If you grew up in a developed nation the chances are that you have operated under the assumption that when you turn the tap in your sinks or showers water comes out. But what happens if it doesn’t? Residents of the South African city of Cape Town are about to face the very harsh reality of living in the first city in the world to have the water supply turned off. In 10 weeks engineers will turn off water to more than one million homes as Capetown reacts to a 1-in-384-year drought.
How has it come to this you might ask? – Rapid population growth and back-to-back years of drought have seen Cape Town’s water reservoirs hit dangerously low levels. Since 1995, Cape Town’s population has grown by 79%, while water storage has only increased by 15%.
2017 was the driest year since the beginning of recording in Cape Town. In an area known as the Cape of Storms for the intense weather systems that roll in from the Atlantic Ocean, an uncharacteristic three-year dry period has placed enormous stress on the cities water supply.
The image below shows the boundary of the impressive Theewaterskloof Dam and the current water level which is forecast to reach the critical 13.5% limit on April 16th, at which point the water supply will be cut to Cape Town.
Cape Town is one of the wealthiest cities in Africa, and as a result residents are experience the pressure of the incoming Day Zero very differently depending on their level of wealth. Affluent residents are tapping into groundwater by installing deep groundwater wells and are avoiding water restrictions all together. Less fortunate residents are being forced to get creative with their water use, with some people reusing washing machine water until it’s too dirty and subsequently using it to flush the toilet.
The important lesson for the rest of the world watching the crisis unfold in Cape Town is that the past is no longer an accurate guide to the future. Now is the time to look at the way we use water and consider how resilient our supplies are to a changing climate.
In many ways we are facing a similar problem right here in Perth. South-West Western Australia is experiencing a long-term drying trend. With annual rainfall declining by more than 15% since 1980 and the population doubling from just over 1 million in 1986 to 2.04 million in 2017 significant strain has been placed on our water supply. In 2016 the combined metropolitan dams reached as low as 26% capacity.
To manage increasing demand the Water Corporation has diversified the water sources, focusing on climate-independent water sources. In 2005-2006 the water supply in Perth was split down the middle, with 50% of water being supplied from surface reservoirs and the remaining 50% from groundwater. Since then two desalination plants have been built which provide close to 50% of Perth’s water supply needs. In 2014-15 as little as 17% of water was supplied from surface water reservoirs.
Unfortunately for Cape Town the plans to diversify water supply, including the construction of desalination plants, was set for 2020. The city has been left scrambling for water, imploring residents to use less than 50 litres of water per day (for those playing at home that is roughly equal to a 5 minute shower).
Emergency services are currently developing plans for the disruption of supply, which will include the establishment of 200 water collection points scattered around the city to ensure the legally guaranteed minimum of 25 litres per person per day within 200 metres of every citizen’s home.
The cost to the nation’s economy and well-being is difficult to predict, for now all we can do is hope Cape Town can manage until the start of the rainy season in May.