| Groundwater Recharge
Percolation Tanks
The recharge of shallow aquifers is a common
practice in rural India. Percolation tanks
have been successfully constructed in large numbers (more
than 8,000) all over
Maharashtra, therefore there is no need to describe them.
Percolation tanks, as well as
underground check dams, continue contour trenching, and
other water retention
structures, induce rainwater to infiltrate and recharge
seasonal and low yielding drilled and
dug wells. They are common techniques used in watershed
development.
Blasting and Hydrofracturing
Increase of hand-dug well yield can be obtained
by increasing the effective well diameter
without affecting the well size; this can be obtained by
drilling a number of shallow
boreholes around a large diameter hand-dug well and
blasting inside each hole. The
blasting helps to interconnect fractures, thus creating
additional storage and recharge to
the well. This technique has been experimented by the
Groundwater Survey and
Development Agency (GSDA) and described by B.G.
Dhokarikar, ref. n.2..
Blasting technique is also used in low-yielding boreholes
in an attempt to widen the water-
bearing fracture zones and interconnect them with the
water-bearing fissures of the
surrounding areas. In recent years, the hydrofracturing
technique has been successfully
experimented by the Government in low-yielding boreholes.
This technique widens
microfine fractures or joints and interconnects them with
fracture zones adjacent to the
low-yielding borehole.
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