- Sew geotextile scour apron fabric together as they were deployed
- Decommission geotextile tube header system
- (4) Marsh Buggy Excavators
- (3) barges ranging from 80 feet to 120 feet long
- 18 ton crane
- 75 horse power diesel electric submersible pump equipped with a jet ring
- 200 kW generator
- 6” electric dry prime pump
- 4,620 linear feet of scour aprons
- 400 linear feet of geotextile tubes
Project Photo Gallery
- Breakwater extending out from the island
- Deploying a geotextile tube in the water along the breakwater
- Pump used to fill the geotextile tubes
- Filled geotextile tube
- Filled geotextile tube curving around the end of the breakwater
- Breakwater covered with scour apron