By Sanku Tsunke
The world has seen how the Cyclone Eloise ravaged some parts of southern Africa, in Mozambique, Zimbabwe and Madagascar and left thousands of people homeless due to the floods.
Last week, we have witnessed how Cyclone Eloise moved inland, in Mpumalanga, Limpopo and Free State provinces. We also saw it, but not as hard, on the coast of KwaZulu-Natal. Although the storm was not devastating in strength like in Mozambique, it has caused damage to some parts of Limpopo, Mpumalanga and KwaZulu-Natal. The heavy rains and floods resulted in damaged houses and roads, and trees being uprooted.
Despite all these tragedies in the country, the unremitting rain has brought some relief to the country’s dams. In Mpumalanga, the Sand Dam in the Witklip River saw a huge increase of water levels from 74% to 104% in a matter of days. Blyderivierpoort Dam based in Blyde River has also seen a drastic improvement from 101% to 105.2%. The province’s dams have an average improvement of 67.7% to 72.1%.
Other provinces such as Free State, Limpopo and KwaZulu-Natal have witnessed a rise in their dam levels too, and this can be attributed to Cyclone Eloise. This is a bitter-sweet occurrence, because dams in some parts of the country were dwindling at a rapid rate a few weeks ago.
Since the heavy rains that resulted in the flash floods in some parts of the country, the Department of Water and Sanitation has prepared a plan to manage the floods – a combination of structural and non-structural methods.
Some existing water infrastructure such as the Vaal Dam, Gariep Dam, Vanderkloof Dam and Bloemhof Dam have gated spillways and built-in flood retention capacity. This combination makes it possible to weaken and to capture peak flood volumes or to pre-emptively release reservoirs rapidly.
The main objectives of flood management in order of priority are to ensure the safety of the structure and therefore human life; minimisation of damage due to high water levels; and ensuring that the dam is 100% full at the end of the flood. This flood management or preparedness is governed by the National Water Act 36 of 1998.
Sanku Tsunke is from the Department of Water and Sanitation.
The Star