 The District's responsibilities have expanded to include managing water supply and protecting water quality and the natural systems — rivers, lakes, wetlands and associated uplands.The District encompasses approximately in all or part of 16 counties in west-central Florida including Charlotte, Citrus, DeSoto, Hardee, Hernando, Highlands, Hillsborough, Lake, Levy, Manatee, Marion, Pasco, Pinellas, Polk, Sarasota, and Sumter counties, serving a population of more than 5 million people.The District is divided into eight basins, which are based primarily on watershed or geographic boundaries.