Cape Town on Wednesday announced a crackdown on splashing and surfer shorts at the city's swimming pools in a bid to save water as a fierce drought plagues Southern Africa.

Most pools in the city will also be closed on weekdays to eliminate the need to clean them daily, which is expected to save 680,000 litres (180,000 gallons) of water every day.

Southern African nations are reeling from a two-year drought which has affected over 40 million people, UN figures show.

"With pools only staying open on weekends, only one backwash per week will be needed. Showers at pools will be switched off and splashing in pools will also be monitored and restricted," the city said in an emailed statement.

Authorities are also cracking down on swimmers wearing surfer-style shorts which tend to absorb more water than the skin-tight speedos.

"Only normal bathing costumes may be worn when swimming at public swimming pools as significant water can be wasted just by swimming in casual clothing," it said.

Jean-Pierre Smith, a member of the city's safety and security committee, said that the situation was "not ideal".

"But I trust the public can appreciate the severity of the situation and will support this measure.

"Frankly, a short-term sacrifice like this is a small price to pay," he said.