After years of severe drought, Cape Town, South Africa is running out of water — and Day Zero is fast approaching.

That’s when the municipal dam’s water level will fall below 13.5% and cause the city’s government to turn it off its water supply, unless residents and businesses across the city begin rationing their consumption by April 22.

For individual residents that means using no more than 87 liters per day — the equivalent of a four-minute shower. The government also instructs businesses to cut back on their average water use by at least 45%, according to the government’s water management website.

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So far only about half of Capetonians have complied with the new rules, putting Cape Town on track to become the world’s first major city to run out of water.

“It’s not an impending crisis — we’re deep, deep, deep in crisis,” Free State University environmental professor Anthony Turton told The New York Times.

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Worldwide, roughly 2 billion people lack access to clean water, including more than 750 million people in sub-Saharan Africa. Water crises related to droughts, conflicts and contamination have affected regions across the world, including California, Somalia, and Syria.

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ICYMI: Cape Town experiencing severe drought due to abnormally dry weather; possibility of extremely low water supply within next 4 months https://t.co/Epbtj7D9ki@NYT

— Phase Zero Project (@PhaseZeroNA) January 8, 2018

According to the Cape Town’s municipal water website, which provides water-rationing instructions, the city’s dams are less than 30% full and the city has a long way to go to secure alternative water sources, such as desalination of seawater.

Though the current drought will eventually end, Cape Town University’s Climate System Analysis Group predicts that the region will experience similarly dry years more often, which would further jeopardize the existing water supply.

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While individual water rationing remains important, residential water use pales in comparison to industrial use. Worldwide, agriculture accounts for 70% and industry, 20% of all water use.

As Cape Town waits for rain, the city continues to urge its industries, residents, and visitors to take the threat of a water shutdown seriously.

But not everyone is listening.

“I think it’s kind of like, you know when you have a health scare, so you just ignore it till you’re dying on the ground?” blogger Natalie Roos told The New York Times. “I think that’s pretty much where we’re at.”