■ 

 2 





5 

 < 



5 

 X 



a 



3 

 O 

 cc 

 I 



O 

 z 



D 

 CC 



170 



150- 



130- 



110 



90 



70 



50 



2. 30 



9- 10- 



30 



TAMIAHl TRAIL 

 ( Mi ami to 40-mile Bend ) 

 Avenges of three months of 

 flow data in acre feet. 



N 



M 



1955 1956 



WHITEWATER BAT t 

 . Bottom salinity in opt (Averages 

 \of three months, set back three. 

 Vmonths to account for lag 



\/ 



\i 



Sal 1 n i ty graph irverted 

 so Chat low values show 

 as peaks. 



Figure 34. Relationships between 

 salinity in Whitewater 

 Bay and freshwater 

 runoff across Tamiami 

 Trail (adapted from 

 Tabb et al. 1962). 



~~>S M1RCH 962 



Figure 35. Representative iso- 

 halines in Whitewater 

 Bay during wet and dry 

 seasons (adapted from 

 Tabb et al. 1962). 



seepage discharge from the Tamiami 

 Canal between levees 30 and 67A 

 generally peaks in August through 

 October and bottoms out in March or 



April. As mentioned in the discus- 

 sion of Conservation Area 3A, a 

 marked decrease in flow across this 

 section of Tamiami Trail occurred 

 after 1960 as the result of increas- 

 ed water retention behind levee 29 

 and diversion of flow to the west by 

 levee 67A. 



Schneider and Waller (1980) 

 claim that surface water levels in 

 the Taylor Slough headwaters display 

 a relatively smaller range of fluc- 

 tuation than in areas to the north 

 (Shark River Slough) and south 

 (canal C— 1 11). Apparently, surface 

 water levels in the Taylor Slough 

 headwaters are less strongly impact- 

 ed by drainage controls than are the 

 other two areas. 



However, groundwater records in 

 the same area suggest that changes 

 have occurred in the below ground 

 water levels subsequent to the canal 

 and levee construction of the 

 1960's. Specifically, groundwater 



tables exhibit less seasonal vari- 

 ability, with some indication that 

 seasonal lows are now lower than 

 prior to water level control. In 

 the wells close to canal C— 111 this 

 is particularly obvious. Control 



structure S-18C on C— 111 opens auto- 

 matically when upstream stage reach- 

 es 0.6 meters (2 ft), effectively 

 dampening the peak of "average" high 

 water levels. 



Surface flow from upper Taylor 

 Slough is measured as it passes 

 under a 12.1 km (7.5 mi) stretch of 

 Context Road through no less than 80 

 culverts. Downstream, near Home- 

 stead, flow is again measured 

 beneath a 4.8 km (3 mi) stretch of 

 State Road 27. Schneider and Waller 

 (1980) present flow duration curves 

 for these two stations that show the 

 upper slough effectively drying up 

 for much of the average year. Dif- 

 ferences in flow durations during 



82 



