Recharging aquifers

The availability of fresh water in a region can be augmented by cutting loss through evaporation, by means of underground storage instead of storage in surface-water reservoirs. The costs, while high, seem reasonable compared to alternative schemes.

Preserving natural storage can avoid the costly construction - and maintenance - of dams and reservoirs, save costs incurred by flood damage, and offer a reliable source of water supply for drinking and agricultural purposes.

Most groundwater resources are being replenished at a rate of between 0.1% and 0.5%.

At present, more than 20 countries have projects to recharge ground water artificially, but in only a few of them has the practice been implemented on a large scale.

Underground water storage may hold special potential for developing countries subject to the destructive flooding and perennial dry spells of monsoon climates. Many aquifers are recharged unintentionally by seepage from irrigation canals. In such cases, managing ground water in conjunction with surface irrigation water, without developing additional surface-water sources, might help to prevent waterlogging and salinization and make possible the expansion of the irrigation area.