The Determination of Minimum Flows for Sulphur Springs, Tampa

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DRAFT
at which further withdrawals would be significantly harmful to the water resources or
ecology of the area.” Minimum levels are defined as “the minimum water levels shall be the
level of groundwater in an aquifer and the level of surface water at which further
withdrawals would be significantly harmful to the water resources of the area.” It is
generally interpreted that ecological resources are included in the "water resources of the
area mentioned" in the definition of minimum water level. The establishment of MFLs for
flowing watercourses can incorporate both minimum flows and minimum levels. However,
as described in Chapter 4, the establishment of MFLs for Sulphur Springs involved only a
flow component, and the term minimum flows is used in this report with specific reference
to Sulphur Springs.
Section 373.042 F.S. further states that MFLs shall be calculated “using the best
information available. When appropriate, minimum flows and levels may be calculated to
reflect seasonal variations. The Department [of Environmental Protection] and the
governing board [of the relevant water management district] shall also consider, and at their
discretion may also provide for, the protection of non-consumptive uses in the
establishment of minimum flows and levels.”
Guidance regarding non-consumptive uses of the water resource to be considered in the
establishment of MFLs is provided in the State Water Resources Implementation Rule
(Chapter 62-40.473, Florida Administrative Code), which states that “consideration shall be
given to the protection of water resources, natural seasonal fluctuations in water flows or
levels, and environmental values associated with coastal, estuarine, aquatic and wetlands
ecology, including:
(1) Recreation in and on the water;
(2) Fish and wildlife habitats and the passage of fish;
(3) Estuarine resources;
(4) Transfer of detrital material;
(5) Maintenance of freshwater storage and supply;
(6) Aesthetic and scenic attributes;
(7) Filtration and absorption of nutrients and other pollutants;
(8) Sediment loads;
(9) Water quality; and
(10) Navigation.”
Identification of severe water resource problems in the Northern Tampa Bay area in the
mid-1990s (e.g., see SWFWMD 1996) precipitated renewed interest by the Florida
Legislature concerning the establishment of MFLs. In 1997, Section 373.042 F.S. was
revised to provide additional guidance on factors to be considered when establishing MFLs.
According to Section 373.0421(1a), F.S., when establishing MFLs the governing board
“shall consider changes and structural alterations have had, and the constraints such
changes or alterations have placed, on the hydrology of the affected watershed, surface