Alternative water supplies in treated river water and desalinated seawater allowed Tampa Bay Water to reduce groundwater withdrawals, a requirement of the original Consolidated Permit.
When the permit was renewed the first time in 2011, an additional requirement called for Tampa Bay Water to complete a Permit Recovery Assessment Plan evaluating the environmental recovery and identifying any remaining adverse impacts from groundwater pumping before the permit was to be renewed again in 2020.
To address this requirement, Tampa Bay Water developed a multi-year study of environmental health and the effects of its wellfield pumping reductions. Tampa Bay Water and the District agreed the plan would focus on the recovery of the wetland and lake water levels as the environmental features of greatest concern.
The Consolidated Permit is Tampa Bay Water’s most significant and important permit — it accounts for about half the water we deliver, making it the single-largest piece of the water supply portfolio for the Tampa Bay region.
Using methodologies developed in cooperation with the District, Tampa Bay Water assessed the environmental recovery at lakes and wetlands achieved through the reduction of groundwater pumping in the northern wellfields. Throughout the assessment, Tampa Bay Water and the District documented site conditions, evaluated data and verified recovery results at many lakes and wetlands. Between 2012 and 2020, utility and district staff completed more than 130 technical meetings and field reviews. In total, they studied 1,360 lakes and wetlands through this evaluation, and this recovery assessment plan is the first of its kind to be performed in the United States.
May 2006: near-total treefall and extensive soil subsidence. May 2016: an increase of seven feet of water at the end of the dry season.
May 1997: dry wetland with upland vegetation. May 2016: wetland is full, with a return of wetland plants and cypress trees.
CYPRESS CREEK WELLFIELD
September 1999: low or absent water levels, treefall and upland vegetation. September 2010: wetlands vegetation re-established after water levels return.
STANFORD LAKE (BETWEEN CYPRESS CREEK AND CROSS BAR RANCH WELLFIELDS)
2002: lake is dry. September 2012: lake is once again full.
LAKE RALEIGH, COSME-ODESSA WELLFIELD
May 2002: tremendous lake recession. 2016: water levels reach elevations not seen since Hurricane Donna in 1960. (Water level is 16.5 feet higher.)
STARVATION LAKE (NORTHWEST HILLSBOROUGH COUNTY)
2001: boat ramp leads to more dirt. August 2015: lake is flush with water. (Water level is 14 feet higher.)
Tampa Bay Water has pumped less than the 90 mgd annual average permit limit since 2010. In fact, the annual average pumping rate for the wellfields averaged 80.7 mgd for the past 10 years. Thanks to this reduced pumping, coupled with normal to slightly above average rainfall, area lakes, wetlands and other surface water bodies across the northern Tampa Bay area have recovered.
Most aquifer levels across the northern Tampa Bay area are at their highest in more than 40 years.
The Recovery Assessment Plan demonstrates that 85% of the monitored lakes and wetlands have fully recovered or were never impacted by wellfield pumping. Wetlands and lakes on and near all wellfields have recovered to their fullest extent given the development and drainage changes that have occurred on surrounding lands. The few wetlands and lakes that did not fully recover, all showed significant improvement, and only one wetland showed signs of continued adverse impact due to wellfield pumping and requires mitigation.
The science clearly shows the environment has recovered through the sustainable operation of our area wellfields.
Recovery is a long and steady process. Tampa Bay Water continues to carefully monitor the environment in and around regional wellfields and manages and shifts groundwater production in response to climatic and environmental factors.
Land that was developed during times of higher pumping or extended dry periods must maintain a lower water table to avoid flooding of homes and neighborhoods.