14 Oct 2018

River reeds sprouting from the Shashe and Tati rivers, which have resulted in river sand becoming hardly invisible, have over the years been a common sight.

In an effort to establish the causes and implications of the trend, we interviewed the Department of Water Affairs regional manager, Mr Lawrence Modo.

Mr Modo said the first major possible cause was the depletion of sand over the past years as a result of excessive illegal sand mining.

“This phenomenon has resulted in the exposure of the river bed hence the emergence of different types of vegetation on the river bed. Some sand mining pits have become ponds or pools and hold water for some time and give rise to the growth of these vegetation plants,” he explained.

Mr Modo said the second possible reason was the waste water discharged into the river which brought along nutrients such as nitrates and phosphates.

He said the nutrients when in excess gave rise to the eutrophication process, a process that causes reeds to grow en masse.

Mr Modo said the development of reeds and other plants would in the long run disturb the river flow and cause flooding.

He said the reeds could be a safe haven for criminals. He said the marshy pools or ponds could also become a breeding ground for mosquitos and other insects. He added that the reeds could also diminish available water resources in the river sand.

“The department in 2015 through partnership with Resilience in the Limpopo River Basin Programme (RESILM) and the established Tati River Management Committee carried out a campaign to clean up the river including the removal of reeds. The exercise was only successful on the part of litter picking,” he said.

Mr Modo explained there was a challenge of lack of specialised resources to be used for the reeds removal. He said various control measures were discussed and that they recommended control measures even though it was labour intensive. ENDS