Day Zero—currently predicted to be April 12 by local officials—is the exact day when the city of Cape Town in South Africa will run out of water.

This may sound like a far-fetched, dystopian hellscape. But Cape Town has been dealing with ongoing drought for three years now because of a host of factors, including poor government planning, all aggravated by climate change. The dams and reservoirs that supply the city of an estimated 4 million people are running dangerously low. Already under water use restrictions, residents will soon have to collect rations of water piped into the city at centralized points, protected by armed guards.

Meanwhile, some entrepreneurial folks in the area seem to have looked for opportunities to make cash in the drought, as reporter Aryn Baker mentioned in Time. On sites like Gumtree and Junk Mail, South Africa’s Craigslist-like online classifieds, dozens of vendors have started selling water, water tankers, water pumps, and filters to meet the demand where the government has not.

On Gumtree, several services advertise water deliveries for drinking, storing, or filling up swimming pools. The vendors appear to be small companies or individuals, pumping water from boreholes or rain dams and delivering thousands of liters in tankers and milk trucks. One of them, Water@Langerbergkaas, was started just last month, by two brothers about 140 miles from Cape Town, according to their website.

The existing ads selling water on Gumtree date back to November.

Screenshot from Gumtree.

One post on Junk Mail, from a vendor in Cape Town, directly addresses the crisis: “Drought getting you down?” it reads. “Let us help you by installing a water tank or two in your house or small holding.” Another says, “Beat the water restrictions,” and advertises a water tank and firewood.

There have also been postings for water tankers—trucks for moving water—in other cities like Johannesburg and Pretoria, and water purifiers promising reverse osmosis technology.

The prices of the services vary widely. Some price their services at 1.7 South African rand per liter ($.14) and others at .5 rand per liter ($.04). One Gumtree vendor, who asked to remain anonymous, told me via WhatsApp that he has been supplying water for 65 cents per liter for the past four weeks, which he sources from Klapmuts, a town in the Western Cape province, which includes Cape Town. He said he applied for a water license to be able to do this.

Are these actually solutions? It depends. Even if someone purchases a tanker, getting the water from bottling plants can be illegal, as is distributing it to other people. “It is illegal to sell water,” Cape Town’s water and sanitation department spokesperson told the Sunday Times. “Even the department does not sell water...The only case in which water is sold legally is as bottled water.”

Some of the vendors reference this legal grey area in their posts. Mr. Water Deliver, which advertises 2,500 liters of water for 2,750 South African rand (about $232), markets itself on Gumtree as an ethical water delivery service, warning against other services that use municipality water from within Cape Town.

The quality of these private tankers and systems, sold from individual vendors, is also unregulated and uncertain—the last thing Cape Town needs is a bunch of shady water filters or contaminated tankers in which potable water could be rendered dangerous. And the cost could place a heavy burden on the residents—the United Nations says the average person needs 50 to 100 liters of water per day, and the average income in the city was around $1470 per month as of 2015.

Patrick Reed, a civil engineering professor at Cornell University, told me that this unregulated water market can be dangerous—pointing to Puerto Rico's recent crisis after the hurricane, when broken water systems meant the spread of disease. But in any city facing a drought, these kind of bandaid solutions are likely.

"I don't think its necessarily helpful that some uncontrolled illegal secondary market emerge, but obviously you have to mitigate the crisis," he said. "People are going to want water. They're going to find ways to access it, whether or not that exposes them to a risk."

Meanwhile, non-profit groups have also been attempting to distribute water in Cape Town, with funds raised from donors. Deon Smit, director at Water Shortage South Africa, told me in an email that the organization had received a truck with 28,000 liters on January 25, purchased with funds donated by the public and Uber South Africa.

"We have an estimate of 12,000 folks who will be unable to get to these [water pick up] points and these are the people we are trying to assist," he said.

Some Cape Town residents have also taken to Facebook to try and navigate their impending drought by forming groups like Water Shedding Western Cape. Sharing water regulation, memes, and ideas for water conservation, it’s clear Day Zero is weighing heavily on everyone’s mind.

"There a lot of cities that are confronting [water shortages]," Reed said. "But in terms of a city the size of Cape Town literally coming to a point that they to decide: What do you do when theres no water? This is a noteworthy moment."