PALM BEACH COUNTY FROM lAKE WORTH INLET TO SOUTH LAKE WCRTH INLET, FLORIDA 



The study area comprises the 15.6-mile reach of shore on the east 

 coast of Florida betweeft Lake Worth Inlet and South Lake Worth Inlet. 

 The town of Palm Beach occupies the northern 10.5 miles of the sandy 

 barrier beach island about 70 miles north of Miami. The remainder of 

 the island is in the towns of Lake Worth, Lantana, and Manalapan. The 

 island, especially that portion in Palm Beach, is extensively developed 

 as a high-class winter resort. The permanent and winter populations of 

 the island are respectively about 5,000 and 25,000. About 1.3 miles of 

 the ocean shore is publicly owned, most of which is used for public 

 bathing beaches. The shore of the study area is exposed to waves of the 

 Atlantic Ocean. To the northeast the fetch is unlimited, but to the 

 east and southeast the incidence of swells is influenced by the shelter 

 afforded by the islands of the Bahama group. The predominance of energy 

 components is such as to produce a dominant southward littoral trans- 

 port. However, reversals in direction of transport occur, principally 

 in the summer. The mean and spring tidal ranges are respectively 2.8 

 and 3.3 feet. The two highest tides of record, 11.2 and 8.7 feet above 

 mean low water, occurred during hurricanes in 1928 and 1936 respectively. 

 A tide of 7 feet is considered suitable for design purposes, as a tide 

 of this height can be expected during hurricanes of medium intensity. 



Lake Worth Inlet was opened by dredging and two protective jetties 

 were constructed between 1918 and 1925. Since completion of the 

 structures, littoral drift has been impounded nearly to the capacity of 

 the north jetty, and the deficiency in supply has resulted in erosion of 

 the shore south of the inlet, in spite of artificial placement of about 

 3,500,000 cubic yards of sand on the beaches from 1944 to 1953, and 

 construction of numerous bulkheads, walls, emd groins. The total cost 

 of protective measures since 1926 has been estimated as approaching 4 

 million dollars. 



The only apparent natural source of littoral material to supply 

 the problem area is the eroding beaches north of Lake Worth Inlet. The 

 accumulation of sand at that inlet indicates a littoral drift rate of 

 about 230,000 cubic yards annually. This rate compares with losses 

 from the island due to deficiency of supply from 1929 to 1955 of 200,000 

 cubic yards landward of the 18-foot depth contour. However, 250,000 

 cubic yards of material were lost annually between the 18 and 30-foot 

 contours during the same period. In order to obtain a reasonably uniform 

 supply of material to the problem area, at the time the study was made 

 the cooperating agency was proceeding with the construction of a sand- 

 transfer plant on the north jetty at Lake Worth Inlet. It is estimated 

 that the plant will transfer an average of about 100,000 cubic yards of 

 sand across the inlet annually. 



A Federal project, adopted May 17, 1950, authorized Federal parti- 

 cipation, subject to certain conditions, in the improvement and pro- 

 tection of the shore at Palm Beach by placing up to 1,000,000 cubic 

 yards of suitable material on the beach in five stockpiles. The 

 authorized Federal participation is one-third of the costs of this work 



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