The Determination of Minimum Flows for Sulphur Springs, Tampa

DRAFT
withdrawal rate of 31 cfs during April 26 to May 11 and two days in late May. The effects
of these higher pumping rates on lowering water levels are apparent. For most of this
experimental period, however, withdrawals were considerably smaller. Withdrawal rates
near 10 cfs were maintained for a total of 38 days between mid-April and mid-June. The
effect of the 10 cfs diversion rate on water levels in the pool were considerably less than
withdrawals near the historic rate. In addition, a two-week period of pumping at a rate of
17 cfs began on June 20 th . Pumping at this rate lowered water levels in the pool to
about 6.7 to 6.9 feet. A brief change to a pumping rate of 11 cfs on June 30 th resulted in
a quick rebound in water levels.
8
Gage Height (ft)
Daily Pumpage (cfs)
6
4
2
30
20
10
0
Conductivity
Pumpage
Gage Height
SSPmp_drwdwn3.grf
5000
4000
3000
2000
1000
0
Conductivity (umho/cm)
4/4/02 5/24/02 7/13/02 9/1/02
Figure 2-27. Response of water levels and conductance to
withdrawals after modification of water diversion facilities at Sulphur
Springs, March - September, 2002.
Specific conductance values did not show a clear response to any of the withdrawal
rates implemented during the experimental period. Similar to the seasonal trend shown
in Figure 2-20, conductance values declined during April to reach minimum values in
May and then rebounded in June. Changes in withdrawals rates showed very little effect
on this seasonal pattern. This lack of response may have been related to the brief
duration of the high pumping events, or that much of the pumping was done at lesser
withdrawal rates.
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