Lake St Lucia - A World Heritage Site - Lake

St. Lucia Lake is part of the St. Lucia estuarine system, the largest estuarine system in Africa. The mouth of the estuary is located about 150 miles north of Durban along the east coast of South Africa. A narrow, seven-mile long channel connects the main body of St. Lucia with the western Indian Ocean. With a maximum width of 13 miles and a length of about 40 miles, Lake St. Lucia covers an area of between 115 and 135 square miles. The depth of the lake ranges between three and eight feet.

Like other estuaries, the level and salinity of the lower reaches of St. Lucia especially varies with the inflow of freshwater from several rivers and with the ebb and flow of marine tides. In some years, the water’s salinity has risen to three times the level of sea water in northern parts of the lake, causing mass die-offs of aquatic plants and animals. 

The watershed of St. Lucia covers several hundred square miles. Besides water from the Indian Ocean that enters the mouth of the estuary, water from the Mkhuze, Nyalazi, and Hluhluwe rivers flows into the lake. In the south, the Umfolozi Swamps border the lake as does part of the Mkuze Swamps in the north. A large peninsula to the east separates the lake from the Indian Ocean. Here, over the last 25,000 years, wind and other natural forces created the world’s highest forested sand dunes that rise 600 feet. 

The entire area, which covers 842 square miles, comprises the Greater St. Lucia Wetland Area, Africa’s oldest nature reserve. Swamps and "sponge" areas along the lake, which are fed by water seeping from the dunes, pool freshwater that serves as a refuge for plants and animals when the lake water reaches high salinity.  

With its lakes, lagoons, freshwater swamps, and grasslands, St. Lucia supports more species of animal than the better-known Kruger National Park and the Okavango Delta although these areas are much larger.