Establishes legally binding extraction limits per aquifer basin, with tradeable permits allowing farmers and municipalities to buy and sell unused extraction rights.

Modeled after carbon markets: total basin extraction is capped at or below annual recharge rates, and permit prices rise as scarcity increases — creating direct economic incentives to adopt drip irrigation, drought-resistant crops, or recycled water. Aquifer basins in the Indus, Ganges, North China Plain, and Ogallala regions are facing 1-2 meter annual water table drops.

Without a hard extraction ceiling, voluntary conservation measures will always be outcompeted by short-term agricultural economics. Cap-and-trade creates a market signal that is self-reinforcing: the scarcer the water, the more valuable the permit, the stronger the incentive to conserve.