In USGS’s web page on Groundwater depletion:
The chart below shows monthly-mean water levels from 1964 to 2003 for a well in Cook County, sourthwest Georgia. The well is used for irrigation and public- supply purposes and offers a good visual representation of long-term groundwat er declines due to excessive pumping. [d]—data for the chart is available.
West-central Florida— Groundwater development in the Tampa-St. Petersburg area has led to saltwater intrusion and subsidence in the form of sinkhole development and concern about surface-water depletion from lakes in the area. In order to reduce its dependence on groundwater, Tampa has constructed a desalination plant to treat seawater for municipal supply.
That page lists some possible effects of groundwater depletionk including lowering of the water table, increased costs for the user, reduction of water in streams and lakes, land subsidence, and deterioration of water quality.
We already have some of these problems. Do we want to risk making them worse, possibly much worse, by letting a company from Houston, Texas dig under our Withlacoochee River and withdraw massive amounts of water for pipeline pressure testing?
PS: Gretchen Quarterman found this USGS document as well as the one used in USGS warns Withlacoochee River already leaks into Floridan Aquifer.