BEACH EROSION STUDIES 



Beach erosion control studies of specific localities are usually made 

 by the Corps of Engineers in cooperation with appropriate agencies of 

 the various States by authority of Section 2 of the River and Harbor Act 

 approved 3 July 1930. By executive ruling the costs of these studies are 

 divided equally between the United itates and the cooperating agencies. 

 Information concerning the initiation of a cooperative study may be ob- 

 tained from any District or Division Engineer of the Corps of Engineers, 

 After a report on a cooperative study has been transmitted to Congress, 

 a summary thereof is included in the next issue of this Bulletin. 

 Summaries of reports transmitted to Congress since the last issue of the 

 Bulletin and lists of completed and authorized cooperative studies follow, 



SUT€:l&RIES OF REPORTS TRA'CMTTED TO CONGRESS 



PINELLAS COUNTY, FLORIDA 



Pinellas Coiinty is located on the Gulf Coast of Florida, about 

 midway of the peninsula. Its shore line consists of momerous keys or 

 barrier islands, separated from the mainland by generally shallow tidal 

 lagoons, and from each other by shallow natural passes. The study area, 

 about 25 miles of shore line, comprises the four most developed of these 

 keys, namely Clearwater Beach Island, Sand Key, Treasure Island, and 

 Long Key, These four islands contain 13 separate incorporated communities. 

 Six causeways and bridges connect these islands with the mainland. The 

 principal activities in this area are tourish accommodation, citrus fruit 

 growing and comr'ercial fishing. 



The four islands have a permanent population of about 11,000, but 

 the summer and winter tourist trade increases the population to more than 

 26,000 the year round. The permanent population of the general tributary 

 area, comprising Pinellas and Hillsborough Counties which include the 

 cities of Clearwater, St. Petersburg and Tampa, is in excess of U00,000, 

 Daring the winter season this figure is about doubled by the influx of 

 winter residents and tourists. Of the Gulf frontage for which protection 

 is required, about one-eighth is publicly owned, including one Federally 

 owned parcel 500 feet long. 



Geologically, the shore line under study is one of emergence^, with 

 the nvunerous barrier islands and beaches having been formed in geologically 

 recent times by the action of waves and currents. The low narrow keys are 

 composed of recent marine deposits consisting of quartz, sand and shell in 

 varying mixtures. Beach samples taken at about mean tide level had median 

 diameters of from 0.2 to 0,3 millimeter after removal of shell, and a 

 variable shell content ranging up to about 30 percent. 



Tides in the vicinity of the study area are the mixed type, with 

 mean and spring ranges averaging about 1.5 feet and 2,0 feet respectively. 

 The maximum storm tide stage may have reached about 13 feet above mean low 

 water, but storm tide stages exceeding 5 feet above mean low water are rare. 



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