Water is the main source for development for all human beings, cattle, and industries from the history of global system we learn that, in ancient days, perennial rivers became the major source of water, and the people, who were far away from the river sources, practiced the utilization of ground water and stored rain water for their sustenance. In India ground watert utilization has been practiced for many centuries, in the form of open wells owned by private individuals or communities, for both domestic and irrigation purpose
Well irrigation has been in practice for several centuries. To meet shortage of tank/canal waters, cultivators made conjunctive use of ground water through wells. But there was no specific planning behind this, because each source was developed without due consideration of the other.
Effecient planning and management of water sources, for irrigation/industrial and other uses,is an important aspect for the development of any system. Recognition of the fact that ground water and surface water are not seperate entities but are two forms of the same total water sources, leads to the recognition of the importance of conjunctive water use in the management of ground water - surface water system. But due to the land intended for recharging, the surface water is wasted as run-off in to the sea whereas ground water table depletes to an alarming level. This in turn results in the reduction in well yield, during up of shallow wells, deterioration of water quality , sea water in trusion into the coastal aquifers, increased energy required to lift water from greater depth and its consequent high cost, agricultural fertile lands have become barren in coastal area like Minjur (Thiruvallur District), Kuttam, Athisayapuram in Thuthukudi District and Nagapattinam and Thiruvarur in Thiruvarur District of Tamil Nadu. Further about 89 blocks have been identified as overexploited and dark bloks where the balance available ground water potential shows a extraction over the various periods is shown in the chart. In order to check this disturbing trend, the rain water is to be conserved.
Rain Water Harvesting Methods:
- Rain water harvesting through percolation pit method.
- Rain water harvesting through broken brick method.
- Rain water harvesting through well cum canal cum percolation pit method.
- Rain water harvesting through open wells.
- Rain water harvesting through defunct bore well method.
- Rain water harvesting through ponds.
- Rain water harvesting through ditch and furrow storage.
- Rain water harvesting through recharge wells.
- Rain water harvesting through service well cum recharge well method.