Cape Town could be the first major city in the world to run out of water

Residents of Cape Town are in dilemma as they struggle to avert a water crisis that has hit the South African town.

In the grip of a three-year-long drought, the city is predicted to reach "Day Zero" - when its water-supplying dams sink below 13.5 percent of combined capacity today, April 21.

Within 100 days, almost all of the taps in Cape Town could be turned off.

The crisis, mainly caused by a lack of rainfall throughout the entire Western Cape Province, has led city officials to impose "level six" restrictions on Cape Town's 3.7 million people.

With dam levels currently below 30 percent, local authorities have capped water usage at 87 litres a person a day, in what have been described as the most severe restrictions of this kind ever put in place.

History of abundance

For centuries, South Africa's southwest coast has been known for its abundant natural water supplies, generated by the heavy winter rains traditionally characteristic of the region.

The city sits in a geographical bowl, making it a natural catchment area for the seasonal rains which have been relied upon to fill the dams that, since their construction in the late 19th and early 20th century, have held Cape Town's water supply.

In years of average rainfall, for example, up to three times as much of the water used annually by the city falls in the area, ensuring a plentiful supply, according to Kevin Winter, a senior lecturer in environmental science at the University of Cape Town.

But, now, such abundance is no more, as a result of less frequent, seasonal rains, which have caused water levels in the dams to fall below 29 percent of combined capacity.

"It is raining, but not sufficiently to fill up our dams," said Winter.

"As a winter rainfall region, we would expect rainfall to start somewhere around April, but that's no longer the case, it comes a whole lot later at the end of June, or in early July, if we are lucky."

According to Winter, up to three years' worth of seasonal rainfall would be required to bring the dams' water levels to pre-2015 standards.

"We are experiencing a rapid change in our weather patterns, which is increasingly evident of a climate change … There's been a very definite, sharp decline in rainfall levels in recent years," he said.

Attempts to avert crisis

In response to the dwindling water supplies, city officials are pursuing a number of solutions in a bid to avert "Day Zero", and add to the levels of water in the dams that store Cape Town's water supply.

Winter said the environmental conditions had forced "new decision-making to occur", arguing, however, that the city's longer-term planning "has been quite weak in bringing about a more integrated approach to water management", which has traditionally relied on surface water.

"Ninety-eight percent of Cape Town's water supply has come from surface water, and we haven't [historically] explored a range of other water alternatives," said Winter.

But Cape Town Mayor Patricia de Lille said the city had initiated programmes to top up levels in the dams using non-surface water sources and techniques such as drilling into aquifers, purification of seawater and water recycling.

"The city is going out of its way and working beyond its mandate to bring additional water online from various sources," she said.

"We implemented water restrictions long before we were required to do so by the National Department and had it not been for our demand management and conservation plan, the city would probably have run out of water by now."

Officials have kept water demand flat, despite a population growth of 30 percent in the last 15 years alone, added de Lille.