Water Economy: Pakistan
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Water Economy
May 20, 2007
EXCERPTS: Water for life
Drawing heavily on a set of companion reports by Pakistani water experts and policy analysts, this book urges dramatic changes in policy and approach to enable Pakistan to maintain and build new infrastructure, besides securing the water required for future generations
John Briscoe and Usman Qamar write about the challenges and achievements of water management in Pakistan
Pakistan is an arid country. The balance between population and available water already makes it one of the most water-stressed countries in the world. With rapid growth in population, it will soon enter a condition of absolute water scarcity.
In the cultivable plains, rainfall ranges from about 500mm a year along the Punjab border with India (which receives some rainfall from the summer monsoon) to only 100mm a year in the western parts of Pakistan. These low precipitation levels mean that rain-fed or barani agriculture is not possible on a large scale in Pakistan. Throughout history people have adapted to the low and poorly-distributed rainfall by either living along the banks of rivers, or by careful husbanding and management of local water resources. One of the greatest of human civilisations — the Indus Valley (Mohenjodaro and Harappa) Civilisation flourished along the banks of the Indus. But under natural conditions the population densities were necessarily low.
With British rule everything changed. As analysed in Deepak Lal’s history of economic growth in the subcontinent, the British understood that the marginal returns to water development were higher in regions of relatively low rainfall than in the higher rainfall areas, and thus emphasised hydraulic works which would “make the deserts bloom”. In many ways, the imperative was to “go West, young man”, including into the arid part of eastern Punjab.
In any social endeavor of such ambition, the result varies depending on the interaction of the natural and human terrain as described brilliantly in Imran Ali’s seminal book The Punjab Under Imperialism and in his background paper for this report. As the irrigation systems stretched further and further away from areas of reasonable rainfall, they dealt with quite different social realities on the ground and gave rise to different hydraulic civilisations. In UP and eastern Punjab, canal irrigation occurred primarily on already settled lands, and irrigation was a supplement to relatively well-watered, rain-fed cultivation. In western Punjab, the part that would be in Pakistan, the situation was quite different. Irrigation here was on to pastoral lands, only a small fraction of which were private proprietary holdings. These extensive barren tracts were appropriated as state property and categorised as Crown or State Waste Land. Not only were the rights of the pastoral tribes to the land not recognised but these tribes were also deemed to lack the agricultural traditions to make a success of cultivating new land. The British administration then embarked on a vast process of agricultural colonisation by essentially introducing colonists from other parts of the Punjab to these ‘canal colony’ lands.
A massive canal system was built with the principle being to maximise the use of run-of-the-river flows in the kharif season and to allow equal distribution to all irrigators by use of the warabandi, a time-based roster allocation system. Since that time agriculture in the region has largely been synonymous with irrigation, with rainfall playing only a supplementary role both for the spring (rabi) and autumn (kharif) harvests.
As population densities increased, especially in the areas adjacent to the rivers, so too did the vulnerability of people to the naturally meandering nature of heavily-silt-laden rivers, and to floods. Floods have, with considerable regularity, inflicted severe damages and caused many deaths. The nature of the flood protection and management challenge varies considerably across the country. In NWFP and Balochistan and parts of the Punjab, the so-called ‘hill torrents’ are usually highly beneficial, sustaining a large agricultural population. Occasionally, flash floods cause serious damage, as did the drought-ending floods in Balochistan in 2005. In the plains the problem is different. Punjab has problems both with inundation and land erosion but intelligent use of the natural, south-west slope of the land has reduced the impact of flooding.
In all river systems, and especially those with heavy silt loads, the greatest flooding problems are in the flat deltas. And so it is in Pakistan, where Sindh is basically a delta in which the Indus has meandered over millennia. As in all deltas, once silt is deposited in one place, the river shifts to a lower-lying area. In times of flood these can be very dramatic and long distance shifts. As larger populations inhabited the delta, however, this uncertainty was not acceptable and so, over the past one hundred and fifty years “the Indus river has now been put in a straitjacket, thereby fixing its location”.
The result of this river training, as with so many other silt-laden rivers around the world, has meant that when silt is deposited the river now does not shift course horizontally, but vertically, giving rise to a situation where the river is higher than the surrounding land, and the choice is between two unsatisfactory and expensive options — dredging, and continuing to raise the side embankments. The inevitable consequence is that “when a protection bund breaches in Sindh province, inundations are prolonged, and the floods not only damage summer crops but they also interfere with the sowing of subsequent winter crops. The potential for economic losses, and human sufferings for the poor inhabitants of relatively cheap flood-prone lands near the river, are the greatest. In addition to millions of acres of irrigated land that is subjected to flooding, the country’s major rail and roads are also sometimes affected by super flood events that keep the infrastructure out of service for long durations.”
Transforming an arid and capricious environment into one in which large numbers of people could live peaceful and prosperous lives is, everywhere, a great gamble and even, in the eyes of some, a Faustian bargain. The natural flow regimes of the rivers were dramatically altered. Rivers which had previously meandered over wide plains were now confined within narrow channels. The large quantities of sediments which were washed off of the young Himalayas in the spring floods now no longer nourished the delta but were diverted on to land (and later partially trapped behind high dams). Vast quantities of water were disgorged on to deserts, substantial parts of which were of oceanic origin and highly saline. And areas which were previously habitable only by nomads were now transformed into dense ‘canal colonies’ of immigrant farmers.
The area was, for better or worse, transformed into a hydraulic civilisation which brought great returns but which also posed, and poses, massive political, hydraulic, and economic challenges in maintaining an acceptable balance between the natural system and man.
The first challenge for the nation of Pakistan was a political challenge which arose because the hastily drawn lines of Partition severed the irrigated heartland of Punjab from the life-giving waters of the Ravi, Beas, and Sutlej rivers.
The second challenge was hydraulic in nature because there was now a mismatch between the location of Pakistan’s water (from the Indus, Jhelum, and Chenab, the so-called western rivers) with the areas that had previously been irrigated from the Ravi, Beas, and Sutlej (which were now ‘India’s rivers’).
The third challenge was neither political nor hydraulic, but ecological. It was this last reality which gave rise to the third major water challenge which Pakistan had to face at and after Independence. Hundreds of billions of cubic metres of water were now stored in the naturally-deep aquifers of Punjab alone. The groundwater table rose dramatically and in many areas water tables now reached the level of the land. And these waters were rich in salts which had been absorbed from the soil. After the water evaporated, the land was covered with a crispy layer of life-suppressing salt. In the early 1960s it appeared that Pakistan was doomed, ironically, to a watery, salty grave.
Excerpted with permission from
Pakistan’s Water Economy: Running Dry
By John Briscoe and
Usman Qamar
Oxford University Press,Plot # 38, Sector 15,
Korangi Industrial Area, Karachi
Tel: 111-693-673
ouppak@theoffice.net
www.oup.com.pk
ISBN 978-0-19-547476-3
126pp. Rs450
John Briscoe is The World Bank Director for Brazil
Usman Qamar is a water resources specialist who has been with The World Bank since 1981. Besides Pakistan, he also works on water projects outside South Asia, including Afghanistan, China and Iran
Water: Reservoirs’ storage capacity declining
By Ahmad Fraz Khan
LAHORE, March 12: Pakistan has lost 24 per cent of water storage capacity and its reservoirs can now hold only 11.38 million acre feet water against a capacity of 15.02maf, according to a survey of dams.
A survey of Tarbela dam has been an annual feature since 1981, whereas Mangla dam’s survey is conducted every three to five years because of little silt moving into the lake. According to the survey, Tarbela dam, which was completed three decades ago, had a gross capacity of 11.62maf and live (usable) capacity of 9.68maf, with 1.94maf water left in the lake (dead level) to check silt movement.
In 1979, Tarbela lost 3.3 per cent storage and its live storage capacity dropped to 9.36maf. In 1990, the loss came to 10.6 per cent, with storage dropping to 8.65maf. In 2000, the live storage dropped to 7.97maf a total loss of 17.7 per cent. In 2007, the loss has gone up to a whopping 24.07 per cent, with total capacity dropping to 7.35maf.
The loss at Tarbela was further aggravated by the raising of the dead level, which caused another loss of 0.511maf. The live storage thus further came down to 6.84maf from 7.35maf.
At Mangla, the live storage capacity has come down to 4.54maf against the original 5.34maf in 1967 when the dam was built. The loss has remained limited because of slow movement of silt in the lake and the dead level remaining the same over the past 40 years. The two dams had in the beginning a combined capacity of 15.02maf, which has now declined to 11.36maf. The cumulative loss at the dams has thus increased to 3.64maf or 24 per cent.
