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https://hdl.handle.net/11681/37178| Title: | Environmental Assessment : West Onslow Beach and New River Inlet (Topsail Beach) and Surf City and North Topsail Beach Coastal Storm Damage Reduction Projects, Pender and Onslow Counties, North Carolina |
| Authors: | United States. Army. Corps of Engineers. Wilmington District. |
| Keywords: | Topsail Island (N.C.) Shore protection Storms Hurricanes Environmental protection Environmental management |
| Publisher: | United States. Army. Corps of Engineers. Wilmington District. |
| Abstract: | Topsail Island is a 26-mile long barrier island located in Pender and Onslow counties, NC. From south to north, the three communities on the island are the Towns of Topsail Beach, Surf City, and North Topsail Beach. In accordance with Congressional study authorizations, Coastal Storm Damage Reduction (CSDR) opportunities were evaluated for the entire island. A CSDR project for Topsail Beach was originally authorized as the West Onslow Beach and New River Inlet (Topsail Beach) project; a Post-Authorization Change (PAC) report (a General Reevaluation Report (GRR)) recommended a modification to the project as originally authorized. This modified project is near the end of the design phase of work and is currently awaiting reauthorization and appropriation of construction funds. A Feasibility Study for the Surf City and North Topsail Beach (SCNTB) CSDR project has been completed and the design effort for this project is also underway while awaiting authorization and appropriation of construction funds. The recommended plan for Topsail Beach is a dune (12 ft above National Geodetic Vertical Datum 29 (NGVD 29)) and berm (50 ft wide at 7 ft above NGVD 29) extending along approximately 26,200 ft of shoreline. The total required sediment volume for initial construction and nourishment events spanning the 50 year project life is approximately 13.6 Million Cubic Yards (MCY). The recommended plan for SCNTB consists of a dune (15 ft above NGVD) and berm (50 ft wide at 7 ft above NGVD 29) extending along approximately 52,150 ft of shoreline. The total required sediment volume for initial construction and nourishment events over the 50 year project life is approximately 32.3 MCY. Initial subsurface investigations were performed during feasibility phase analysis of both the Topsail Beach and SCNTB projects and included a total of 358 borings located offshore of Topsail Island, in Banks Channel behind the town of Topsail Beach, in the connecting channel between the Atlantic Intracoastal Waterway (AIWW) and New Topsail Inlet, and in New Topsail Inlet. A combination of boring data and geophysical surveys were used to identify and define borrow areas for both projects. Based on these initial Study phase investigations, a sufficient volume of compatible material was identified within 16 borrow areas located between 1-5 miles offshore of Topsail Island to meet the 50 year volume requirements for both projects. Compatibility evaluations at the time were completed in accordance with both the pending North Carolina state sediment compatibility standard as well as the Wilmington District’s sediment compatibility practice. |
| Description: | Environmental Assessment |
| Rights: | Approved for Public Release; Distribution is Unlimited |
| URI: | https://hdl.handle.net/11681/37178 |
| Size: | 56 pages / 2.97 MB |
| Types of Materials: | PDF/A |
| Appears in Collections: | Environmental Documents |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| EA_Topsail Beach and SCNTB_2013.pdf | 2.97 MB | Adobe PDF |  View/Open |