
iSIMANGALISO WELCOMES THE SECOND NATURAL BREACHING OF THE LAKE ST. LUCIA ESTUARY MOUTH
21 January 2025
The lake St. Lucia Estuary Mouth has again naturally breached to the ocean at almost the same point it breached before, next to the famous highest vegetated sand dune in Africa and the second highest in the World, the Maphelane dune. Heavy rainfall in KwaZulu-Natal in January 2025, made it possible for water coming from uMfolozi River to naturally breach to the ocean again. The uMfolozi River flood waters flowed to the St Lucia estuary where it assisted the natural breaching of the St Lucia estuary mouth on the morning of 10 January 2025. The estuary mouth had been closed for approximately four months since mid of August 2024.
iSimangaliso welcomes this natural ecological process as it is in line with the interventions in the Estuary Management Plan. iSimangaliso continues to monitor the St Lucia system, which involves the participation of other partners and stakeholders. Over the past decade, the St. Lucia Estuary mouth naturally breached on 14 April 2022, and later closed on 25 August 2024. It reopened again on the 10 January 2025, at the same location where it breached naturally in April 2022.
Observations by iSimangaliso Ecologist indicated that during the period when the mouth was open in July 2024, water levels in the St. Lucia estuary were influenced by tidal cycles from the sea at the St. Lucia bridge. However, after the mouth closed in August, tidal influence weakened leading to more stable water levels throughout August and September 2024. Recent data from automated water-level logger at the St Lucia bridge show in the graph below water levels peaking at 2.66 meters above mean sea level (MSL) on 10th of January 2025. Also, the graph shows a sudden drop in water levels in the St Lucia estuary within 48 hours after the breaching.
The re-opening of the mouth naturally will assist in addressing the topical issue of water inundation of farms that are in flood plain areas such as Dukuduku, Sokhulu and Commercial farming lands. iSimangaliso Management received concerns from these stakeholders and partners, hence iSimangaliso is continuously engaging with all affected stakeholders and interested parties to present progress and updates on iSimangaliso lake systems.
Other species, such as freshwater fish, Tilapia and Barbel, are being washed ashore as floodwaters from the St Lucia estuary flow into the Indian Ocean, mixing with coastal waters. Reeds and debris are also carried seaward by the waters of the uMfolozi River. During low tide, bank tops around the St Lucia estuary mouth are exposed, and birds such as Yellow-billed Storks, Herons, and Egrets can be observed feeding nearshore.
iSimangaliso would also like to inform members of the community to be safe when fishing/swimming/visiting the Ingwe beach which is next to the mouth as Sharks and Crocodiles have been spotted in these areas. iSimangaliso will continue to monitor the lake St. Lucia estuarine system, which is in line with the officially approved Integrated Management Plan.