Cape Carteret EWP DSR
Cape Carteret, North Carolina
LDSI, Inc. assisted Resource Institute, Natural Resource Conservation Service, NC Department of Transportation, and other federal and state agencies (FEMA, CAMA, USACE, DWR, DEQ, NCDA&CS, etc.) with disaster inspection of a stormwater device and surrounding drainage infrastructure located in Cape Carteret, NC. The failure was first noticed following Hurricane Florence which produced 24 inches of rainfall over the 4-day event within the Emerald Isle – Cape Carteret area as reported by NOAA. Based on NOAA Atlas-14 precipitation frequency estimates this event would exceed the 0.1% occurrence probability event (1,000-year storm). LDSI was asked to assist with the Disaster Survey Report (DSR), perform a site visit, preform preliminary feasibility survey, develop a feasibility design, and develop an opinion of probable cost. LDSI, Inc performed a site investigation and performed a planning level survey to estimate the amount of material that was removed during the hurricane.
- LDSI developed the following concepts within the feasibility design:
- Grading to establish the stormwater berm and stabilize the slopes.
- Removal of accumulated sediment within the tidal marsh to prevent excess sediment accumulating in downstream culvert.
- Repair of stormwater infrastructure that is leading to scour and undermining of transportation infrastructure.
- Establish hardened spillway to serve as an auxiliary spillway for other large rainfall events.
- Re-vegetation of the berm and disturbed areas to minimize erosion post repair.
- The design services were completed ahead of schedule and under budget.
Cape Carteret BMP assessment & feasibility study. LDSI completed the documents as required by the federal agencies to move the project from the planning level to the approve-appropriated level. The engineering services for this project were approximately $7,400 for DSR assistance. The estimated construction repair cost at the completion of the concept plans was approximately $52,000.
- Dec. 2018 – March 2019
- Disaster Response
- Government Program Compliance
- Watershed Analysis
- Drainage System Design