where they provide Httle or no protection and sediment will migrate 

 north; thus, the submerged berms would only be temporary solutions to 

 the erosion problem at Camp Ellis Beach. 



Of the spur jetty plans tested, the +4.6-m (+15-ft) crest elevation, 

 914-m-long (3,000-ft-long) structure of Plan 7 was most effective in 

 significantly reducing wave heights along Camp Ellis Beach. Both 

 Plan 7 and the -i-4.6-m (+15-ft) crest elevation, 457-m-long 

 (1,500-ft-long) structure of Plan 8 would be effective in preventing 

 erosion of the beach. For both plans, sediment would remain in the 

 immediate vicinity and not migrate in a northerly direction. The longer 

 Plan 7 spur jetty would provide a more stable shoreline and protect a 

 longer reach than the Plan 8 structure. 



Removal of the north breakwater (Plan 9) would not significantly 

 reduce wave heights, alter current patterns and magnitudes, or decrease 

 the erosion rate along Camp Ellis Beach. Since the north breakwater's 

 impact on hydrodynamics off Camp Ellis Beach is minimal, the 

 presence of the structure should result in insignificant changes in the 

 northerly migration of sediment along the beach. Breakwater removal 

 would, however, significantly increase wave heights in the navigation 

 channel. Test results also indicate that the 91-m^/s (3,200-cfs) Saco 

 River discharge would have no impact on the erosion rate along the 

 beach. 



Pre-breakwater conditions of 1866 indicated that the ebb shoal at the 

 river mouth would meander, forming offshore bars and building the 

 beach. These bars would severely hamper, if not stop, navigation. The 

 original +3.0-m (+10-ft) el breakwater constructed in 1873 resulted in 

 similar shoaling patterns, since sediment moved over and through the 

 structure. The raised +4.6-m (+15-ft) el breakwater, completed in 1897, 

 reduced navigation channel shoaling and resulted in offshore bar forma- 

 tions north of the structure and seaward of Camp Ellis Beach. All 

 conditions tested with the historical alternatives resulted in sediment 

 constantly moving north out of the Camp EUis Beach area, suggesting 

 eventual erosion without nourishment or replenishment of the Camp 

 Ellis Beach. 



36 



Chapter 5 Conclusions 



