Trends and fluctuations of water levels in wells tapping the Floridan aquifer in west-central Florida during 1961-80 are described in this report. Water levels in most of the study area have not changed appreciably, except in parts of Hardee, Hillsborough, Manatee, Polk, and Sarasota Counties. In these areas, ground-water pumpage by industry and agriculture caused long-term declines of water levels. The largest declines are centered in the agricultural area of southern Hillsborough and northern Manatee Counties where pumpage lowered water levels more than 30 feet since 1964. Hydrographs of 10 wells show that, during 1976-80, the downward water-level trend discontinued in areas of heavy pumpage and, in areas not affected by pumping, water levels remained fairly unchanged. Water levels rose more than 20 feet from May 1975 to May 1980 in southwest Polk, Hardee , northeast Sarasota, northeast Manatee, and southwest Hillsborough Counties. In the heavily pumped area of northern Hillsborough County, water levels rose 5 to 10 feet. From September 1975 to September 1980, water levels in southwest Polk County rose more than 10 feet. (USGS)
