The Determination of Minimum Flows for Sulphur Springs, Tampa

DRAFT
apparently declined over time. Studies performed by the City of Tampa in 1958
confirmed a connection between Sulphur Springs and Curiosity Sink and also Blue Sink,
which are located approximately 2.5 miles (4 km) northwest of Sulphur Springs. Tracer
dyes indicated flow rates in the range of 4,200 to 9,200 ft per day (1,280 to 2,800
meters per day). Stewart and Mills (1984) visited the Blue Sink complex in 1963-64 and
noted that the sinks were approximately 20 to 30 feet (6.1 to 9.1 m) deep with water
visibly flowing at the bottom. However, by 1981 the sinks were only about 6 feet (1.8 m)
deep and dry. The connection between Sulphur Springs and the Blue Sink complex had
been lost due to the build up of trash and sediment, which effectively plugged the sinks.
A dye test was conducted by the City of Tampa in 1987 to determine if the connection
still remained between Blue Sink and Sulphur Springs. The dye never arrived at the
spring indicating that the connection was sealed.
Figure 2-17. Known sinkholes locations near Tampa, Florida.
In 1989, Environmental Engineering Consultants, Inc. conducted additional dye tracer
tests to verify the hydraulic connection between Alaska and Poinsettia (also called
Jasmine or Trinity) sinks to Sulphur Springs. Alaska sink is approximately 549 m (1,800
ft) northwest of Sulphur Springs and Jasmine is 7,500 feet (2,286 m) north of Sulphur
Springs. The calculated flow rate for the flow between Alaska sink and Sulphur Springs
was 12,900 ft per day (3,932 meters per day). The results for the Poinsettia sink
indicated a flow rate of approximately 8,200 ft per day (2,499 meters per day). The test
derived flow rates are, of course, head dependent. The greater the hydraulic gradient
the more pronounced the flow. Consequently, if levels are reduced at Sulphur Springs
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