A September 1980 potentiometric-surface map of the Southwest Florida Water Management District depicts the annual high water-level period. Potentiometric levels rose 1 to 31 feet between May 1980 and September 1980 in the citrus and farming sections of southern Hillsborough, northern Hardee, southwestern Polk, northwestern DeSoto, and Manatee Counties. Water levels in these areas are widely affected by reduced pumping for irrigation and have the greatest range in fluctuations. Generally, potentiometric levels were lower than previous September levels except in Citrus, eastern Levy, and western Marion Counties where levels were 0 to 8 feet higher. (USGS)