Project Descriptions and 

 Inspection Results 



Nawiliwili Harbor Breakwater, Hawaii 



Nawiliwili Harbor is located on the southeast coast of the island of 

 Kauai approximately 185 km (115 miles) northwest of Honolulu, Oahu, 

 Hawaii. The harbor is protected by a 625-m-long (2,050-ft-long) rubble- 

 mound breakwater (Figure 2). The structure was originally constructed 

 with a single layer of keyed and fitted, 9,070-kg (10-ton) armor stone. 

 The structure has had a long history of repair since its original construc- 

 tion was completed in 1922. It has repeatedly been subjected to major 

 storm events, including three hurricanes, during its history. 



The first major rehabilitation of the structure in 1959 used 16,150-kg 

 (17.8-ton) tribar armor units. Two-layer, random placement was used on 

 the head and outer 15.2 m (50 ft) of the structure, and single-layer place- 

 ment was used along 152 m (500 ft) of trunk on the seaside slope. An- 

 other rehabilitation initiated in 1977 consisted of 9,980-kg (11-ton) dolos 

 armor units. Two layers of dolosse were placed from the toe to an eleva- 

 tion (el) of approximately +1.5 m (+5.0 ft) mean lower low water (mllw) 

 over the one-layer tribar trunk section. In addition, two layers of dolosse 

 were placed from the toe to the crest on the sea-side slope of the trunk for 

 a distance of 91 m (300 ft) shoreward of the tribar area. The structure 

 was again rehabilitated in 1987 with 20,865-kg (23-ton) dolosse. These 

 units were placed along the steepened head section below the water sur- 

 face and randomly in low areas around the existing head above the water 

 line. On the harbor-side slope, one layer of 5,900-kg (6.5-ton) tribars was 

 placed along a portion of deteriorated trunk. In addition, a 260-m-long 

 (850-ft-long) concrete rib cap was constructed to buttress the concrete ar- 

 mor units and stabilize the breakwater crown. 



Units of measurement in the text of this report are shown in SI (metric) units, fol- 

 lowed by non-SI (British) units in parentheses. 



Chapter 2 Project Descriptions and Inspection Results 



