Economists would generally argue that price is the right way (although with caveats, pure price allocation of drinking water in a drought might raise hackles) to do that rationing.

FORBES: Links 4 Nov: The Price Of Gas Is Just The Price Of Gas, Anti-Gouging Laws Be D'mned

Kathmandu's residents have learned to live with much more deprivation than fuel rationing--four- to eight-hour power outages daily and an acute shortage of drinking water.

FORBES: Himalayan Vistas