“The major problem in the Cape Town case was having one [type of] source of water that as a result of climate change was at much greater risk than it had been prior,” says Barton Thompson, a senior fellow at the Woods Institute for the Environment at Stanford University. He says all of Cape Town’s reservoirs were dangerously low because of a lack of rain. Even though Cape Town had “spent years conserving water,” the city’s continued growth left the system unable to adjust.