| Possibility to Create Small
Artificial Aquifers in Northern Thana District
The author observed that a considerable number of soil
conservation works have been
implemented in hilly areas of Northern Thana District in
the past years. The main scope of
the large number of nala dams constructed serve mainly to
trap silt and coarse material
transported by run-off water by the numerous water
courses incising the area. Most of
these structures could be very useful if constructed with
the double scope to act as silt trap
and as artificial aquifers. Water stored in these
deposits could be tapped by open dug
wells, infiltration galleries, by a pipe inserted at the
base of the masonry dams, or by other
means. The draining pipe should be slotted and extend
several meters behind the dam, a
sand pack filter should be installed around the pipe to
prevent clogging of the slots. The
flowing pipe could be connected by a small water tank to
be constructed adjacent to the
dam. The pipe could also be equipped by a tap, to be
opened and closed according to
water demand. Water could also be piped by gravity to a
lower lying place, if required.
The construction of silt dams in hilly areas should take
place in consecutive years until the
planned dam height is reached. The stored water would
drain slowly, alleviating in this
way the water shortage during the driest months. The
masonry dams should not be leaking
and the sand reservoir should be sufficiently large to
satisfy people’s needs.
Rice or other crops can be cultivated on the topsoil
covering the sand reservoirs, if no
fertilisers or chemicals are used.
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