Master plan developed to meet water demand

Providing adequate drinking water to Florida’s Tampa Bay residents is becoming more difficult as development outpaces supply. “Our current water supply system is straining to keep up,” says Michelle Klase, spokesperson for Florida’s West Coast Regional Water Supply Authority.

To meet the area’s drinking water needs, the authority has developed a 20-year master plan comprising nine projects in three counties: Hillsborough, Pinellas and Pasco. It will involve wetlands restoration as well as the creation of an interconnected, regional system between new and existing water supply facilities.

Cone Ranch, a 12,700-acre tract in northeastern Hillsborough County, is the first site to be developed under the plan. The authority purchased the land in 1988 after preliminary testing identified it as a reliable source of abundant, high-quality water with an estimated capacity of approximately 12 million gallons per day.

Surface water and groundwater levels, as well as rainfall and streamflow, have been monitored at Cone Ranch for 10 years. A phosphate processing plant located adjacent to the site prompted hydrologic testing, which was completed last month by Leggette, Brashears & Graham, a Tampa-based groundwater consulting firm.

Since 1988, a wastewater recycling system has been installed at the processing plant. The latest testing revealed that the system is an adequate buffer between the plant and the Cone Ranch wells. For additional protection, the authority used the data it compiled and produced computer models to select well locations and pumping rates that would prevent the migration of contaminants into the water supply.

In addition to drilling Cone Ranch for its water supply, the authority plans to remediate wetlands at the site. Years ago, the ranch was used for cattle raising, sod farming and other agricultural activities that required substantial drainage of the land. As a result, the owners channeled streams and installed a ditch system to speed the removal of rainwater.

“Dechanneling” Cone Ranch is part of the authority’s plan for the site. A pilot program to block ditches and channels and observe the effects on the water table is under way. If successful, the process will improve recharge to the aquifer and improve water quality within the Hillsborough River tributary. It will partially restore natural drainage patterns to the site, Klase says.

The authority is funding the drilling and testing at Cone Ranch. The initial budget covers testing, design, well construction supervision, aquifer performance testing and public involvement. Drilling began last October and, along with the hydrologic testing, was completed last month. The region’s water regulator, the Southwest Florida Water Management District, also installed monitoring wells across the ranch. Each pair of wells consisted of an aquifer well and a surficial aquifer well to collect water level data and assist the overall testing program.

With testing complete, the authority is proceeding with phases II and III, which will encompass water use permitting and well-field design and development. When the Cone Ranch wells are connected to the authority’s regional system (the project is scheduled for completion by 2001), two pipeline connections will allow production to be shifted among sources as needed.

“By developing diverse water sources including surface water, repurified water and groundwater, we will have sufficient reserve capacity to shift production in response to climatic and environmental conditions,” Klase explains. “In times of heavy rain, for example, we can rest the wellfields and rely more on surface water. If one wellhead area is environmentally stressed, we can rotate to a well in another location.”