THE people of Cape Town have spent recent years praying for rain. It has not come often enough. Lawns have faded to brown and swimming pools have gone dry. The dams that hold the South African city’s water supply are now at just 26% of capacity. Officials warn of the likelihood of a Day Zero, when the level at the dams will drop below 13.5% and the city’s water supply will have to be turned off. (The 13.5% level is set by the city, which notes that it may be hard to extract any water at all if it falls below 10%.) Unless things change, Day Zero is due to fall on April 16th, though earlier estimations suggested both April 12th and April 21st. It will make Cape Town the world’s first big city to run dry. Residents will have to queue to get water rations—25 litres per person per day—from collection points under armed guard. Already water pressure from the taps has been throttled. Residents have grown used to short showers, and loos are seldom flushed. Hotels have removed bathtub plugs from rooms. How did this happen?

Cape Town is South Africa’s second-biggest city, with a population of around 4m. But the development of new water supplies has not kept pace with population growth. And the situation has been pushed to crisis point by the weather. Cape Town has seen little rainfall in recent winters, when most of it comes. According to Piotr Wolski, a researcher with the University of Cape Town’s Climate Systems Analysis Group, the drought in the city’s water-catchment area between 2015 and 2017 was of a once-in-300-years magnitude. The city mayor, Patricia de Lille, has also blamed wasteful residents who fail to observe water-use limits. According to the city, only 41% of Capetonians complied with these targets when they stood at 87 litres of water per person per day. This target has now been cut to 50 litres per person, in order to reduce collective daily consumption to 450m litres. Under a punitive new tariff structure, people who use huge amounts of water will pay dearly.

A good rainfall, combined with adherence to that 50-litre target, could stave off Day Zero until the much-hoped-for arrival of winter rains in late April or early May. New water sources are being rushed to completion, including desalination plants and projects to extract water from aquifers. Many residents wonder how much of the crisis is to be blamed on the weather, and how much on a lack of government planning. Cape Town and the Western Cape province in which it sits are run by the Democratic Alliance (DA), a party that prides itself on clean and efficient governance. But concerns were raised long ago about the city’s future water supply. Problems have been exacerbated by a local leadership crisis, with the DA seeking to remove Ms de Lille over corruption allegations (which she denies). And further issues arise from tensions in the relationship between the DA and the African National Congress (ANC), which governs nationally. The DA has accused the ANC of failing to fund water projects.

As Day Zero approaches, confusion is growing about how this waterless city might work. Some city officials worry about the possibility of disease spreading in tandem with the reduction in hand-washing and basic hygiene. South Africa is already dealing with a serious outbreak of food-borne listeriosis. Many businesses will have to shut, though the city says it will keep water flowing to high-density business areas, as well as hospitals, schools and poor townships. Tourism to Cape Town, a bright spot in an otherwise sluggish South African economy, could suffer. The other main industry in the Cape, agriculture, is already ailing. There could also be political fallout for the DA, which is seeking to challenge the ANC on a national level in next year’s polls. All of this could change, should the rain return.