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Today's Paper | November 18, 2024

Updated 30 Sep, 2024 09:33am

Agriculture: Water scarcity — an irrigation crisis

Water has become the most crucial limiting factor for Pakistan’s agricultural growth. Despite the availability of millions of acres of barren land, particularly in Balochistan and Punjab, the country’s cultivated area could not be expanded in the past due to the scarcity of surface and quality groundwater.

In Pakistan, water scarcity is an increasingly important issue, resulting from a complex interplay of inadequate water storage capacity, significant conveyance losses across water channels, and poor water-use efficiency — crop produced (in kilogram or in dollars) per unit of irrigation water used — at farm level, primarily due to outdated irrigation practices like flood irrigation.

If we look at the supply side, the country’s two largest water resources — glaciers and underground water — are depleting at an alarming rate. The ongoing rapid melting of Himalayan glaciers due to rising temperatures may cause a greater incidence of floods in the short term. However, in the long run, this will result in severe water shortages once the glaciers have significantly shrunk.

Pakistan’s water shortage capacity is critically low to get the benefits of increased water flow due to climate change. Over time, the country’s water storage capacity has gradually declined from 16.26 million acre-feet (MAF) to 13.68 MAF. As a result, the country has only a 30-day water carryover capacity as of 2021, which is in stark contrast to India’s 170 days and Egypt’s 700 days.

With low storage capacity and a stressed groundwater aquifer, Pakistan needs to adopt water-efficient irrigation practices

Pakistan, despite having just three per cent of the world’s population and contributing a mere 0.36pc to global GDP, accounts for an astounding 9pc of the world’s total groundwater withdrawals, making it the third-largest user after India and the United States. The unchecked and ever-growing reliance on groundwater — 73pc of Pakistan’s area is directly or indirectly dependent upon groundwater — has pushed Pakistan into the category of countries where groundwater extraction exceeds the natural replenishment of aquifers.

Furthermore, Pakistan is getting warmer due to human-induced climate change, with the 2010s and 2000s being the hottest and second-hottest decades, respectively. In addition to the rise in mean temperature, the frequency, duration, and intensity of heat waves are also increasing.

Rising temperatures have increased the evaporation rate in water channels and enhanced the evapotranspiration — water lost from evaporation and plant transpiration — in agriculture fields.

Such water loss is particularly high in the water-guzzling rice crop, where farmers often keep fields flooded for several months. Rice crop acreage has increased 31pc over the last 10 years, driven by several factors, including better marketability of rice due to its higher export potential, strong local demand, and relatively higher returns. Additionally, the crop area of two other water-intensive sugarcane and maize has also considerably expanded in recent years.

Pakistan accounts for 9pc of the world’s total groundwater withdrawals, making it the third-largest user after India and the United States

Due to the population explosion, food security is becoming an intense challenge for Pakistan, which is being responded to through input-intensive farming, the expansion of agricultural land, and increased cropping intensity. However, these strategies require additional water, placing intense pressure on our irrigation system to produce more with less water.

In short, water demand in Pakistan’s agriculture sector is rising, while water supplies are becoming increasingly uncertain. Meanwhile, water losses and irrigation inefficiencies remain exceptionally high.

Pakistan has made significant strides in reducing water conveyance losses through the lining of canals, distributaries, and watercourses, funded by soft loans from the World Bank and other international development partners. These megaprojects, initiated during the 1970s, are still ongoing under the Annual Development Programmes of provincial irrigation and agriculture departments.

However, water-use efficiency at the farm level is a crucial area where Pakistan lags significantly behind. As reported by the Food and Agriculture Organisation of the United Nations, Pakistan’s irrigated agriculture water use efficiency — Sustainable Development Goal 6.4.1 — is abysmally low, averaging just $0.40 per cubic meter in 2021 compared to countries like Bangladesh, India, and China where it stands at $0.98, $0.49, and $2.51 per cubic meter, respectively.

Beyond that, the adverse effects of electricity tariffs for agricultural tube wells on farmers are further compounded due to low water-use efficiency. As a result, irrigation has turned out to be the largest cost factor in the overall cost structure of crops, significantly undermining the economic viability of Pakistan’s crops.

An increasing number of farmers are shifting to solar-powered tube wells to reduce irrigation costs without compromising water consumption. However, these systems have yet to prove as reliable alternatives as grid-powered ones due to the limited availability of sunlight, which is further hindered by weather conditions like cloud cover, fog, and smog.

In conclusion, Pakistan’s impending water crisis, coupled with rising water prices, makes it imperative to enhance water-use efficiency through the adoption of water-efficient irrigation practices and the widespread use of high-efficiency irrigation systems, such as drip, rain guns, sprinklers, and pivot. The urgency of these measures has never been greater, as they are essential today for maintaining, if not improving, the cost competitiveness of Pakistan’s agriculture sector.

Chaudhary Mohammad Ashraff is a former Director General (On-Farm Water Management) of the Punjab Agriculture Department, and Khalid Wattoo is a farmer and a development professional.

Published in Dawn, The Business and Finance Weekly, September 30th, 2024

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