After being starved for decades, water levels in South Africa’s largest estuarine lake are rising rapidly after some of the heaviest spring rains in 15 years.

A spokesman for the iSimangaliso Wetland Park said at the weekend that records showed that Lake St Lucia had received the highest rainfalls in September and October since at least 1997.

As a result, the salt water levels in the northern section of the lake had dropped almost overnight.

In late August, the salinity level at Lister’s Point in False Bay was almost 100 parts of salt per thousand parts of water – almost three times as salty as sea water (35ppt).

However, the salinity level in this northern section of the lake dropped rapidly in a matter of days in early September to just above 35ppt and by early November the salinity level was lower than sea water.

Although the final rainfall figures for November were not available, scientists said the water level in St Lucia had been increased significantly – partly as a result of the heavy spring rains, but also due to the recent re-linking of the lake to the Umfolozi River.

In June this year ecologists dug a narrow channel between the mouth of the Umfolozi River and St Lucia estuary to rejoin the two water systems for the first time in 60 years. The mouths were initially separated to avoid back-flooding of low-lying sugar farms.

http://www.iol.co.za/news/south-africa/kwazulu-natal/lake-st-lucia-loses-salinity-due-to-rain-1.1434686