Courting disaster

Dawn | August 18, 2017

SIXTEEN million people in Pakistan lack access to safe water. Scarcity of clean water and poor sanitation claim 19,000 children under five years of age in Pakistan annually, according to WaterAid. Per FAO/World Bank data, Pakistan’s internal renewable freshwater per capita is less than that in Syria, whose civil war has in part been attributed to water scarcity.

The Pakistan Council for Research in Water Resources forecasts worsening scarcity. The way in which new hydroelectric plants on the Chenab and upstream Jhelum are operated by India could further exacerbate shortages.

Besides taking the legal action that the government is against India, Pakistan needs to reduce water wastage to prevent worsening scarcity; it must also widen access to potable water.

Agriculture accounts for 97 per cent of Pakistan’s water consumption, making it the natural place to look first for waste reduction.

Waste reduction and technology could help limit water scarcity.

To start, the government can minimise distribution losses along irrigation canals. Samplings by researchers at the University of Agriculture, Faisalabad, suggest losses as high as two-thirds among unlined watercourses; lining seems to reduce losses by a fifth. Maintenance can also reduce residual losses. Despite being categorised as water scarce in 2005, rice-growers over-irrigate their fields, limiting productivity. Pakistan exports almost a quarter of its extracted ground­water through rice exports, which account for 7pc of the country’s exports monetarily.

Unless the government starts taking steps to curb the over-tapping of groundwater for water-intensive crops such as rice, sugarcane and wheat, farmers will eventually be forced by a low water table and increased costs of extraction to find more sustainable ways of farming.

Given the right balance, strands of rice would not draw so heavily from groundwater. Our ancestors along the Indus had reason to farm it 4,500 years ago: it is resistant to monsoon floods. Poly-cropped in the summer alongside drought-resistant millet as well as protein-filled beans, rice strengthened the flood resistance of millet, now largely perceived as birdseed, but a cereal worth the government’s time to market for human consumption once again. As a cover-crop, it increases rainfall infiltration and retention.

Waste reduction alone, however, will not increase access to potable water to those currently without. This is where technological innovation should play a role.

Farmers in the dry hills above Lima, Peru, harvest their morning fog using nets. Nets stretched vertically between poles catch 200 to 400 litres of non-precipitating droplets per day, which are then carried by gutters to storage containers. As in the case of Lima, Karachi, which is home to perhaps a tenth of the total population of the country, sits on the coast and is humid year-round, but the bulk of precipitation is confined to just three months. The water is not potable, but given the low cost of erecting nets in open spaces and on rooftops, it is worth seeing whether yields would be sufficient to wash and cook with.

Desalinisation plants can cater to household demand for water in coastal Karachi and Gwadar. There are challenges. For instance, the fault, given the unhappy experience in Gwadar, probably lies with the public administration and concerns technical assets, because a private plant has been selling water to the government using a desalinisation plant.

Atmospheric water generators can provide cost-effective drinking water to isolated communities in humid climates. The devices condense water from the air by one of three methods: cooling the air below its dew point, exposing it to desiccants, or pressurising it. The condensed water can be disinfected by oxidisation and exposure to ultraviolet light, and rendered potable by adding minerals.

Commercial units that cost $55,000 produce up to 40 litres an hour of drinking water in ideal conditions. Consuming 8-12kW of power per hour, the units could be solar powered, which would make them suitable for catering to rural communities without electricity, but would also add considerably to capital costs. Until the Pakistani market sees proof of atmospheric water generators’ commercial viability, Wapda would do well to demonstrate it.

Recent findings by paleoclimatologists have identified the same beginning of the end for the Indus Valley Civilisation as Bronze Age civilisations in Egypt, Greece and Mesopotamia: drought. The government must coordinate a response to prevent a repeat. It must maintain its own water distribution channels and penalise heavily private parties who do not maintain theirs, regulate groundwater use and look to the sea and skies. Water is in the air. It offers more than a drop to drink.

The writer is pursuing a PhD in the economics of rural infrastructure.

Twitter: @ImadAhmed

Published in Dawn, August 18th, 2017


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