Okeechobee Mudfest, Florida, United States

During construction of the dike, earth was excavated along the inside perimeter, resulting in a deep channel which runs along the perimeter of the lake. In most places the canal is part of the lake, but in others it is separated from the open lake by low grassy islands such as Kreamer Island. During the drought of 2007-2008 this canal remained navigable while much of surrounding areas were too shallow or even above the water line. Even when the waters are higher, navigating the open lake can be tricky, whereas the rim canal is simple, so to reach a specific location in the lake it is often easiest to go around the rim canal to get close then take one of the many channels into the lake.
Environmental concerns
In 2007, during a drought, state water and wildlife managers removed thousands of truckloads of toxic mud from the lake's floor, in an effort to restore the lake's natural sandy base and create clearer water and better habitat for wildlife. The mud contained elevated levels of arsenic and other pesticides. According to tests from the South Florida Water Management District, arsenic levels on the northern part of the lake bed were as much as four times the limit for residential land. Independent tests found the mud too polluted for use on agricultural or commercial lands, and therefore difficult to dispose of on land.