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mason. SHORE-CONTROL PROBLEMS, 



[Ch. 15 



harbor, shoaling it to such an extent that it became partially unusable. 

 Concurrently, erosion of the downdrift shore occurred, finally extend- 

 ing its effects almost 10 miles downcoast from Santa Barbara. 



The evidence at hand indicates that the net results of the action of 

 shore processes over the period of record is an average annual loss of 



Fig. 4. Fire Island Inlet, New York, before construction of jetty, September 

 1939. (Photo by Beach Erosion Board.) 



land in the United States equivalent to about a 1-foot strip over our 

 entire 52,000 miles of shore line, a loss in land area approximating 

 6,400 acres per year. In some areas loss is general and excessive, 

 for example, the Chesapeake Bay area, where entire islands have dis- 

 appeared by erosion within the memory of man, and where the un- 

 protected shores of both developed and agricultural lands are now 

 being lost at rates as high as 15 feet or more per year. In other limited 

 sections land is being gained, as at Fire Island Inlet on the south shore 

 of Long Island (Figs. 4 and 5), where littoral drift is being trapped by 

 a recently constructed jetty. 



