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

decrease in both phosphorus and fluoride concentrations in the late 1970s.
Although low flows decreased considerably since the 1960s and 1970s, they
have not decreased below the levels seen in the earlier part of the record
(1940s). Since rainfall was generally higher in this earlier period, one would
expect flows during this earlier period to exceed or at least match those of the
1960s-1970s, but this is not the case. While Stoker et al. (1995) attributed the
flow decline to a lowering of the potentiometric surface, Hickey (1998) was
correct in attributing this decline to climate and curtailment of mining related
discharges. This is also confirmed by decreases in parameter concentrations
that are associated with groundwater inputs (e.g., calcium and sulfate).
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