Keta Coastal Defence
An $85 million (USD) beach stabilization, reclamation, and flood control project was required to restore and stabilize a severely eroded portion of the Ghana coastline. A design-build project format was selected using Great Lakes Dredge and Dock Company as the Contractor and Baird providing design services.
Ghana, West Africa
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The design-build format tested assumptions from the design phase during construction, allowing the design to be modified and optimized. There was over 15M m3 of dredging and four design/construct components.
- Construction of an 8.3 km road/causeway, re-establishing a link lost to erosion
- Sea defense works to prevent erosion
- New flood control structure to provide relief from extreme flooding conditions
- 122 hectares of land reclamation
- Address severe sand deficit and erosion rates of from 2 to 7M m3 per year.
- Minimize downdrift impacts during groin construction.
- No baseline data on site conditions.
- Highly erodible sediments were present and exposed.
- Control the release of periodic floodwaters from the areas surrounding the lagoon to the ocean.
- Developed a system that allows sand to be retained, but also pass around to reach downdrift beaches.
- Beach nourishment and groin construction allowed sand to begin to bypass the groin field system.
- Developed and validated a wave hindcast to describe the site conditions.
- Protection was extended far enough to protect erodible lagoon sediments.
- Developed a flood control structure to address this issue and minimize erosion.