The 5 mi (8 km) C-43 Caloosahatchee Canal connecting Lake Hicpochee to Lake Okeechobee allows continuous navigation from the Caloosahatchee to the Okeechobee Waterway system; oxbow lakes mark isolated stretches of the original waterway.[2] In 2013 heavy rains in southern Florida resulted in high runoff into Lake Okeechobee; rising lake levels forced the United States Army Corps of Engineers to release large volumes of polluted water from the lake through the St. Lucie River estuary to the east and the Caloosahatchee River estuary to the west. Thus the normal mix of fresh and salt water in those estuaries was replaced by a flood of polluted fresh water resulting in ecological damage.[3]