Figure 47. Void and steep slope at head of Cattaraugus Creek south 

 breakwater 



Manasquan Inlet Jetties, New Jersey 



Manasquan Inlet is located on the Atlantic coast of New Jersey approxi- 

 mately 42 km (26 miles) south of Sandy Hook and 37 km (23 miles) north 

 of Barnegat Inlet. The inlet provides the northernmost connection be- 

 tween the ocean and the New Jersey Intracoastal Waterway. Historical 

 records indicate the inlet has migrated, and even closed on occasion, prior 

 to jetty construction. Attempts to stabilize the inlet with timber jetties in 

 1883 and 1922 failed, leading to Congressional authorization of the pres- 

 ent project in 1930. The project entailed the construction of two rubble 

 jetties, with steel sheet-pile cores, spaced 122 m (400 ft) apart (Fig- 

 ure 48). The north jetty was 375 m (1,230 ft) long, and the south jetty 

 was 314 m (1,030 ft) long. Armor consisted of 1,814-kg (2-ton) capstone, 

 and the crest height of the jetties was +4.3 m (+14 ft) mean low water 

 (mlw). A 4.3-m-deep (14-ft-deep) mlw navigation channel was dredged 

 between the jetties. Through the 1970's the jetties were repeatedly dam- 

 aged by storms and structural settlement. Numerous repairs were at- 

 tempted, using armor stone of up to 10,890 kg (12 tons), without success. 

 The jetties were rehabilitated in 1982 using 14,515-kg (16-ton) reinforced 

 dolos armor units. On the south jetty, dolosse were placed on the outer 

 122 m (400 ft) of the north, or channel, side of the structure, around the 

 head, and along the outer 37 m (120 ft) of the south side of the structure. 

 On the north jetty, dolosse were placed along the outer 76 m (250 ft) of 

 the structure on its north side, around the head, and along the outer 28 m 

 (90 ft) on the channel side. Inshore of the dolos sections, the slopes were 

 armored with a single layer of 10,890-kg (12-ton) stones. 



42 



Chapter 2 Project Descriptions and Inspection Results 



