FOLLOWING the completion of a study aimed at finding long term solutions to improve the hydrological and ecological functioning of the Lake St Lucia system, work to remove the artificially created ‘island’ of sand in the mouth area will begin in the new year.
According to the iSimangaliso Wetland Park Authority, its Global Environment Facility-funded (GEF) study shows that the sand and ‘spoil’ placed in the estuary mouth area through 50 years of dredging continues to impede the flow of the Mfolozi River into the Lake St Lucia system.
A geotechnical survey completed last month provided information on the size, moisture content and roughness of the soil and other material in the dredger spoil. This information helped finalise the method to be used to remove the sand.
iSimangaliso CEO, Andrew Zaloumis, said, ‘iSimangaliso, with Ezemvelo KZN Wildlife, is striving to recreate the wholeness of nature and to strengthen Lake St Lucia’s resilience’.
In 2012 iSimangaliso implemented its strategy, by way of a spillway, to let the Mfolozi River rejoin the estuary in a bid to restore the functionality of the estuary system.
‘Lake St Lucia was effectively drying up and the system degrading,’ said Zaloumis.
‘Since the Mfolozi River rejoined Lake St Lucia in 2012, there have been compelling indications of ecosystem recovery despite receiving lower winter and spring rainfall.
‘Lake and salinity levels are well within the range tolerated by estuarine plants and animals.’
According to a report issued by iSimangaliso, while water levels have dropped since 1 August, with Charters Creek recording a drop of 28cm, the lake water levels are just above mean sea level.
The shorelines in the upper reaches of False Bay and the Nibela Peninsula reportedly remain ‘inundated’.
While the last six months saw a reduction in water exchange through the spillway, the marine influence was apparent in high spring tides during early winter.
The report also states that the Mfolozi River mouth is likely to move northwards in response to a stronger flow from increased summer rainfall.
‘There is also the possibility of the Mfolozi breaching the barrier towards Maphelane or removing it completely if a strong flood occurs’.
