The Nelson Mandela Bay Municipality will be opening communal taps on Saturday in a bid to prevent one of its dams from running dry by Tuesday.

The municipality said it would reduce consumption from Churchill Dam on Sunday, from 60 megalitres daily, to 25 megalitres. At the current consumption rate, the dam would have only enough water to last until Tuesday, pushing the residents of four towns closer to Day Zero.

The reduced supply is likely to add another five days of water supply.

However, throttling the supply will see the southern and western suburbs of the metro, including parts of New Brighton and KwaZakhele, experiencing intermittent water supply.

The municipality said in a statement, "The metro will supplement water supply in these areas with standpipe collection points, rainwater tanks, and water tankers. Initially, nine of the 24 communal water collection points will be activated to operate."

The measures are expected to be in place for seven days.

The municipality is currently not extracting water from Impofu Dam while the barge is being relocated. This has seen Churchill Dam carrying most of Impofu Dam's shortfall, and it is now also seriously depleted, the municipality said. Once the barge is moved, Impofu dam will begin yielding 30 megalitres of water a day.

However, the municipality has warned that consumption levels remain "unrelenting" and high, at 60 megalitres over the daily target of 230 megalitres.

In the meantime, the municipality will increase its citywide installation of water demand control systems and users have been encouraged to cut their water consumption to less than 50 litres per person per day.