The Determination of Minimum Flows for Sulphur Springs, Tampa

Fig. 2-21 Temporal trend of specific conductance and salinity in the Sulphur
Springs Pool. Kendall-Theil slope shown ........................................ 2-23
Fig. 2-22A Specific conductance in the Sulphur Springs cave system on
November 15, 1998. Adapted from Schrueder, Inc. Used with
permission of the City of Tampa...................................................... 2-24
Fig. 2-22B Know Extent of Sulphur Springs Cave System Accessible to
Divers .............................................................................................. 2-25
Fig. 2-23 Average daily values of water levels and specific conductance for
Sulphur Springs Pool for 1999 through 2002................................... 2-26
Fig. 2-24 Water level and specific conductance response to withdrawals from the
Sulphur Springs Pool for two periods during 2001 .......................... 2-28
Fig. 2-25 Average specific conductance values for each day of the year for 2001
and 2002 with a LOESS line fitted to the 2001 data ........................ 2-29
Fig. 2-26 Residual values for conductance vs. day of the year and pumpage
from Sulphur Springs for 2001......................................................... 2-29
Fig. 2-27 Response of water levels and conductance to withdrawals after
modification of water diversion facilities at Sulphur Springs,
March - September, 2002................................................................ 2-31
Fig. 2-28 Temporal trend in nitrate nitrogen in the Sulphur Springs Pool for 1991-
2003 (three values not shown) ........................................................ 2-35
Chapter 3 – Ecological Resources of Sulphur Springs and the Lower
Hillsborough River
DRAFT
Fig. 3-1 Stage duration curves of water levels in the upper spring run and the
Hillsborough River near the mouth of the spring ............................... 3-2
Fig. 3-2 Time series graph of water levels in upper spring run and river near the
mouth of the spring during a period of normal flow from the spring pool
(January 14 - 21, 2001) ..................................................................... 3-3
Fig.3-3 Stage duration curves for water levels in the upper spring run for
periods of normal flow (> 20 cfs) and low flwo (< 5 cfs)..................... 3-4
Fig. 3-4 Time series graph of water levels in upper spring run and river near the
mouth of the spring during a period of low flow (3.5 cfs) from spring
pool (May 1 - May 6, 2001)................................................................ 3-4
Fig. 3-5 Average daily salinity values for the spring pool and the data recorder
in the upper spring run over pumpage from the pool for 1999 - 2002 3-6
Fig. 3-6 Average daily salinity values for the spring pool and the data recorder
at the spring mouth over pumpage from the pool for 1999 - 2002..... 3-7
Fig. 3-7 Average water column pH values for stations in the spring run sampled
by the SWFWMD between November 21, 2001 and June 20, 20023-10
Fig. 3-8 Average yearly flows to the lower river from the Hillsborough River
Reservoir ......................................................................................... 3-27
Fig. 3-9 Number of no-flow days per year from the Hillsborough River Reservoir3-28
Fig. 3-10 Flow Duration curve for daily flow values from the Hillsborough River
Reservoir ......................................................................................... 3-29
Fig. 3-11 Time series of percent of daily gaged ............................................. 3-30
Fig. 3-12 Periods of record for salinity, temperature, and dissolved oxygen
measurements at fixed location water quality sites sampled by the
vi