opened up the potential problem of 

 salt water intrusion along the 

 southeast coast. The drought of 

 1943 through 1945 amplified the 

 potential for this problem and 

 started the search for a long term 

 solution. 



In 1949 the Florida Legislature 

 authorized the formation of the Cen- 

 tral and Southern Florida Flood 

 Control District (CSFFCD). The 



purpose of this agency was to de- 

 velop a comprehensive, coordinated 

 means by which to regulate both 

 flood waters and salt water intru- 

 sion. 



By 1953 the CSFFCD had con- 

 structed a system of levees along 

 the eastern boundary of the Ever- 

 glades to retain freshwater runoff 

 during the dry season. By 1960 the 

 levees had been expanded to enclose 

 what are now referred to as Conser- 

 vation Areas 1 and 2 in the northern 

 Everglades. By 1962 a levee running 

 parallel to the Tamiami Canal was 

 completed, giving partial enclosure 

 to Conservation Area 3. By 1967 all 

 but a 11.4 km (7.1 mi) gap along the 

 latter's western boundary was com- 

 pleted, thus allowing regulation of 

 flow to the present study area. 



In 1967 canal C-111 was con- 

 structed along the southeastern 

 boundary of the study area as part 

 of CSFFCD's South Dade County Area 

 Plan of Improvement (Barnes et al. 

 1968). The canal, an extension of 

 canal-levee L-31W along the Atlantic 

 Coastal Ridge, was intended to pro- 

 vide flood control, drainage, and 

 navigation benefits for the area 

 from Florida Bay on the south to 

 Tamiami Trail on the north. This 

 area is now known as the East Ever- 

 glades. A salinity barrier (S-197 

 of CSFFCD) was constructed and be- 

 came operational near the confluence 

 of the canal with U.S. Highway 1 in 

 1968 (Meyer and Hull 1969). 



Working from our initial con- 

 ceptual model of regional ecological 

 processes. Figure 31 presents a 

 modified version which emphasizes 

 and summarizes the major pathways of 

 the hydrologic cycle as it occurs 

 within the study area. Each of the 

 storages in Figure 31, or groups of 

 closely associated storages, is 

 discussed somewhat in sequence with 

 the natural flow of water, and the 

 chemical energy contained within it. 

 Some of these pathways have been 

 discussed in the section on climatic 

 factors. In this section we focus 

 primarily on patterns in the ground 

 related pathways of the hydrologic 

 cycle, such as spatial and temporal 

 variations in flow through and 

 storage of water, and fresh and 

 saltwater fluctuations. 



5.2 CONSERVATION AREA 3 



Conservation Area 3 is divided 

 into two areas, 3A and 3B, having 

 surface areas of 2,037.2 and 331.2 

 km 2 (786.6 and 127.9 mi 2 ) re- 

 spectively (Figure 32). Regulation 

 of the area varies from 2.9 to 3.2 m 

 (9.5 to 10.5 ft) providing a maximum 

 total storage capacity of 380,000 

 acre-feet. Due to the sloping topo- 

 graphy (4 m or 13 ft on the north to 

 2.1 m or 7 ft on the south), most of 

 the storage is at the lower end. 

 High evapotranspiration losses due 

 to dense vegetation cover tend to 

 restrict the area's utility as a 

 storage reservoir. In addition to 

 receiving input from upstream pump- 

 age (Canal 123) and direct rainfall, 

 Conservation Area 3A also receives 

 some runoff from the Big Cypress 

 Basin via the L-28 tieback canal 

 (SFWMD 1977). 



Prior to the construction of 

 the levees on the south of Conserva- 

 tion Area 3, flow out of the area 

 occurred via numerous bridges be- 

 neath Tamiami Trail. In general, 

 the flow was then intercepted and 



72 



