Durban - UMGENI Water says they have engaged Eskom to discuss the possibility of excluding water treatment plants from load shedding to prevent the serious impact that interrupted electricity supply has on the provision of water to consumers.
Shami Harichunder, the corporate stakeholder manager of Umgeni Water, said the abstraction and transfer of raw water to water treatment plants and supply of drinking water in bulk to municipal reservoirs have been affected to varying degrees by ongoing Eskom load shedding.
Harichunder said it was not possible to use back-up or stand-by power systems at large plants, including Midmar in Howick and Durban Heights in Durban, because of the high volume of electricity required for large-volume potable water production.
“The treatment process of raw water at water treatment plants and transfer of treated water to the reservoirs of Umgeni Water’s municipal customers also require electricity,” he said.
He said they met with Eskom on Monday to discuss the matter.
A significant amount of water, 503 million litres per day, is supplied to eThekwini by Durban Heights Water Treatment Plant together with the Wiggins Water Treatment Plant he said.
Harichunder said Umgeni Water staff have indicated they are able to manage stage 2 load shedding with existing procedures and processes.
“However, the expectation is that higher levels of power supply interruptions is likely to result in significant supply interruptions in systems that are constrained and where demand exceeds resource availability.”
He said the transfer of water from Mearns Weir and Spring Grove to augment resources in Midmar Dam in the Upper Mgeni system had also been affected by load shedding.
He said consumers have been affected by interruptions in the pumping of drinking water from Howick West to Hilton and to Vulindlela and Mpophomeni.
“Storage reservoirs that supply Vulindlela and Mpophomeni have, at times, run empty, resulting in supply failures to the municipality and ultimately an impact on consumers.”
In Durban, the pumping of raw water from Inanda Dam to Durban Heights Water Treatment Works had also been affected by load shedding
“Storage in Reservoir 2 at Durban Heights has also been drawn down, the impact of which is noticeable in the municipal distribution network.”
He said Umgeni Water area managers have reported that in the past week they had seen reduced volumes of abstracted raw water from dams being treated to drinking water quality.
In one instance Harichunder said electricity interruptions on the South Coast, where demand for water already exceeds supply, production had at times been between 50% and 60% of the volumes that were generally produced.
“This ultimately translates into reduced volumes of drinking water that is supplied to the customer. Reduced volumes produced, and supplied invariably results in reduced revenue. Some reservoirs on the South Coast have reached critically low levels.”
In addition, Harichunder said load shedding would have a significant long-term impact on Umgeni Water’s s infrastructure and in recharging of systems after electricity downtime.