Alafia River Minimum Flows and Levels - Southwest Florida Water ...

973 to 3091 ft. Local (cross-section site) flows needed to overflow the river's
banks ranged from 566 to 2445 cfs (see Appendix RH for channel bank and
other floodplain feature elevations and associated flows). Mean flow at the Lithia
gage corresponding to the flow necessary for exceeding the elevation of the
lowest bank on either side of the river averaged 1160 cfs; flows at the gage that
would be sufficient for the river to overflow both banks averaged 2269 cfs (Table
5-1).
Elevation (feet)
40
35
30
25
20
15
10
5
0
-1600 -1400 -1200 -1000 -800 -600 -400 -200 0 200 400
Cumulative Length (feet)
Figure 5-4. Elevation profile for floodplain vegetation cross-section (transect) 49.
Distances (cumulative length) are shown centered on the middle of the river channel.
Six vegetation classes were identified at the floodplain vegetation cross-section
sites and their mean elevations at each transect are indicated in Figure 5-5.
Detailed descriptions of the vegetation classes, which include Cypress/Palm
Swamp, Cypress Swamp, Hardwood Swamp, Wet Hardwood Hammock, Dry
Palm Bank and Dry Hardwood Hammock, are provided in PBS&J (2004). Mean
elevations of vegetation classes were not related to location along the river
channel and there were no apparent differences between "upstream" or
"downstream" vegetation classes in the study. Consequently, elevation data were
normalized to channel elevations at each transect for further comparisons.
Normalized mean elevations for Cypress Palm Swamps, Cypress Swamps and
Hardwood Swamps did not differ, but the swamp classes were found at lower
elevations than the Wet Hardwood Hammocks (Wilcoxon Signed Rank, S=-13,
p