Mohammad Hussain Khan
LAST year`s flash floods wreaked havoc on livestock and
agriculture in Sindh but had some positive impact on soil
and ground aquifers. Soil fertility improved greatly while
the fast depleting ground aquifers — an important source of
irrigation and fresh drinking water — were replenished.
Groundwater level had dropped 30-35 ft in last one decade
because of excessive use of tube-wells for irrigation of
lands. This caused immense hardship to the rural population
which, to a great extent, depended on groundwater aquifers
for drinking purpose in absence of any water supply scheme
or purification plants.
Drainage and Reclamation Institute of Pakistan (DRIP),
Tandojam, which works under the ministry of science and
technology, regularly monitors around 100 tube-wells of land
owners in districts of Nawabshah, Naushahro Feroze, Matiari
and Khairpur which are on the left bank. The institute
examines different aspects of groundwater. In recent
monitoring following last year floods, it found that fresh
groundwater table had improved up to 12-13ft from previous
According to institute in-charge Mohammad Khan Mari in some
areas the table has improved up to 5ft. An old study that is
often quoted on groundwater quality by experts, 84-85 per
cent of it is brackish. Barring few pockets, groundwater is
brackish in most part of the right bank. Freshwater aquifers
exist on left bank of the Indus River within a radius of
30-35km, he says.
“We need to utilise this reserve efficiently when there is
water shortage in river and canal systems. We can have a
good use of it for around four years if we manage it
properly”, he emphasises.
An efficient use of this water reserves is being recommended
by agriculturists to make it sustainable for a longer
period. They say floods did improve land`s fertility and
recharged aquifer, important resource of water, and it must
Sindh Abagdar Board (SAB) president Abdul Majeed Nizamani
and general secretary Mehmood Nawaz Shah stress the need for
conducting a baseline study to get exact data of groundwater
aquifers and use of systems like drip and sprinkler. Such
study should show for how long this reserve will be
sustainable. They point out that the rise in water table as
high as 5ft could be harmful for plans because it affects
their root, and systems like drip and sprinkler can be
helpful in water conservation.
According to Mohammad Ahsan Siddiqui, water technologist,
geophysical formation of soil in Sindh indicates presence of
limestone which blocks penetration of freshwater and hence
brackish quality of groundwater. Limestone doesn`t allow
rain or floodwater to cross it.
He referred to a study conducted in Sindh during the first
tenure of Nawaz Sharif government through Japanese experts.
“I assisted experts in that study which established the fact
that Sindh`s 80-90 per cent soil has limestone whereas in
Punjab land`s quality is better than Sindh`s,” he says.
The quality of subsoil water on the right bank of Indus
River is brackish whereas freshwater aquifer is available on
the left bank. Yar Mohammad Khuhawar of Sindh University`s
High Technology Resource Centre Laboratory says that
underground water basically flows towards left side of the
Indus and freshwater reserves are found in that pocket.
Environmentalist Naseer Memon says: If you keep on using
groundwater excessively in absence of proper recharge
mechanism it will badly affect it. If sub-soil water is
available by 10ft it is a blessing for farmers. It will
serve as important source of drinking water but beyond 10ft
it will harm quality of crop barring rice”, he says.
Heavy rainfall and floods serve as main sources for
recharging of aquifers but over the last one decade the
province has gone through a long dry spell. It forced
farmers to opt for massive tube-well operation which dealt a
telling below groundwater. Rainfall recharges groundwater
aquifers but experts believe that such contribution is not
more than two per cent as compared to floods. They stress
the need for an efficient management of groundwater aquifer.
Courtesy: The DAWN