32 



Test results for the 152,920-cu-m (200,000-cu-yd), Plan 4 submerged berm 

 configuration revealed that, initially the berm appeared to diminish the wave 

 energy reaching the beach, which resulted in a decrease in the rate of erosion 

 along Camp EUis Beach, as opposed to that for existing conditions. The berm 

 material migrated toward, and actually fed, the beach. After continued expo- 

 sure to wave action, however, the berm eroded to a point where it provided no 

 wave protection and berm material along the beach eventually moved north. 

 Thus, the berm should be considered only a temporary solution to erosion at 

 Camp EUis Beach. 



Test results for the 76,460-cu-m (100,000-cu-yd) Plan 5 submerged berm 

 configuration revealed that the berm did not significantly diminish wave 

 energy reaching the shoreline. The rate of erosion along Camp Ellis Beach 

 was similar to that obtained for existing conditions. The berm material itself, 

 however, migrated toward, and fed, the beach. Additional wave exposure 

 resulted in the material along the beach moving north, and like Plan 4, the 

 Plan 5 submerged bemi should be considered only a temporary solution to 

 erosion at Camp EUis Beach. 



Results of wave height tests for the +3.0-m (-i-lO-ft) crest el, 914-m-long 

 (3,000-ft-long) spur of Plan 6 indicated reduced wave heights along Camp 

 EUis Beach when compared to those measured for existing conditions at the 

 -1-2.7-m (-1-8.8-ft) tide conditions (1.5 versus 2.7 m (4.8 versus 8.9 ft)). A com- 

 parison of sediment tracer patterns indicated that Plan 6 would significantly 

 reduce the rate of erosion of the beach; however, with continued exposure to 

 wave action, sediment along the beach would eventuaUy erode, moving north. 

 By raising the crest el of the spur to +4.6 m (+15 ft) (Plan 7), wave heights 

 were reduced to 1.2 m (3.9 ft) for similar condiUons with the +2.7-m (+8.8-ft) 

 swl. Current magnitudes adjacent to Camp EUis Beach for Plan 7 were 

 0.3 m/s (1.0 fps) as opposed to 0.9 m/s (3.1 ips) for existing conditions. Sedi- 

 ment tracer patterns for Plan 7 indicated that sediment wiU not move out of the 

 immediate vicinity of Camp EUis Beach for storm waves during normal high 

 water tidal conditions. Runup onto the overbank was reduced significanUy 

 with Plan 7 (versus existing conditions) for extreme wave and tide conditions; 

 therefore, the plan should result in less damage to the shoreUne for these 

 extreme occurrences. The reduction in length of the spur from 914 to 457 m 

 (3,000 to 1 ,500 ft) (Plan 8) resulted in wave heights along the beach increasing 

 to 2.3 m (7.5 ft) for +2.7-m (+8.8-ft) tide conditions; however, due to wave 

 diffraction around the spur head, waves tended to approach the beach from a 

 more northerly direction. Sediment tracer tests for Plan 8 indicated that mate- 

 rial along Camp EUis Beach in the lee of the spur wiU not be as stable as for 

 Plan 7, but it wiU not move out of the immediate area. Runup and current 

 patterns and magnitudes for Plan 8 were similar to those obtained for Plan 7. 

 The longer Plan 7 structure should provide wave and shoreline protection for a 

 longer reach of the beach (to the north) than Plan 8. 



Results of wave height tests along the beach with the north breakwater 

 removed (Plan 9) revealed that maximum wave heights were slightly, but not 

 significanUy, less than those obtained for existing conditions. However, 



Chapter 4 Tests and Results 



