Durban - Concern has been raised about the water levels at Albert Falls Dam which is one of the main sources of water supply to the eThekwini region - even after the rain experienced throughout the province recently. The dam is currently at 27.39 percent.
“If Albert Falls Dam reaches dead storage then all that is left in it is silt. The eThekwini region could be negatively affected with a reduced amount of water available. To prevent the possibility of dead storage, Umgeni Water has reduced potable water production by 15 percent at water treatment plants in the uMngeni system and mandatory 15 percent water restrictions are in place,” said Shami Harichunder of Umgeni Water.
The Sunday Tribune revisited four dams, Midmar, Albert Falls, Hazelmere and Inanda to assess levels of water to find out if the three-day downpour that left a trail of destruction, including six people dead, had any impact on the drought.
Midmar is currently at 45 percent, the lowest it has been in 2 years.
Harichunder said that 55mm of rainfall was recorded at Midmar from last Sunday to Tuesday.
“This has only had the effect of stabilising the level of Midmar at 45 percent. Water is transferred from Midmar into Albert Falls Dam and water is normally released from Albert Falls Dam into Nagle Dam. The low level of Midmar has influenced the decision against release of large volumes of water into Albert Falls Dam,” he said.
Hazelmere dam is at 50 percent. The rainfall and transfer of water from uThongathi River to Hazelmere Dam through an emergency scheme resulted in the level of this dam increasing by 5 percent.
“While this represents a slight improvement in water resources, it is not sufficient to meet the pre-drought demands of iLembe District Municipality and eThekwini Metro. Therefore, reduction of 50 percent in potable water production at Hazelmere Water Treatment Plant and mandatory water restrictions of 50 percent on consumers who get water from this water treatment plant will remain in place,” Harichunder said.
Inanda Dam had 87mm rain in the same period; the level of the dam remains unchanged at 68.33 percent.
He said much of the rain fell outside the catchment areas of dams.
“This did not translate into run-off. Instead it made its way into drainage systems and the sea. The best source of feeder for dams is rainfall in their catchments.
“It takes at least five days for run-off water from rain to make its way into a river system and ultimately into a dam. By early next week the levels of these dams could change once all the run-off water has reached them,” Harichunder said.
In May the levels of dams were:
Midmar: 45.78 percent
Inanda: 76.61 percent
Albert Falls: 32.85 percent
Hazelmere: 46.71 percent.
Sunday Tribune