*10.2.7 Induced recharge*

It is an indirect method of artificial recharge involving pumping from aquifer hydraulically connected with surface water, to induce recharge to the ground water reservoir. When the cone of depression intercepts river recharge boundary a hydraulic connection gets established with surface source which starts providing part of the pumpage yield. In such methods there is actually no artificial build up of ground water storage but only passage of surface water to the pump through an aquifer. In this sense, it is more a pumpage augmentation rather than artificial recharge measure.

**Figure 11.** *Dug well.*

Usually the ground water recharge is possible in a proper way as the abandoned channels in the hard rock regions act as a good site for the induced process of recharging. For this process, the check weir at stream channel helps in infiltration of water from surface reservoir to the abandoned channels which are then directed towards the aquifers.

During the unfavorable hydro geological conditions, induced recharge process has a greater advantage and also it helps in improving the quality of surface water which is generally improved due to its path through the aquifer material before it is discharged from the surface. Also, for the purpose of obtaining very high water supplies from the river bed deposits or waterlogged areas, collector wells are constructed. In India, these kinds of collector wells are constructed in the river bed such as Yamuna bed at Delhi and also in other places in Gujarat, Tamil Nadu, and Orissa as these wells are economical due to large discharges and lower lift even though initial capital cost is higher as compared to tube well. If the phreatic aquifer is situated near the river of limited thickness, then instead of horizontal wells, the vertical wells could be adopted which is rather effective than the other [17].
