Table 1 



Percentage of Dumped Material Transported 



into the Active Surf Zone in 1 Year 



Starting Month 11-ft Depth, percent 17-ft Depth, percent 



January 27.6 25.5 



April 27.3 25.5 



July 25.8 23.4 



October 28.8 24.8 



surf zone for the 11-ft depths than for the 17-ft depths. The quantity of 

 material transported into the active surf zone did not depend significantly on 

 the initial month of placement. During the tests, there was no noticeable 

 tendency for material to be transported to the nearshore region and remain 

 there permanently. Material was dispersed by the littoral currents when it 

 entered the nearshore region. This effect was noticed during the Currituck 

 experiment also. 



97. In addition to the extensive 1-year simulations, an overall 5-year 

 simulation was made to determine the volume rate of shoreward transport of an 

 initial 1-year dump of material over a consecutive 5-year time span. In this 

 simulation, a 1-year supply (1.45 million cu yd) of dredged material was 

 placed in a nearshore water depth of 17 ft. The results of this test, in 

 terms of percent of the initial volume moving into the surf zone each year, 

 were as follows: (a) 1st year — 25.5 percent; (b) 2nd year — 27.5 percent; 



(c) 3rd year — 26.5 percent; (d) 4th year — 18.8 percent; and (e) 5th year — 1.4 

 percent. From this analysis, SAW adopted an overall annual shoreward volume 

 rate of transport of 25 percent of a single year's volume of disposed material 

 and evaluated the shoreline response for this rate of material transport. SAW 

 found that this rate of onshore movement of dumped material was inadequate and 

 would result in severe erosion occurring along the northernmost 3 miles of Pea 

 Island. Accordingly, SAW recommended that no further consideration be given 

 to the DOI dredging/near shore disposal plan. 



98. SAW contracted with Coastal and Offshore Engineering Research, Inc. 

 (COER) to perform the same basic analyses described above, except an independ- 

 ent numerical model (Perlin and Dean 1983) developed by COER for CERC was 

 used. In the COER model the bathymetry was represented by n-contour lines, 



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