Water as currency

He who controls the water, controls QUD.

In QUD, fresh water is the primary currency used in trading due to it's incredible scarcity. Fresh water has a significant weight associated with it. Each 10 drams (10ml) is equivalent to 1 dollar in Savage Worlds. So conversion is relatively easy.

Humans need to drink at least 500 drams of water to survive everyday, meaning you lose ~50$ a day to live.