shore, facilities are being provided to trap the sand 

 before it reaches the canyons and transport it 

 mechanically to a point where it can resume 

 normal beach movement. Planting dunes with 

 appropriate grasses and shrubs reduces windbome 

 losses and aids in preservation. 



The Corps of Engineers has been authorized by 

 Congress' to conduct a National Study of Shore- 

 line Erosion. This will be a three-year study 

 dealing with the overall problems of beach erosion 

 and including advisory services to State and local 

 activities. 



The Corps also proposes to expand a program 

 initiated in 1964 to determine if large deposits of 

 suitable fill material exist in the offshore zone. 

 The program involves the accumulation of data on 

 the characteristics of material composing the 

 bottom and sub-bottom between the 15 foot and 

 100 foot depth contours. 



Since 1964 sand inventories have been com- 

 pleted along the New Jersey and Florida coast- 

 lines. Preliminary analysis of data indicates many 

 large deposits of suitable material in the offshore 

 zone. For example, about 600 million cubic yards 

 of suitable material are off the Florida coastline 

 and about 1.5 biUion cubic yards along the New 

 Jersey coastline, at distances ranging from one to 

 six miles offshore. 



Data have recently been collected along the 

 New England coastline and the area from Cape 

 Charles, Virginia, to the North Carolina line. The 

 remainder of the Atlantic and the Gulf, Pacific, 

 and Great Lakes offshore sand deposits are pro- 

 posed for study in future years as required. The 

 present problem is to develop the best method of 

 placing offshore deposits on the eroded beaches 

 and additionally provide a better means of creating 

 artificial islands and providing harbor channels. We 

 have much to learn about beach erosion and shore 

 protection and not all our past efforts in this area 

 have been successful. 



Available methods of shore protection are of 

 two general types. The first consists of interposing 

 structures to prevent waves from reaching erodible 

 material, such as offshore breakwaters, seawalls, 

 bulkheads, and revetments. The second consists 

 generally of stabilizing or restoring a beach by 



'River and Harbor Act of 1968, Public Law 90-483, 

 82 Stat. 731, Aug. 13, 1968 (formerly S. 1262 of the 

 90th Congress). 



reducing the rate of loss or increasing the rate of 

 supply or a combination of the two. The loss rate 

 may be reduced by means of impermeable groins 

 or jetties, or it may be compensated for by 

 periodic "nourishment" by adding sand on the 

 beach. 



The most suitable method depends upon char- 

 acteristics of a particular area. A beach is the most 

 effective absorber of wave energy. Therefore, a 

 protective beach is frequently the most suitable 

 measure. However, it is often not feasible to retain 

 a beach on headlands or exposed shores, and a 

 type of armoring of the shore must be used. 

 Protection of a short individual property on an 

 eroding shore is uneconomical, as the adjacent 

 shores will continue to recede and the protection 

 will be outflanked. 



Early efforts at shore protection used groins. 

 However, since sand moves along shore, groins 

 which can abstract normal sand movement along 

 the beach often cause erosion of adjacent shores 

 farther in the direction of along-shore transport. 

 Examples of failure to obtain satisfactory results 

 by use of groins alone can be found in New Jersey, 

 Palm Beach and Miami Beach, Florida, and the 

 Presque Isle Peninsula, Pennsylvania. 



Typical of present methods of protection is the 

 Wrightsville Beach, North Carolina project, which 

 combines beach erosion and hurricane protection. 

 Wrightsville Beach is a small island off the 

 souteast coast of the State, about 10 miles east of 

 Wilmington. It is separated from other portions of 

 the barrier beach by Moore Inlet at the north, by 

 Masonboro Inlet at the south, and from the 

 mainland by a sound about IVa miles wide, 

 consisting of open channels, salt marsh, a small 

 island (Harbor Island), and the Atlantic Intra- 

 coastal Waterway. 



Here a dune with a top width of 25 feet and a 

 top elevation of 12 feet above mean low water was 

 constructed. The inshore toe of the dune is at or 

 near the building line. Figure 3 shows the beach 

 before and after restoration. 



One of the first requirements for coastal plan- 

 ning is adequate technical knowledge of shore 

 processes, storm frequencies, and storm-tide eleva- 

 tions for the area concerned. On our Pacific Coast, 

 including Alaska and Hawaii, the effects of tsu- 

 namis (earthquake-generated waves) also must be 

 considered. This information, appUed to the topo- 

 graphy of the coastal area and the adjoining 



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