Ground water is the water contained beneath aquifer rocks or earth pores or fractures. Ground water is actually contained at a depth we get usable water with low dissolved solids; surely not at upper layer of soil. It’s confined in the impermeable rocks in huge volumes. Ground water is approx. 20% of total world’s fresh water. Groundwater is huge storage of water much more than total surface water available on the earth. Ground water is highly useful and abundant resource for the survival.
Over use or over extraction of ground water has been most worrying at present. Depletion of ground water levels due to rampant drawing of water is a major concern for the sustainability of habitat. Levels of the water table have gone beyond the reach of existing wells. On account of which wells must be drilled even deeper to reach the groundwater; in some places the water table has dropped hundreds of feet because of extensive well pumping. Ground water levels have dropped more than 10 meters in couple of years and the rate of depletion is accelerating day by day.
Groundwater is also ecologically important. It sustains rivers, large water bodies, wetlands, ponds and lakes in addition to subterranean ecosystems within alluvial aquifer zones. Groundwater feeds soil moisture through percolation, and many terrestrial vegetation communities depend directly on either groundwater or the percolated soil moisture above the aquifer for at least part of each year. Below mentioned facts enlighten us more about ground water.
Ground water Recharge is less expensive than surface water.
Efficient compared to over ground storage structures
Less vulnerable to pollution than surface water
Improves ground water quality by dilution
No Conveyance or evaporation loss
Increases productivity of Aquifer
Reduces Soil erosion
Rain water harvesting is the most important task that enables us to replenish our ground water levels with pure, fresh and soft water. Rain water; available in huge volume; can be captured, filtered and diverted to the aquifers through specially made recharge wells or dug wells. Direct diversion through such wells results in immediate rise of water tables than the natural percolation.