Water Markets
This article in Forbes acknowledges that scarcity of water is leading to water markets, which will lead to more rational use of water.
...scarcity has already spawned
informal water markets in parts of Texas and Mexico. The prospect of
shortages has attracted a growing number of venture capital firms and
investment funds to place big bets on technologies aimed at
replenishing water supplies.
...
"Sooner or later, the way in
which the world adapts to shortages is with price," says Levinson. "So
my expectation is that water is going to become increasingly costly as
an input for all kinds of purposes, and when that happens you'll see a
lot more interest in conserving water."