CPE - Holly Beach, LA

Eighty-Five (85) Breakwaters are filled by sand found under mud

A 5.2 mile long, beach nourishment project, was constructed in Holly Beach, Louisiana using 1.75 million cubic yards of sand located in relict river channel on the inner shelf and overburden by a layer of modern marine mud (mixed silts and clays).

Finding sand for the project was no easy task. The offshore area has a surface sedimentology composed of predominantly fine sediments (silts and clays) covering paleo-river channels associated with lower stands of Sea Level. CPE geologists, geophysicists, engineers and oceanographers located beach compatible sands (0.1 to 0.15mm mean grain size with 4 to 20% percent silt) at a paleo channel located at about 4 to 7 miles offshore. The channel was covered by a layer of about 5-9 ft thick of fine silt and clay.

Weeks Marine, Inc. dredged fine sand from the relict river channel approximately four miles offshore of the beach. In order to access the sand 400,000 cubic yards of mud were dredged and placed in an opened water disposal area. To our knowledge this is the first time that sand in relict channels covered by mud (silts and clays) has been successfully explored for a beach nourishment project.

The sand was placed landward of the 85 segmented breakwaters and seaward of Highway 82. Highway 82 is a hurricane evacuation route and the sole direct connection between the ports of Cameron, LA and Port Arthur, TX. Project features included a 5 year storm- protective berm and 10 years of advanced nourishment.

Funding for the $12.4 million project was being provided from a combination of Coastal Wetland Protection and Restoration Act (CWPRA), Coastal Impact Assistance Program (CIAP), and a state environmental restoration fund.

The project was completed in March, 2003.

Holly Beach

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	Holly Beach, LA

	Eighty-Five (85) Breakwaters are filled by sand found under mud A 5.2 mile long, beach nourishment project, was constructed in Holly Beach, Louisiana using 1.75 million cubic yards of sand located in relict river channel on the inner shelf and overburden by a layer of modern marine mud (mixed silts and clays). Finding sand for the project was no easy task. The offshore area has a surface sedimentology composed of predominantly fine sediments (silts and clays) covering paleo-river channels associated with lower stands of Sea Level. CPE geologists, geophysicists, engineers and oceanographers located beach compatible sands (0.1 to 0.15mm mean grain size with 4 to 20% percent silt) at a paleo channel located at about 4 to 7 miles offshore. The channel was covered by a layer of about 5-9 ft thick of fine silt and clay. Weeks Marine, Inc. dredged fine sand from the relict river channel approximately four miles offshore of the beach. In order to access the sand 400,000 cubic yards of mud were dredged and placed in an opened water disposal area. To our knowledge this is the first time that sand in relict channels covered by mud (silts and clays) has been successfully explored for a beach nourishment project. The sand was placed landward of the 85 segmented breakwaters and seaward of Highway 82. Highway 82 is a hurricane evacuation route and the sole direct connection between the ports of Cameron, LA and Port Arthur, TX. Project features included a 5 year storm- protective berm and 10 years of advanced nourishment. Funding for the $12.4 million project was being provided from a combination of Coastal Wetland Protection and Restoration Act (CWPRA), Coastal Impact Assistance Program (CIAP), and a state environmental restoration fund. The project was completed in March, 2003. Top