THE Indus Basin is currently the second-most overstressed aquifer and is among 21 of the world’s 37 largest aquifers which have passed their sustainability tipping points, meaning more water has been removed than replaced.

Two new studies published on June 16 by Nasa scientists say that human activity is leading to the rapid draining of about one-third of the planet’s largest underground water reserves and it is unclear how much water remains in them. Already,2bn people worldwide rely on groundwater for daily use. The researchers used data from special NASA satellites to measure groundwater losses. They had long suspected that people in densely populated regions such as northwest India, Pakistan and North Africa, were taxing the underground water supply.

Groundwater in Pakistan, being in Indus Basin aquifer, is running out on fast pace. The World Bank and the Asian Development Bank have already categorised it as a water-stressed country, likely to face an acute water shortage over the next five years due to the lack of surface water availability for irrigation, industry and human consumption. If this trend continues, the ground water table will come under severe pressure. The world’s most over-stressed source is Arabian Aquifer System, providing water for more than 60m people.

The WB and the ADB have already categorised Pakistan as a water-stressed country, likely to face an acute water shortage in the next five years

According to Punjab irrigation department, the water table in the province is going down by three feet per year. In Lahore, for instance, water could be extracted at 20 to 40 feet 20 years ago but now drilling has to be done up to 800 feet to reach water. In 2000-01 tubewells installed in the country were 659,278 and in 2012-13 their number had gone up to 1175,073.

Another cause of the alarming situation is the lack of planning to build more water storages. Pakistan has just three dams and scores of small barrages as compared to China having 22,000 and India 4,200 small and big dams. The per capita storage capacity in the United States stands at 6,150 cubic meters, in Australia at 5,000 cubic meters and in Pakistan it is just 132 cubic meters that shows how vulnerable Pakistanis are in terms of access to water.

Intensive farming is also putting pressure on groundwater table. In the past, farmers used to cultivate one crop in a year. Now they produce three or four crops in a year which requires excessive water. In Punjab, more than 50pc of irrigation water requirement is met from groundwater.

There are rules and laws for regulating the use of, and access to, surface water but the groundwater which constitutes 55pc, compared to surface water’s contribution of 45pc, of total water availability is under no legal discipline. There are no laws to govern its use nor had any government thought of creating a legal structure to regulate a commodity whose overuse can lead to a major disaster for the people and the economy. There is a dire need to switch to greater use of surface water from groundwater whose use should be resorted to in emergencies. But that requires a greater planning to make it possible. The Punjab government had been thinking in these terms in the recent past but has yet to take practical steps.

Balochistan is the most water-stressed province in the country where the indiscriminate use of groundwater resources in general and in the Quetta valley in particular has led in recent years to excessive depletion of the aquifer. This led to serious socioeconomic impacts and resulted in migration of rural population to urban areas. With funding previously provided by the United Nations Development Programme and the Global Environmental Facility, researchers at one of the US universities had developed methodologies for groundwater assessment in Balochistan.

Since Balochistan is facing a drought-like situation in various districts, Japan has also been providing assistance to the province for searching underground water resources. In May this year, Japan provided spare parts of drilling rigs to the provincial government to accelerate work on finding locations of underground water resources. The spare parts would be used by the irrigation department to repair drilling rigs lying idle for years.

The scientists at Nasa used Grace satellites to take precise measurements of the world’s groundwater aquifers. The satellites detected subtle changes in the Earth’s gravitational pull, noting where the heavier weight of water exerted a greater pull on the orbiting spacecraft. Slight changes in aquifer water levels were charted over a decade, from 2003 to 2013.

But the satellites could not measure the total capacity of the aquifers. The size of these water supplies remains something of a mystery. Still, the satellite data indicated that some aquifers may be much smaller than previously believed. Aquifers can take thousands of years to fill up and only slowly recharge with water from snow-melt and rains. Now, as drilling for water has taken off across the globe, the hidden water reservoirs are under stress.

Published in Dawn, Economic & Business, July 6th, 2015

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