Cape Town Inches Towards Day Zero
To the rest of the world, it will be just another day in May. But to Cape Town, the port city hanging on a peninsula at the bottom of South Africa, May 11th marks Day Zero, the day Capetonians will run out of water.
The coastal city will be the first of the world’s major cities to run out of clean water, a crisis indicative of population growth, successive years of drought and anthropogenic, or human-caused, climate change. If water usage is unable to sufficiently decline and if a rainy season does not soon reprieve the city’s reservoirs, Day Zero poses a serious threat to the city’s millions of residents.
Currently, residents are restricted to only 50 liters of daily water usage per person, while water usage for businesses and commercial interests must be reduced by 45 percent and agricultural interests by 60 percent. Additionally, about 5 percent of the city’s wastewater is treated and recycled for other purposes.
The city tracks water consumption progress publicly here, showing the city’s progress on securing alternative sources of water, the dams’ current level of water supply and the percentage of Capetonians using the required amount of daily water usage. Alternative sources of water include desalination, groundwater, and recycled water, although the high costs of such projects may lead to higher water tariffs.
In the case that Day Zero arrives, the city has constructed an emergency plan. That plan consists of planting 200 water collection points across the city, where water supplies will be distributed to residents.
At this point, residents will be confined to only 25 liters of water usage per person, although a single person may collect up to 100 liters at one of these locations to cover for family members or to distribute the amount over four days. The plan also states that the collection points will be supervised by officials and that no one will be denied access. Construction of the points will take approximately six weeks, and the emergency reserves are expected to last until the next rainy season.
The cause of the port city’s extreme case of drought is correlated to population growth, lack of rain and global warming.
Cape Town is currently home to over four million people, a number that is expected to increase in the coming years. Three years of consecutive, below-average rainfall also imperils the coastal city, a phenomenon that occurs only once in a millennium, according to a senior researcher at the University of Cape Town.
Researchers at the University of Cape Town also examined how climate change may relate to the region’s unusual aridity. Their research found that current rainfall trends may dilate into new, drier ones.
Working with the assumption that Cape Town’s climate is becoming drier, rainfall will reach lower heights, with some variability. The downward trend, researchers found, is most likely due to anthropogenic climate change. These climate models are not predictions of the immediate or specific future, but rather long-term projections of climate in the area.
A further analysis of multiple climate models also found that, although there was variability, the trend consistently pointed towards an increase of dry years and a decrease in wet years as Cape Town inches towards the end of the century.