Load-shedding means extensive water supply cuts in KZN

Hundreds of thousands of KwaZulu-Natal residents do not have access to water during and after load-shedding, Umgeni Water said on Monday.

Umgeni Water spokesperson Shami Harichunder said Eskom’s critical generation shortage and announcement about load-shedding over the festive season was affecting the supply of drinking water to municipalities within Umgeni Water’s service area.

“As a consequence, hundreds of thousands of consumers within the uMgungundlovu municipality, Msunduzi municipality, iLembe municipality, Ugu municipality, Harry Gwala municipality, King Cetshwayo municipality and eThekwini metropolitan municipality are unable to receive drinking water for the duration of load-shedding and often longer as supply infrastructure recovers from the effects of power outages,” he said.

In the Umgeni system, which is the largest in the province, the areas worst affected by water supply failures through power interruptions were Vulindlela, Mpophomeni and Hilton, all high-lying and dependent on the Howick West reservoir for potable water transferred through a system of pumping.

“Other areas that do not receive water during load-shedding are KwaHaza, KwaChief and Mashingini. In Impendle, all areas are affected while in the Mpofana system, Bruntville is often starved of water supply when power disruptions occur.”

“The Midmar pump station and the Midmar water treatment works are excluded from load-shedding so conveyance of raw water and its treatment are not affected. When power outages occur, downstream Millfalls reservoir is able to receive water from the Midmar water treatment works and transfer it to the Howick West reservoir.”

“The water remains in the Howick West reservoir until power supply is restored. Consequently, the reservoirs of uMgungundlovu municipality and Msunduzi municipality in Vulindlela are unable to supply water to consumers in the vast area of Vulindlela. Water is pumped from the Groenkloof reservoir in Hilton to Vulindlela. Hilton is affected when power outages occur,” said Harichunder.

He said the reservoir in Richmond was also reliant on the Midmar water treatment works supply zone.

“It is affected because water has to be pumped there as well. Areas within Richmond that are affected by no water supply are Ndaleni. Nhlazuka and Mbutshisweni. In the Mkhambathini area, Ukhalo is known to be unable to receive water.”

Harichunder said with load-shedding creating power supply cut-offs in some instances for up to six hours per day, it took at least an hour for the supply mechanisms in the bulk and reticulation networks to return to full functionality.

“In the meantime, what little storage remains in reservoirs begins emptying and there is no accompanying replenishment. This leads to supply interruptions to consumers.”

“From the Midmar water treatment works, water is gravity fed to the eThekwini metro via Point M in Umlaas Road.

“The eThekwini metro is able to receive full supply during load-shedding for distribution to areas including Mid-Illovo, Eston, Umbumbulu and Hillcrest.

“The DV Harris water treatment works, situated in the outskirts of Pietermaritzburg and part of the Umgeni system, continues to take the brunt during power shut-offs. This plant supplies Umgeni water’s seven reservoirs in the uMshwathi region through pumping. All the receiving bulk and reticulation reservoirs in uMshwathi are left without water. Therefore, consumers in Swayimane, Trust Feed, Efaye, Ozwathini and Wartburg are unable to receive water,” Harichunder said.

He said a stand-by diesel-powered generator at Maphephetheni water treatment works in Inanda was used during power supply interruptions to ensure continuous supply of potable water. However, that led to a significant increase in diesel use and cost.

“In the Durban Central region, the Durban Heights water treatment works has two incomers, one of which has been excluded from load-shedding. The exemption includes all production units, shaft pumping and the KwaDabeka pump station. The section that has not been excluded affects feed to the Pinetown pump station, which means no pumping can occur.”

“The pump station at Inanda Dam has two sources of energy, namely a stand-by pump and Hillcrest and Mzinyathi that supply the eThekwini metro electricity department. Inanda Dam is one of two sources of raw water supply to the Durban Heights water treatment works in Reservoir Hills, Durban. The other is Nagle Dam in Cato Ridge, from where water gravitates into channels and then into four aqueducts. This means the Durban Heights water treatment Works has an assured supply of raw water from Inanda and Nagle dams and available power at all times to ensure the plant continues to produce potable water.”

The Inanda pump station was exempted from load-shedding.

“The Durban Heights water treatment works supplies reservoirs in the north, south, central and inner west regions of Durban. The interconnected Wiggins water treatment works in Bonella, Durban, has been exempt from load-shedding. This system supplies potable water to central Durban. It also augments the Amanzimtoti water treatment works through a system of gravity feed and pumping. At times of load-shedding, transfer of water from the Wiggins works to the Amanzimtoti water treatment works is interrupted, exacerbating the deficit that already exists at the Amanzimtoti water treatment works.

“Parts of the middle south coast served by Umgeni Water, from Amanzimtoti in eThekwini to Umzinto in Ugu, remain constrained. Load-shedding results in downtime of the South Coast augmentation booster pump station, which is situated between Wiggins and Amanzimtoti and is used to pump water to the Amanzimtoti water treatment works. Supply to eThekwini metro is from the Wiggins works through reservoirs and the South Coast augmentation booster pump station and is supported by the Amanzimtoti water treatment works,” said Harichunder.

He said reduced volumes of potable water caused by power outages at the booster pump station varied between 20% and 30% — or on average a deficit of between 30Ml/d and 40Ml/d, depending on the stage of load-shedding.

“Higher stages of power outages cause high levels of water shortages. This results in reduced supply to eThekwini metro for reticulation to Amanzimtoti and similar reduction in supply to Ugu municipality.”

“The Umzinto water treatment works loses approximately 30% in potable water production during load-shedding. This is caused by reduced abstraction volumes of raw water from the Umzinto and EJ Smith dams because pumps are unable to work. When load-shedding occurs, generators are used in what becomes a slow and long process that often produces yields less than the required volumes. A similar situation prevails at the Mtwalume water treatment works, which also experiences reduced volumes of potable water produced due to reduced volumes of raw water abstracted,” Harichunder said.

Mid-south coast systems’ full recovery time post-load shedding was, on average, two hours.

“The Mhlabatshane water treatment works has a back-up generator which allows it to operate when power is switched off by Eskom or if there is power failure due to problems in the network. The cumulative effect is reduced sales revenue while costs are rising sharply through increased use of diesel,” said Harichunder.

The lower uMkhomazi bulk water supply scheme, under construction in Cragieburn, Umkomaas and 20km northwest off Scottburgh, would in the near future alleviate water supply constraints in Amanzimtoti to Hibberdene through provision of 100Ml/d on a sustainable basis.

“The Hazelmere water treatment works in the north of Durban receives its water from the Hazelmere Dam through gravity feed. The water is treated at the plant and supplied to eThekwini metro, iLembe municipality and Siza Water. The potable water production process comes to a standstill when electricity supply is interrupted through failures or load-shedding. The potable water already produced remains in the onsite reservoir and is only distributed when electricity supply is restored.”

“There are five bulk distribution systems within the Hazelmere supply area. All are dependent on electricity to power the pumps. The systems are Ndwedwe, Verulam/Grange, La Mercy, Avondale and Waterloo,” said Harichunder.

The Ndwedwe system had backup power supply.

“The Ndwedwe system has five pump stations, four of which have backup generators to run the pumps, which makes it possible to supply water from Umgeni Water’s reservoirs during load-shedding and unplanned power outages. Recently diesel theft has occurred, which could pose a risk to functioning of some back-up generators if it continues.

“The water treatment plants in the King Cetshwayo district operated and managed by Umgeni Water are affected during power stoppages because they do not have stand-by generators. This means the potable water produced cannot leave the plants and the Water Services Authority does not have adequate water to distribute to consumers in Eshowe and surrounding areas,” said Harichunder.

He said the Ixopo water treatment works, within Harry Gwala municipality, remained fully functional because it used a diesel-powered generator during load-shedding.

TimesLIVE