The Determination of Minimum Flows for Sulphur Springs, Tampa

DRAFT
one the indicators were the frequency and duration of salinity incursions in the upper spring
run. For goal number two the indicators were the volumes of water in the lower river less
than 4 ppt and less than 11 ppt salinity. For goal number three the indicator was
maintaining temperature changes within a thermal refuge region in the river to less than two
degrees Celsius.
These indicators were used to evaluate the potential for significant harm to the ecology of
the spring run and the lower river that could result from reductions in springflow due to
withdrawals. The responses of the spring run and river to various rates of flow were
evaluated. The final determination of what constitutes significant harm and minimum flows
for Sulphur Springs rests with the Governing Board of the District. That determination will
be largely based on the approach and technical information presented in this report and the
resulting peer review.
1.4 Content of Remaining Chapters
The remainder of this report presents the results of the District's analyses of minimum flows
for Sulphur Springs. Chapter Two describes the physical and hydrologic characteristics of
the spring pool and the response of springflow to historic rates of water use. Chapter Three
describes the relationships of flows from the spring pool to the ecological characteristics of
the spring run and Lower Hillsborough River. Based on these relationships, Chapter Four
presents the District's approach for determining minimum flows for Sulphur Springs,
including the identification of management goals and ecological indicators on which the
minimum flows are based. Chapter Five presents the results of the District's minimum flow
analysis and the proposed minimum flows. The report concludes with the Literature Cited
and Appendices.
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