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Below is a false color image of Seabrook Island, where the colors on the image represent the data values — in this case, elevation. The term "false color" simply means that the image is not a photograph, and that you should use the colorbar on the image to interpret what the colors mean. Here there are two prominent sandbars at the mouth of North Edisto River. This is data that would be extremely difficult to capture using traditional surveying methods. You can make a similar image using the BeachMapper software application provided on the second volume of this CD-ROM set. For more information about the BeachMapper application, click here.
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Portable Document Format (PDF) maps have been created to show LIDAR data for South Carolina's beaches and islands. PDF maps will allow you to zoom in on the data and print the maps at better resolution. However, because of the intense density of the data, the PDF files will not draw properly from your browser. If you have Adobe Acrobat Reader® software installed on your computer, you can view the maps by navigating to the pdf/islands directory on this CD-ROM and double click on a file. A directory of maps is available in the readme.txt file. Adobe Acrobat Reader software has been provided on this CD-ROM.
To learn more about PDF documents and installing the software need to view them, click here.
Seabrook, a barrier island approximately 4 miles long, is adjacent to North Edisto Inlet and is separated from Kiawah Island to the north by Captain Sams Inlet. Development on the island is a mix of single- and multi-family structures. A 5,000-foot continuous section of shoreline along the North Edisto Inlet and Atlantic sides of the island is armored with rock revetments and seawalls. The entire island is classified as an inlet zone, the armored portion is considered stabilized while the remainder is an unstabilized inlet zone.
Development on Seabrook began in the 1970s following two studies that found the island accretional. However, shoreline change patterns have been very dynamic over the past 50 years, as Seabrook has experienced over 1,000 feet of erosion and accretion during this time. The studies examined only recent erosion trends neglecting long-term cycles and gave a false impression of the island's status. In 1990 the beach was renourished with 685,000 cubic yards (cy) of sediment from the north shoal of North Edisto Inlet. On the northeast end of the island, Captain Sams Inlet is periodically pushed into Seabrook as the spit on Kiawah grows southward. Eventually the spit would be breached naturally and sand would migrate onto Seabrook. In 1983 and 1996, Captain Sams Inlet was artificially relocated in order to speed the process and alleviate erosion pressures on Seabrook.
Beach profile surveys are conducted in the spring and fall at approximately 400 monitoring stations throughout the State of South Carolina. Various agencies participate in the beach profile collection, including The South Carolina Department of Health and Environmental Control (SCDHEC) Office of Ocean and Coastal Resource Management (OCRM), Coastal Carolina University, and the College of Charleston. The results of the surveys provide a snapshot of the beach face. Over time, these surveys can be compiled to determine if and how the profile of the beach is changing. Below is a map of the stations and a sample of the profiles that can be extracted from the data. The beach profile data compiled by OCRM is provided on the second volume of this CD-ROM set.
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| *South Carolina Department of
Health and Environmental Control Office of Ocean and Coastal Resource Management |
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For more information about South Carolina beach profiles see: South
Carolina's Annual State of the Beaches Report, April 1998,
SCDHEC OCRM, 1362 McMillian Ave. Suite 400, Charleston, SC 29405.
| Beach | Seabrook Island |
| Construction Dates | 1990 |
| Completion Date | 1990 |
| Volume of Sand (cy) | 685,000 cy |
| Unit Area Volume(cy/ft) | 117 cy/ft |
| Source of Sediment | North shoal of North Edisto Inlet; hydraulic dredge |
| Grain Size Characteristics Native Sediment/Fill | Native= 2.43 mm (avg median) 2.51 mm (mean) |
| Previous Nourishments | 1982: 70,000-75,000 cy using land based equipment; 1983: Capt. Sam's Inlet relocated (~$300,000), 250,000 cy ($1.25/cy); 1996: Capt. Sam's Inlet relocated, second time. |
| Length of project (Coverage) | 5,850 ft |
| % Sacrificial Fill | 20% immediate loss predicted |
| Total Cost | $1.66 M |
| Cost of Components | N/A |
| Cost per Unit ($/cy) | $2.43/cy |
| Funding | Private: Seabrook Property Owners Association (POA) |
| Significant Storms | No Data |
| Storm Results | No Data |
| Action Taken | No Data |
| Monitoring | Coastal Science and Engineering, Inc. 1983 - 1995 |
| Engineer and Contractor | Coastal Science and Engineering, Inc. |
| Projected/Actual Lifespan | 10 years/ by 1993 80% fill still within project area but below mid-tide line |
| Historic Erosion Rates | 1963 - 1970: +13 ft/yr south end 1970 - 1984: -18 ft/yr center 1963 - 1984: +10 north end |
| Beach Stabilization Structures | ~5,000 ft rock revetment installed 1974 -1979; 1982: 8,000 ft of rip rap added to shoreline |
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