use of refraction and diffraction analyses. Other siting factors are the 

 direction and magnitude of longshore transport, the harbor area required, the 

 character and depth of the bottom material in the proposed harbor, and the 

 available construction equipment and operating capability. Shore-connected 

 structures are usually built with shore-based equipment (see Sec. V,3 of this 

 chapter) . 



4. Effect on the Shoreline . 



The effect of a shore-connected breakwater on the shoreline is illustrated 

 in Figure 5-25. Like the jetty, the shore arm of the breakwater interposes a 

 total littoral barrier in the zone between the seaward end of the shore arm 

 and the limit of wave uprush until the impounding capacity of the structure is 

 reached and the natural bypassing of the littoral material is resumed. The 

 same accretion and erosion patterns that result from jetties also result from 

 the installation of this type of breakwater. The accretion, however, is not 

 limited to the shore arm; it eventually extends along the seaward face of the 

 shore arm, building a berm over which littoral material is transported to 

 form a large accretion area at the end of the structure in the less turbulent 

 waters of the harbor. This type of shoal creates an ideal condition for sand 

 bypassing. A pipeline dredge can lie in the relatively quiet waters behind 

 the shoal and transfer accumulated material to nourish the downdrift shore 

 (see Sec. V of this chapter). 



Direction of net longshore transport ■»■ Santa Barbara, California (1975) 

 Figure 5-25. Effects of shore-connected breakwater on shoreline. 



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