As population in southern Hillsborough County grows, demand for drinking water is growing along with it. Since March 2022, average demand has increased by more than 5% — nearly 3 million gallons of water per day (mgd), and it continues to increase. The South Hillsborough Wellfield Phase One project could send an additional annual average of 2.3 mgd to Hillsborough County.
Tampa Bay Water and Hillsborough County have agreed to turn an existing test well into a new drinking water well to help meet water needs. This well is a smaller version of one of the projects Tampa Bay Water studied extensively for the Master Water Plan. Pending permit approval by the Southwest Florida Water Management District (District), the well could bring an additional annual average of 2.3 mgd to southern Hillsborough County by late 2025.
The test well and three monitoring wells were constructed in the Balm area in 2021 during feasibility studies for a larger South Hillsborough Wellfield via Aquifer Recharge Credits (SHARP) project. During the study, Tampa Bay Water conducted an aquifer performance test which showed that the wellfield was technically feasible, environmentally sound and economical. The wellfield concept was not selected for implementation at that time, but Hillsborough County and Tampa Bay Water are pursuing one well to boost supply, at least, until the South Hillsborough Pipeline brings more water to the area in 2028.
Tampa Bay Water conducted a second aquifer performance test in June 2023 to collect additional aquifer and water quality data.
Southern Hillsborough County is designated a Water Use Caution Area by the District. To address growing water needs in this area, the District has adopted the “net benefit” concept where any new withdrawal from the aquifer must be offset by another source and result in an additional positive effect within the same aquifer.
Since 2015, the County has been recharging the salty aquifer along the coast to prevent saltwater intrusion, which provides a benefit to the aquifer. This allows Tampa Bay Water to withdraw fresh water several miles away without harming the aquifer.
No recharge water will be withdrawn by the new well, which is located 5 miles inland.
Tampa Bay Water will:
Hillsborough County will:
The well is more than 900 feet deep; in this area the deep aquifer is separated from the shallow aquifer by a 250-feet thick clay confining layer. That means water level changes in the deep Upper Floridan Aquifer do not affect surface water features; lakes, wetlands, springs and rivers in the area will not be affected by the new well.
Additionally, Tampa Bay Water engineers conducted modeling, which showed minor drawdown effects from pumping — about 3 feet in the Upper Floridan Aquifer at the well, 2 feet at a distance of 300 feet from the well and 1 foot or less at legal existing users, which includes residential wells. Given that water levels in this area normally fluctuate 15-20 feet, this minimal withdrawal is not expected to impact other existing legal groundwater users.
Tampa Bay Water has a Good Neighbor Policy and will investigate any water-level related well complaints. If the investigation shows that pumping at Tampa Bay Water’s well caused a problem with a particular well, Tampa Bay Water will restore that well at no cost to the owner.
Water from the well will go directly to Hillsborough County, instead of the regional system. Not only will it help meet the County’s needs, but it will also free up 2.3 million gallons of water per day from the regional system. The well will be used at least until the new South Hillsborough Pipeline is operational in 2028 and beyond if both parties agree to an extension.
Tampa Bay Water’s cost for the South Hillsborough Wellfield Phase One design and construction is approximately $1.8 million.
Public input plays an important role in all Tampa Bay Water projects. Input on the larger, South Hillsborough Wellfield via Aquifer Recharge Credits project was provided via online surveys and public meetings. Results of that outreach are linked below
Public information and outreach on South Hillsborough Wellfield Phase One is ongoing.
For more information please email projectinfo@tampabaywater.org or call (813) 486-0361.
SOURCE: Floridan Aquifer
PROJECT YIELD: 2.3 million gallons per day
KEY POINTS: new groundwater; net benefit to aquifer; within high growth area
