A series of severe thunderstorms brought heavy rainfall and flooding to southwest-central Florida during June 21-24, 2003. The storms and resultant precipitation were caused by a late-season stationary cool front (Canadian high pressure ridge) that combined with tropical moisture from the Gulf of Mexico to produce above-normal rainfall over already saturated ground (National Weather Service, written commun., 2003). Rainfall totals at U.S. Geological Survey (USGS) streamflow-gaging stations ranged from 9 to 17 inches and record flooding occurred in parts of Charlotte, De Soto, Hardee, Manatee, and Sarasota Counties, Florida (fig. 1). The floods caused $11.3 million in damage to public and private property, including damage or destruction of 119 homes (Binette and Saewitz, 2003).
Western De Soto, western Hardee, Manatee, and Sarasota Counties are drained by the Horse Creek, Manatee River, and Myakka River systems. Water in these watersheds flows southwestward to Charlotte Harbor and the Gulf of Mexico (fig. 1).