Johannesburg — Residents of Africa's richest city, Johannesburg, are experiencing a severe water shortage in the middle of a summer heat wave.

The shortages, which have lasted nearly two weeks, have affected some 50% of Johannesburg Water's supply area, officials said. The South African city has a population of almost 6 million people.

Businesses have been hit hard, and several hospitals have been affected. Nurses at one medical center told local media that they were not able to wash their hands.

Mlimandlela Ndamase, a spokesperson for Johannesburg's mayor, explained that an initial problem at a key pump station occurred on March 3 after a power outage from a lightning strike.

This is not the first time the city has been without water. The city experienced regular shortages last year.

Ndamase acknowledged Johannesburg's water system is plagued by other long-term problems.

"The city does accept that there are challenges as regards to aged infrastructure, the maintenance of infrastructure, and also the need to roll out new infrastructure throughout the city," he said.

But many have blamed authorities for what they say is incompetence, and there have been some small protest gatherings.

On Wednesday, Nombuso Shabalala, a spokesperson for Johannesburg Water, acknowledged that there had been human error, too.

"Technical teams discovered a bulk supplier valve had been closed, thus restricting supply into the system," Shabalala said. "The valve has since been opened, and this has assisted with building some capacity."

Anja du Plessis, an associate professor and water expert at the University of South Africa, said, "Ineptitude, deficiency of transparency and accountability, as well as little to no political will," had exacerbated the crisis.

"The rapid escalation ... of the city of Johannesburg's water woes can be attributed to a dysfunctional and inept municipality, the lack of necessary skilled personnel, as well as the lack of financial resources, or even non-investment into the maintenance of dilapidated infrastructure," du Plessis said.

The water problems come amid issues with the nation's electricity supply.

South Africa has been mired in an energy crisis for more than a decade, and it has accelerated over the past year, with the country experiencing almost daily scheduled blackouts -- sometimes for as long as 10 hours a day.

Water tankers have been set up across the city.

Johannesburg Water says most of its systems are now in recovery.