THE sustainability of groundwater resources in Pakistan faces a number of challenges. Unconfined aquifers are subject to massive overexploitation and contamination, mainly because of climate change and a growing population.

As a result, the dependence on groundwater is increasing day by day.

It has been reported that there will be an unprecedented 20 per cent decrease in the surface water flows as compared to the usual scenarios in winters, and this will increase pressure on groundwater reserves.

It is estimated that the groundwater contribution to irrigation water supplies in Pakistan has already increased from just 8pc in 1960 to more than 50pc in 2010. Presently, the country meetsmore than half of its overall irrigation water requirements and 70pc of its drinking water consumption from groundwater abstractions.

This makes Pakistan the fourth-largest groundwater withdrawing country, with an estimated 65 cubic kilometres of groundwater abstraction per year according to estimates in 2010.

As per 2010 statistics, Pakistan accounts for about 6.6pc of the global groundwater withdrawals and irrigates about 4.6pc of the global groundwater-fed cropland.

Due to excessive pumping, Pakistan`s groundwater abstraction rates have exceeded the annual recharge rate of 55 cubic kilometres per year.

Consequently, groundwater tables are lowering rapidly in different parts of the country.

Some hydrologists think that there could be a 10-20 metres decline in the groundwater tables in the upper and the lower regions of the Rachna Doab in north-east Pakistan by 2025.

However, Pakistan continues to overexploitgroundwater resources to support its low waterproductive agriculture and to grow and export water-intensive crops like rice without realising its water footprint.

Pakistan`s rice water productivity at 0.45kg per cubic metre is 55pc lower than the average water productivity of 1kg per cubic metre for rice in Asian countries.

A recent study found that about 11pc of the global groundwater depletion is owing to international food trade. Pakistan exports about 29pc of the global non-renewable groundwater embedded in agricultural trade, and almost 82pc of this non-renewable groundwater export is embedded in only rice exports.

Besides massive groundwater depletion, Pakistan is amongst the top five countrieswhich account for about 86pc of the global wastewater-fed cropland, including China, Mexico, India and Iran.

Of them, China and India treat 71pc and 22pc of their urban wastewater compared to only 1.2pc in Pakistan.

The untreated urban wastewater is used to irrigate about 2.9 million hectares of land in different parts of the country. On the one hand, the untreated urban waste water is openly being disposed of into freshwater bodies but, on the other, the Punjab Food Authority discarded some 700 acres of vegetables which were being irrigated through untreated wastewater.

The authority should deal with the root cause first. Some canals such as Lower Bari Doab and Balloki-Sulemanki Link Canal now carry untreated wastewater these days which irrigates thousands of acres land downstream. Such instream wastewater flows and irrigation applications, if continue for long, will have serious repercussionson the quality of groundwater underneath and quality of grown food as well.

A recent study has already warned that the health of 50m to 60m Pakistanis who use groundwater are at risk owing to high arsenic contamination.

According to a 2005 World Bank report, poorquality drinking water and inappropriate sanitation cause of number of diseases such as diarrhoea, typhoid, intestinal worms and hepatitis which made Pakistan pay an indirect cost of around Rs114 billion.

This indirect spending is far more than the total funds of Rs38bn allocated for the overall water sector development in the budget 2017-18. The intangible environmental costs have yet to be unaccounted for.

Only because of salinity more than six million hectares of land was reported to be affected in 2004. Of this, 1.4m hectares of land was so severely affected that it was not cultivable. The economic losses due to salinity were estimated to be Rs55bn, or 0.6pc of GDP during that year.

Despite the rapid groundwater depletion and a number of negative economic and environmental consequences of groundwater overdraft, groundwater is still one of the most neglected resources in the country.

Currently, there is no mechanism of groundwater governance either in terms of protecting it from over-drafting or from polluting it. Moreover, there is a lack of comprehensive assessments on groundwater.

Some of the most alarming factors include a lack of public knowledge and awareness and the orthodox narrative about groundwater resource situation and its management.

At least one thing requires immediate action: to limit groundwater extractions and put a stop to polluting groundwater aquifers with wastewater and untreated reuse.

However, the biggest challenge is how such regulations can be enforced in the absence of a national water policy. • The writer is an assistant professor at the Institute of Agricultural Extension and Rural Development, University of Agriculture, Faisalabad