to severe damages from hurricanes and extreme extratropical storms (locally 

 called northeasters). The August 1933 hurricane and the March 1962 extra- 

 tropical storm (the Ash Wednesday storm) devastated this coastal area. Storm 

 damages included loss of the beach, destruction of the bulkhead and seawall 

 system, damage to buildings, and inshore flooding. In addition, there has 

 been a continuing problem with beach erosion. Since 1962 annual harbor dredg- 

 ing of Rudee Inlet and pumping operations to bypass the sand at Rudee Inlet, 

 and/or the trucking in of sand from other sources, has been sponsored by the 

 Federal, state, and city governments to maintain a beach width of approxi- 

 mately 100 ft and a crest el of +5.4 ft. 



4. Existing protection consists of a combination of various bulkheads 

 with crest els between 10 and 12 ft NGVD and nourished beach. In 1970 CENAO 

 completed a feasibility study which recommended construction of a sheet-pile 

 seawall with a concrete cap at el 15 and heavy stone at the base. By 1983, 

 results of the previous study had been reevaluated and incorporated into an 

 initial (Phase I) seawall design and beach erosion control concept. The sea- 

 wall was designed with guidance from the Shore Protection Manual (SPM) (1984) 

 which is based primarily on monochromatic wave theory. Adequate storm protec- 

 tion was to be provided by the seawall without sacrificing aesthetics of the 

 ocean view. 



5. The proposed project seawall has a crest el of 15.7 ft NGVD and will 

 extend from Rudee Inlet north to 57th Street. Beyond this point, a dune and 

 beach system will occupy the area from 57th Street north to 89th Street. The 

 recommended plan also calls for a 100-ft wide berm at el +5.4 ft NGVD from 

 Rudee Inlet to 89th Street (Figure 3). When built, the seawall project should 

 provide 54-year flood protection to the community (CENAO 1984). 



Purpose of the Model Study 



6. This model study was conducted to determine the adequacy of the pro- 

 posed seawall design and, if necessary, to investigate the effectiveness of 

 design modifications. The physical model study was one of a series of tasks 

 conducted by CERC to aid in the design of the detailed Beach Erosion Control 

 and Hurricane Protection Project for Virginia Beach. The specific purposes of 

 this 2-D physical model study were to: 



