2 4 6 -20 -10 1.0 2.0 



(m/yr) 



Averoge Erosion Role 



Figure 29. Average preconstruction and postconstruction erosion 

 rates for 28 kilometers of shoreline near the FRF. 



Because long time intervals tend to smooth the data, two different hori- 

 zontal scales were used in Figure 29. The 1940 to 1975 data show accretion or 

 stability near the FRF and erosion at the northern and southern ends of the 

 study area. Between 1977 and 1979, erosion predominated with only a few areas 

 showing accretion. Interestingly, the area with the most noticeable accretion 

 is located around Caffey's Inlet. The area just south of the pier appeared to 

 be stable, while peak erosion of 17.1 meters (56.1 feet) per year was found 

 183 meters (600 feet) north of the pier. 



3. Topography . 



A contour map of the FRF site is shown in Figure 30. The island is 680 

 meters (2,200 feet) wide at the FRF and is bordered on the sound side by 

 a brackish water marsh (described in Section VI, 6). The area is typified 

 by dunes which reach heights of more than 14 meters above MSL; the beach is 



56 



