What happened to the old swimming hole? - In 1920s Sulphur Springs was a booming Mediterranean style resort. The neighborhood had it's own hotel, movie theater, restaurant, hardware store, bank and street cars brought visitors from Tampa to visit the spring fed swimming hole and scenic area surrounding Hillsborough River.

Fifty years later bulldozers showed up and despite protests of local citizens, demolished the old hotel to make space for a dog track parking lot.

Today only the renovated movie theater, the white ornate gazebo and some dusty old postcards remind us of the old days.

"Modern" Sulphur Springs appear to suffer the same fate many close to downtown neighborhoods are: boarded up storefronts, congested traffic and in great need of TLC.

What happened to the swimming hole?

City of Tampa built and maintains a beautiful swimming pool complete with slide, picnic areas, changing rooms and lifeguards; all that right next to the old spring.

The round pool surrounding the original spring itself has been fenced off, it's overflow being directed to Hillsborough River and when the need arises some water is pumped out to support the city water supplies.

The spring discharges from a low horizontal crack in limestone at 30 feet and the flow's strength changes according to local rains. But for cave explorers trying to squeeze thru this restriction, the flow is always strong enough to require use of a pull rope and some very clever gear and gas management techniques.

The original explorers in early 1990s considered use of scooters in this cave questionable due to poor visibility and limited space but they were able to explore and survey over 3000 feet of passage.

The exploration was renewed in early 2002 at the request of the City of Tampa and Coastal Karst Foundation team led by Michael Garman continues exploring beyond where the main passage splits into the Orchid Tunnel and the Alaska Tunnel. The divers equipped with water quality detection instruments discovered a vent discharging salt water into the Alaska Tunnel.
Radiolocation and GIS were used to reference the exact location of the tunnels to the surface features and we are hoping to get answers to where is the salt water coming from as well as what are the sources of pollution.

:: The Research

::The Research

Sulphur Spring in Tampa, Florida is a freshwater spring that was developed into a circular pool surrounded by a concrete wall.
The pool's bottom is at about 30 feet of rushing water with the vent itself being a 5 feet wide and 2-3 feet high crack in the limestone. The cave profile changes frequently and steeply between shallow points at 30 feet and deep passages at 115 feet.
The 10-15 feet visibility in the tunnel can be called "chunky" - there is a constant shower of rusty colored material raining from the ceiling as well as nondescriptive "stuff" floating with the current.

While scootering over 3000 feet into the cave against treacherous flow that can bring even the most powerful scooters to a standstill, divers discovered several saltwater vents in the bottom of the tunnel. Using the Hydrolab® instrument mounted on a scooter, we were able to get data about salinity, dissolved oxygen, temperature and pH. The vents are easy to spot - they are surrounded by colorful but mostly snow-white growth of bacteria. In some cases the bacteria form soft fringes that undulate in the flow. Change of water density - the halocline - is a telling sign of the saltwater intrusion from these vents. Radio tracking methods are being used to pinpoint the exact location of the saltwater vents. Ultimately, we are hoping to determine the source of the saltwater intrusions.
Sulphur Spring is a property of the City of Tampa and is not opened to public access.