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

medium (Block 2) and high (Block 3) flows are shown along with period of
record median daily flows for the Alafia River at Lithia. .............................2-38
Figure 2-17. Annual percent exceedance flows (points) for the Alafia River at
Lithia gage displayed with a 5-yr running average (line)............................2-42
Figure 2-18. Annual percent exceedance flows (points) for the North Prong of the
Alafia River gage displayed with a 5-yr running average (line). .................2-44
Figure 2-19. Annual percent exceedance flows (points) for the South Prong of the
Alafia River gage displayed with 5-yr running average (line). ....................2-46
Figure 2-20. Phosphorus and fluoride concentrations in the Alafia River and the
North and South Prongs. ...........................................................................2-48
Figure 2-21. Land use in the watershed upstream of USGS gage sites on the
South and North Prongs of the Alafia River based on mapping conducted in
1972, 1990 and 1999.................................................................................2-50
Figure 2-22. Graphical results of Kendall’s tau test for trend in mean annual flows
for the South Prong of the Alafia River for the period 1970 to 1999. Both the
OLS and Thiel best fit lines are shown. The slope of the Thiel line is -0.1918
with a p value of 0.8028.............................................................................2-51
Figure 2-23. Plots comparing decadal median daily flows normalized by
watershed area for the Alafia River at Lithia and the North and South Prongs.
...................................................................................................................2-54
Figure 2-24. Comparison of selected annual percent exceedance flows
normalized by watershed area for the Alafia River at Lithia and the North and
South Prongs.............................................................................................2-55
Figure 2-25. Lithia Springs Major bathing area being utilized for recreation. ...2-58
Figure 2-26. Photographs showing pumping platform located above Buckhorn
Springs Main (upper photo) and Buckhorn Creek downstream of the spring
vent (lower photo). .....................................................................................2-59
Figure 2-27. Daily flow record for Lithia Springs Major corrected for withdrawals.
...................................................................................................................2-61
Figure 2-28. Relationships between Lithia Springs Major discharge and stage.
Upper panel shows gage height (water surface elevation in feet above
NGVD) versus discharge for all available data. Lower panel shows gage
height versus discharge when flows in the Alafia River are 70 cubic feet per
second or less............................................................................................2-62
Figure 2-29. Graphical results of Kendall's tau for trend in daily flow (corrected for
withdrawals) for Lithia Springs Major for period 1983 to 2002. The slope of
the Thiel line is 0.00245 with a p-value of 0.0000. .....................................2-63
Figure 2-30. Daily flow records for Buckhorn Springs Main corrected for
withdrawals................................................................................................2-64
Figure 2-31. Graphical results of Kendall's tau for trend in daily flow (corrected for
withdrawals) for Buckhorn Springs Main for period 1987 to 2002. The slope
of the Thiel line is 0.00047 with a p-value of 0.0000. .................................2-64
Figure 2-32. Phosphorus concentrations in water samples collected by the USGS
at the Alafia River at Lithia gage. Upper plot is time series plot; middle plot is
concentration versus flow, and the bottom plot is time series plot of residuals
of phosphorus concentration regressed against flow.................................2-68
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