Waterlogging
blues of SW Punjab
By Sushil
Kumar Mittal
AROUND the turn of the century,
canals were constructed to divert water from various
rivers in the Indus basin. This changed the agricultural
complex and made the state not only surplus in foodgrains
but also the largest contributor to the Central pool
(60-70 per cent wheat and 40-50 per cent rice). The
development of irrigation had, however, mixed blessings.
As in other doabs of the Indus, waterlogging followed
surface irrigation in cis-Sutlej doab too.
By 1965, the central
part (fresh groundwater area) of Punjab was in the grip
of waterlogging. This was suitably tackled by the state
government by way of constructing drains and large scale
groundwater abstraction (through private tubewells) to
meet the demand of paddy crop which was introduced as a
second major crop in the state. However, the groundwater
continued to build up in south western (SW) Punjab where
native groundwater is of poor quality.
Ever increasing rise in
water table in SW Punjab brought about 63,000 hectares of
land under waterlogging by 1978. The problem attained
serious proportions during the period 1980-88 when about
2,00,000 hectares was severally affected by waterlogging.
The crop yield of the cotton slumped down to 40 per cent.
Though only temporarily, the situation was brought under
some control due to poor rainfall cycle and the efforts
of the state government by way of providing improved
surface drainage, vertical drainage (private shallow
tubewells). Even during the lean period, there was no
significant change in the sum total of waterlogged areas
(01.5 m) and critical areas (1.5-3 m) indicating only the
fringe benefits of the various schemes.
During the year 1997-98,
the menace of waterlogging again surfaced over an area of
about 1,70,000 hectares which was mostly in the newly
carved district of Muktsar. The magnitude of the problem
was only marginally less as compared to the eighties. The
estimated loss of cotton was about Rs 1200-1400 crore. As
in the past, the state government again pressed its
machinery into action.
Water & Power
Consultancy Services India Ltd. (WAPCOS) during 1989
predicted that by the year 2000 and 2010, there will be
about 5,21,000 and 7,02,000 hectares of area under
critical waterlogging. Apart from traditionally
waterlogged areas of the districts of Ferozepore,
Faridkot, Muktsar and Mansa, the district of Bhatinda
will also fall prey to the menace. Immediate preventive
measures for the critical areas is the need of the hour.
Past experience has shown that vertical drainage has
proved most to be the effective tool in controlling the
menace of waterlogging.
Prior to the
introduction of surface water irrigation (1895) in SW
Punjab, the depth of the water table varied from 20 to 50
metres. Prior to 1970, the water level observations are
rather sparse. In general, there has been continuous rise
at the rate of about 0.5 m/yr (average 1895-1963) in SW
Punjab against periodical rise/fall in NE part of Sirhind
canal system in a span of 20 years.
With Green Revolution
(1965-66), there was steady increase in the cropping
intensity (1960-61 126 per cent; 95-96 185
per cent). Paddy was introduced as a second major crop in
the state. The groundwater resources in the central zone
of the state became over-exploited. There has been steady
decline in the water table varying from 0.05 to 0.5 m
depending upon hydrogeological conditions and the
rainfall during that period indicating over-exploitation
of the resource.
From 1982 onwards, the
problem of waterlogging has attained serious proportions
though there have been variations in the areal extent
with the shifting of water table contours from NE to SW.
During the period from 1980-82, many parts of the then
district of Faridkot (including Mukatsar) were in the
grip of waterlogging threatening the buildings and
agricultural production in the state. There was shift
from cotton to paddy in the waterlogged areas. Amongst
other measures, vertical drainage through farmers private
tubewells proved to be effective. Thereafter, from 1992
to 1995, the situation was under control largely being a
dry cycle and increase in number of shallow tubewells in
district Faridkot from 33,000 (1978-79) to over 1,00,000
(1996-97). It is noteworthy to mention that even during
the lean period, there was no significant change in the
sum total of the actually waterlogged and the potential
area for waterlogging (critical area). It is a sensitive
situation. During the 1997 episode, because of the heavy
monsoon rainfall, it was only the potential area for
waterlogging that was added to the kitty of waterlogged
area causing havoc. The situation since 1982 has been
critical and reduction in the area has been only a
border-line case of waterlogging. Monsoon is the key
factor in spread of waterlogging conditions.
The area is the cotton
belt of the state and produces about 22 per cent of the
cotton in the country. Cotton is the main Kharif crop and
wheat is the Rabi crop. Waterlogging conditions have not
only severally affected the crop yield of cotton but also
forced the farmers to shift to paddy (25 per cent in
district Muktsar alone during 1998-99). During 1983-84,
the average yield of the cotton drastically came down to
40 per cent (compared to 72-73) in district Ferozepore
and 47 per cent in district Faridkot (including district
Mukatsar). It touched as all time low during 1997-98 to
the tune of 32 per cent, 41 per cent and 57 per cent in
district Faridkot, Mukatsar and Ferozepore, respectively.
The native groundwater
in SW Punjab is saline. However, as a result of
continuous seepage from surface irrigation system and
subsequent rise in water table, there was marked
improvement in the quality of groundwater at shallow
depths. As a result, the fresh water floats over the
saline water. However, there are frequent variations in
the chemical quality depending upon the thickness and
extent of impermeable (clay) layers. To avoid up coning
of the saline water, 3/4 filter points joined together to
a single pumping unit should be preferred.
Rainfall, seepage from
surface irrigation system and surface bodies are mainly
responsible for waterlogging. From 1948-97, wet rainfall
cycle has been experienced. Similarly, widespread network
of Sirhind canal system, Sirhind; Rajasthan and
Ferozepore feeders, Bikaner and eastern canals are
significantly contributing to the waterlogging. On an
average, 33 per cent of the water let in at head goes
into the sub soil. The duty allowance of water has also
steadily increased with the construction of Bhakra canal
system and Harike barrage. The water allowance in the
command area of eastern canal is the highest in the state
(5.5 cs/1000 acre) at the outlet head. In other parts, it
is about 3.05 cs/1000 acre.
Remedial measures to be
adopted must be area specific depending upon
topographical, hydrological set up.
Tubewell drainage
(vertical drainage) has been by far the most effective
tool in meeting the challenge. In order to exploit the
fresh water at shallow depth, multiple filter points
joined together are most successful in lowering the water
table. Groundwater should be preferably used in rotation
with canal water. Additional requirement of water for the
paddy crop should be met with from groundwater itself.
According to a study, the shift from cotton to paddy
implies 52 per cent reduction in the area by the same
quantity of water. As an incentive, the Punjab government
is already in the process of releasing 2000 energy
connections for tubewells in the waterlogged area.
Effectiveness of the
direct irrigation tubewells in lowering the water table
have its own limitations vis. availability of the canal
water for conjunctive use and up coning of the saline
water. Alternatively, a battery of tubewells along major
canals/distributaries in the area and groundwater mixed
in a proper ratio. This will avoid any after- effects of
the use of mixed water like salinisation. The Punjab
government have already initiated a programme of
installing 500 tubewells along right bank of Sirhind
feeder. Conceptually, it is a serious effort but the
distance of the tubewells from the canal (about 250 feet)
is in itself a question mark on the effectiveness of the
proposal. By way of reference, it may be added that
similar schemes were implemented in Rechna doab and
tubewells were installed at a distance of 600 feet from
the canal.
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