The Indus civilization stood around 5,000 years ago in what now is northwest India and Pakistan. The civilization was known for cotton and date farming and some of its cities even had plumbing and a working sewer system.

Scientists were confused about how the civilization thrived in the desert without a nearby river source. Though there was a glacier-fed river there once, historians once believed that the civilization dried up as soon as the river did. But recent research revealed that the river dried up 3,000 years before the collapse of the Indus civilization. Meanwhile, the civilization relied on monsoon flooding to trap groundwater in the clay in order to extract it and feed their crops.