A ratio of actual water withdrawals, or water use, to renewable supply that exceeds 100 percent is a key indicator of unsustainable water use, for non-renewable water in deep aquifers can only be used once .22 In 1990, nine countries used water in amounts more than 100 percent of their renewable supplies, with Libya's water withdrawals equal to nearly four times its renewable water resources.
(supply; exceeds; 100 percent) (nine countries; used; water; in amounts)
supply nine countries
exceeds used
100 percent
water in amounts