intersected the Camp Ellis shoreline. Raising the structure was accomplished 

 by completing 274-m-long (900-ft-long) sections every 2 or 3 years. Construc- 

 tion began offshore and proceeded landward. During the period 1891-1894, a 

 1,372-m-long (4,500-ft-long) south jetty was constructed to help stabilize the 

 entrance channel. The jetty was constructed to an el of +1.7 m (+5.5 ft) 

 (termed a "half-tide" jetty since it was mostly underwater at half tide). In 

 19(X) the shoreward 277 m (910 ft) of the south jetty was raised to +3.35 m 

 (+11 ft). 



Construction of a 91-m (300- ft) seaward extension of the south jetty 

 (el +1.7 m (+5.5 ft)) was completed in 1912. Also, the 122-m (400-ft) spur 

 jetty off the north breakwater was constructed after a number of destructive 

 northeasterly storms threatened to flank the breakwater. In 1930 a 488-m-long 

 (1,600-ft-long) seaward extension of the north breakwater was completed, and 

 an additional 262-m-long (860-ft-long) extension was completed in 1938. 

 These extensions had crest els of +1.7 m (+5.5 ft). Total lengths of the north 

 breakwater and south jetty in 1938 were 2,030 and 1,463 m (6,660 and 

 4,800 ft), respectively. Side slopes of the stone structures were IV: IH. 



In 1968, the inshore 259 m (850 ft) of the north breakwater was raised to 

 +5.2 m (+17 ft), resurfaced, and tightened, presumably in response to wash- 

 over of sand into the navigation channel from Camp Ellis Beach during 

 storms, and to guard against a breach at the shoreward end of the structure. 

 Also, an additional 259-m (850-ft) portion of the south jetty (extending sea- 

 ward) was raised to +3.35 m (+11 ft) in 1969. Revetment work along the 

 shores on both sides of the river was completed to prevent flanking of the 

 structures. The stone revetment along the shore near and north of the north 

 breakwater was completed in 1970, and the revetment along the shore adjacent 

 to and south of the south jetty in 1971. 



Problem 



Erosion of the shoreline at Camp Ellis Beach has been a serious problem 

 for many years resulting in homes and stt-eets being lost. The area adjacent to 

 the breakwater (approximately 457 m (1,500 ft)) is experiencing erosion at a 

 rate of about 0.9 m/year (3 ft/year), and an adjacent area to the north (about 

 305 m (1,000 ft)) is receding at a rate of approximately 0.6 m/year (2 ft/year) 

 (USAED, New England 1992). These rates represent average values, and 

 actual erosion varies from year to year. The entire area lacks natural nourish- 

 ment material. Therefore, storm waves remove the material from the shoreline, 

 and there is no sediment available to renourish the beach. Without improve- 

 ments, it is assumed that erosion will continue as it has in the past with contin- 

 ued loss of private homes and public infrastructure. 



Many have attributed the erosion of the Camp Ellis Beach area to the con- 

 struction of, and modifications to, both the breakwater and jetty at tlie mouth 

 of the Saco River. Early studies did not support this conclusion. The last 

 study, however, indicated that construction of the structures at the river mouth 



Chapter 1 Introduction 



