WATER in Durban’s biggest storage dam has dropped to the lowest level in more than 20 years, making it unlikely that drought water restrictions will be lifted any time soon for local homes and businesses.
Umgeni Water confirmed on Friday that despite recent heavy rains along the coast, the storage level of Albert Falls Dam outside Pietermaritzburg has dropped to 20% – the lowest level recorded since 1995.
The Albert Falls Dam is one of five dams and one weir that make up the combined Mgeni system that supplies water to at least five million people in the Durban and Pietermaritzburg region.
With a storage capacity of more than 290 million m3 of water, Albert Falls is the single-biggest dam in the Mgeni system, storing one third of the system’s total water.
It is larger than Inanda dam (251-million m3), Midmar dam (235 million m3), Spring Grove dam (139 million m3), Nagle dam (24 million m3) and the much smaller Mearns Weir (5 million m3).
Umgeni Water spokesman Shami Harrichunder said latest readings show that water storage levels are Albert Falls (20%), Inanda (59%), Midmar (74%), Spring Grove (76%), Nagle 68%) and Mearns (52%).
While the combined water storage capacity of the Mgeni dams system has now reached about 54%, Umgeni requires total storage levels to reach 75% to meet normal demand.
“During times of water shortages, as is currently the case in the Mgeni system, reduction in potable water production and reduction in demand are the most effective strategies to ensure that available water lasts until the system reaches an acceptable operational level of a minimum of 75%.
“Umgeni Water has reduced potable water production by 15% and restrictions of 15% are currently being implemented in parts of eThekwini, all of Msunduzi and all of uMgungundlovu.
“In September 2017 these restrictions were extended for another year by the Ministry of Water and Sanitation in response to an application by the Mgeni system Joint Operations Committee. This application was made as a precautionary measure to ensure that there is some water available to last until the next good rains.”
In order for Albert Falls Dam to fill rapidly and reach capacity, its catchments must receive a heavy downpour for at least four days
Harrichunder said forecasts by the South African Weather Service suggest that above-average rainfall is only likely in the first quarter of 2018.
“In order for Albert Falls Dam to fill rapidly and reach capacity, its catchments must receive a heavy downpour for at least four days. Midmar and Inanda dams could fill to capacity if above-average rainfall or heavy downpours occur in their catchments for at least three consecutive days.
“Albert Falls is the largest dam in the Mgeni system, therefore, it will take longer to reach capacity.
He said the question was often asked: Why not release water from Midmar Dam to increase the level of Albert Falls?
“In reality this is an option that comes with a significant risk. If this occurs and rains do not materialise, Midmar dam could reach dangerously low levels and ultimately dead storage.”
On when water restrictions might be lifted, Umgeni Water said the entire system would have to reach at least 75% before any easing or lifting of restrictions could be considered.
Elsewhere in KwaZulu-Natal, the Pongola dam (the largest dam in the province) remains very low (at 36%), while the Goedertrouw dam near Eshowe is at 31%.
On the KZN north coast, the Hazelmere dam is overflowing at 101%, while the Spioenkop and Wagendrift dams on the Tugela River have reached 70% and 91% respectively.