that which the new beach will require. This will reduce starvation of down- 

 drift beaches. If a number of breakwaters or a long segmented structure is to 

 be built, construction should begin at the downdrift end of the project and 

 proceed updrift to promote a more spatially uniform accretion of the shore- 

 line. Constructing the most downdrift portion first reduces construction- 

 induced erosion of the project beach. 



65. Construction limitations may play a major role in determining the 

 water depth in which the breakwater is to be placed. There is a zone where 

 construction often is impractical without highly specialized equipment. Its 

 landward boundary is the maximum depth at which land-based machinery can oper- 

 ate (say 1 to 1 . 5 m) and its seaward boundary is defined by the draft of 

 floating construction vessels (say 2 to 3m). Wave activity and tidal range 

 greatly affect the boundaries of this zone. Most large-scale detached break- 

 water projects require sea-based construction. However, if wave activity 

 during construction will be slight, sand access roads to the breakwater loca- 

 tion can be constructed with fill material. In this way, land-based machinery 

 can work farther offshore than is normally accessible. The access roads 

 should be removed and/or the fill material redistributed along the shore after 

 construction, to prevent the project from functioning as a T-groin. This con- 

 struction procedure was employed at Colonial Beach. Conversely, floating 

 construction equipment can work closer to shore than normal by dredging a 

 channel to the nearshore. This technique was employed at Presque Isle. 



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