 The North Fork is brackish along most of its length, but takes on the character of a fresh-water creek from White City northward.The headwaters of the North Fork are in the farmlands of St. Lucie County near Interstate 95 at an elevation of above sea level.In 2016, 237 billion gallons of water was discharged into the St. Lucie River from Lake Okeechobee by the U.S. Army Corps of Engineers between January and November.