Only half of drought-stricken Cape Town is saving water, the City of Cape Town revealed as it appealed to residents to get on board and beat the drought.

To make matters worse, recent hot and windy weather has led to a 1% decrease in dam levels over the past week alone.

City of Cape Town Mayor Patricia de Lille said: "This summer, with the heat and wind, we can expect a steady decline going forward, so continued savings are a must."

She pointed out that only 51% of Capetonians "have put tremendous efforts into saving water", while she has appealed to the remaining 49% to help the City beat this drought.

"Your help is vital and we need you to come on board with Team Cape Town," she said.

City of Cape Town storage dam levels are currently at 36.8%, with only 26.8% of usable water remaining.

Residents' collective water usage decreased by 20-million litres, to 582-million litres per day. However, the figure is still 82-million litres above the target of 500-million litres per day.

De Lille said the City has looked at non-water-related projects across Cape Town to see which it could temporarily "postpone while protecting funds for basic and emergency services".

The City will partly fund seven additional water projects, at a cost of R2-billion, including desalination plants, aquifer projects and water recycling.

"Internally, we have made some tough decisions and we will continue to do what is in the best interests of the people of Cape Town, no matter how difficult the challenge," de Lille said.

Meanwhile, Western Cape local government spokesperson James-Brent Styan said Western Cape dam levels decreased from 36.3% last week Monday, to 34.8%.

For the same period in 2016, the province's dams stood at 59%.

Styan said in addition to Beaufort West where surface water has been depleted, Kannaland, Cape Town, Bitou and Knysna are the worst affected.

"The province remains a disaster area," he said.