A set of power failures at Rand Water last month is still affecting water supply to Johannesburg and Tshwane.

The water entity - which purifies and distributes bulk water to municipalities, businesses, and residents in Gauteng - suffered a series of outages and trips in June at its Vereeniging and Zuikerbosch water treatment plants as well as at the Palmiet, Eikenhof and Mapleton booster pumping stations.

As reservoirs struggle to recover, some residents have been intermittently without water for days.

On Sunday, Johannesburg Water, the city's bulk water purchaser and distributor, told clients in Midrand there was still an issue with the supply from Rand Water. 

"Johannesburg Water customers in the Blue Hills and Sun Valley areas … are affected by no water supply due to low supply from Rand Water.

"This is because the bulk water supplier is still struggling to recover after multiple power failures.

"According to Rand Water, balancing of the systems is still being done, and as a result, there will be challenges of inconsistent supply."

Rand Water's Brakfontein reservoir has also recently been affected.

It feeds a reservoir in Tshwane that supplies Johannesburg Water's customers in Blue Hills and Sun Valley in Midrand.

"At the moment, there is no water coming into Blue Hills and Sun Valley from Tshwane because the city is not getting enough supply from Rand Water.

"As Rand Water recovers its systems, some of the areas within municipalities are therefore likely to experience low water pressure to no water during the recovery of the system."

Johannesburg Water tankers have been placed in the following areas to mitigate the issue:

• Summit Road next to Spar SaveMor.
• Blue Hills Shopping Centre.
• Blue Hills Ext 15 & 32 complexes.
• Summit View Estate, opposite the Blue Hills Shopping Centre.

The entity said there was no estimated time of recovery.

Some residents in Midrand still have not had water.

On Monday afternoon, Johannesburg Water said its reservoirs and towers were stable across the city.

At the same time, the Commando System, which comprises the Brixton, Hursthill and Crosby systems, continues to gain capacity.

"At the Hector Norris pump station, which supplies parts of the Johannesburg CBD, we have implemented a backup power supply due to the current City Power outage. Customers should not be affected by an outage at this time.

"However, it's important to remember that water is a precious resource, and we need to continue using it wisely even as the situation improves.

"We, therefore, urge residents to assist us in efforts to preserve water, and we appreciate the cooperation," the entity added.

The City of Tshwane reiterated this message.

On Sunday, it told residents unless they heeded the call to use water sparingly, the current outages would worsen, and more areas would be affected.

Rand Water revealed the City had exceeded its water consumption by 15%.

"The City of Tshwane has been experiencing challenges of inconsistent water supply following a number of power failures and trips [at Rand Water in June]."

On Monday, there was an improvement in the Garsfontein and Laudium reservoirs which had recovered from 20% and empty on Sunday to 90 and 54%, respectively, on Monday afternoon.

But the City warned there were still areas struggling with water supply.

These include the Mooikloof, Klapperkop, Mnandi, and Lotus Gardens reservoirs in Centurion, which are at critically low levels or empty.

"The City's technical team is engaging with Rand Water for intervention so that water supply can be restored to all affected areas."

Water tankers will be deployed to the affected areas in regions 1, 2, 3, 4, 6, and parts of 5.

Meanwhile, Rand Water and the Water Research Commission are hosting the 91st Meeting of the Scientific and Technical Council of the African Water and Sanitation Association in Gauteng until Wednesday.