Hooo-Hooo Volume 10, Nr 1 - Page 23

bosbrokkies Bush buzz Lake St Lucia’s lifeline cut off The fresh water currently flowing into iSimangaliso’s Lake St Lucia Estuary from the uMfolozi River as a result of recent rain is a godsend. With 90% of Lake St Lucia’s surface water dried up, 315km2 of the 350km2 Lake’s bed lies exposed and barren, ravaged by the drought. What little water is left is 5 times saltier than the sea in places. The highest tolerance level for estuarine species is between 2 and 3 times saltier than the sea. Fresh water in the main lake will have a tangible positive impact for the 15 000 rural households whose livelihoods rely significantly on Lake St Lucia and the sustainability of the Tugela Banks prawn fishery, not to mention the 800 hippo and 1 200 large Nile crocodile. Both of these are listed on the IUCN Red List of Threatened Species and iSimangaliso has the largest populations of hippo and crocodile in South Africa. Comparative satellite images of Lake St Lucia taken in September 2014 (left) and February 2016 (right) Between 12 and 14 March 2016, some 6.2 billion litres of fresh water entered the Lake St Lucia system, following rains both in the catchment and locally. This amounts to an average of 2.5 billion litres per day and provides an important buffer against the possibility of continued low rainfall over the next six months. Sixty percent of Lake St Lucia’s fresh water comes from the uMfolozi. These are the first significant flows of water into the system since December 2015 and it is hoped that some of the negative impacts of the drought will be reduced. Yesterday morning, fresh water forcefully pushed its way into the 20km long Narrows, and the 50km long main body of iSimangaliso’s Lake St Lucia received its first influx of fresh water from the uMfolozi River in six months. If water continues to flow into the Estuary for another two days, water could reach Catalina Bay and possibly even go further north to become aquatic habitat once again. Unfortunately, the up side in this case also comes with a down side. On 12 March 2016, iSimangaliso received notification from UCOSP that water levels had reached 1.2msl at the Cotcane measuring gauge and should begin the process of establishing a breach of the uMfolozi River out to sea. This notification follows from an interim settlement agreement that was made an order of court in October 2015, and which is valid until May 2016. Excavators have been deployed to the beach and the breach was completed yesterda