Breathing new life into the lake

WORK is about to start on the rehabilitation of the St Lucia Estuary following the signing of a contract for the project to start within the next few months.

The opening and closing of the St Lucia Estuary and Umfolozi River mouth has been an on-going debate over many years.

Following extensive research by Ezemvelo KZN Wildlife and iSimangoliso staff over the last five years, a solution appears to have been found.

This research culminated in a R10-million contract to promote the linking of the two systems being signed on Tuesday.

Cyclone Engineering’s Gerrit van Ryssen and iSimangoliso Wetland Park CEO Andrew Zaloumis signed the contract which will allow for an estimated 97 000 cubic metres of dredge spoil to be pumped into the inter-tidal zone.

The contractors will be removing the sand accumulated over the years from dredging operations using water cannons and pumps.

A mud slurry will be deposited into the sea.

Site establishment is expected to take two months and the initial project should be completed by the end of June.

A further R20-million has been secured, which should go a long way in removing a large section of the dredging spoil.

Natural system

The slurry will be deposited into the tidal zone, which would receive the deposits under ‘normal’ conditions.

The opening of the link between the Mfolozi River and St Lucia Estuary will open up the system to receive fresh water.

This will stabilise the salt levels in the Lake St Lucia system.

When flooding occurs, the mouth will open to the sea and as sand is deposited from wave action from the south, it will again close.

Early aerial photographs show that the Umfolozi River is a critical component of the St Lucia system.

Of the four rivers feeding the system from the north, (uMkhuze, Mzineni, Hluhluwe and Nyalazi), only the uMfolozi River, with 60% of the total catchment, feeds from the south.

This fresh water from the south is a crucial factor affecting the salination of the St Lucia System.