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Today's Paper | September 17, 2024

Published 19 Jul, 2024 07:54am

Conserving water, preventing floods

WATER is an essential commodity and is central to life for sustenance. In the Middle East region, water is taken to be more precious than elsewhere because of its shortage there. In Iran, small ponds, or ‘hawz’, used to be a compulsory part in every home. Usually, they are symmetrically positioned axis pools used for a range of purposes. The United Arab Emirates (UAE) is also working on various water modification techniques, like cloud seeding and solar-powered desalination plants, for drinking and agricultural purposes.

Pakistan is blessed with many water reserves, but we have yet not exploited these to our optimum advantage. Water scarcity in the country, especially in the sprawling cities, is becoming a serious concern. Aquifer recharge from monsoon water is a technique that is nothing but a natural solution that should be given due attention in the country.

Considering the shortage of water and the upcoming monsoon, we can take several steps to tackle water scarcity and flooding caused by rains every year. In Lahore, for instance, all drinking water is extracted from aquifers that used to be recharged from the water of Ravi. In 2000, India constructed the Thein Dam on Ravi, and, as a result, the recharge capacity had immediately gone down seriously. After the construction of Shahpurkandi Barrage this year, it has ended almost completely.

The average daily consumption of water in Lahore is 480 cubic million gallons. The underground water level in Lahore was lowered by 800 feet, as was revealed by chairman of Judicial Water Commission in 2019. After 12 feet, there is no water. The groundwater table in Lahore has been depleting at a rate of three feet every year, which is a rather alarming situation.

In 2015, a group of engineers in Lahore found that at 43 different places 1,000-acre feet volume of water used to get accumu- lated on the roads after rains. This could be stored in underground wells. In this way, the roads could also be saved from damages caused by inundation. The idea was environment-friendly as well.

They dug two such wells with an amount of Rs1.5 million. Each well measured 6×9×8 feet. In its base they spread a two-feet-wide layer of stone and a one-foot layer of crush and sand. Under that, a pipe with one-foot bore was extended to underground water. Surprisingly, in the first rain, the wells had sucked 100,000 litres of water within three hours. As a result, the traffic flow became smooth in quite a short time on these roads around the offices of the Pakistan Cricket Board at the local Gaddafi Stadium.

Moreover, the water stored in those wells, after getting filtered through the layers of stone, crush and sand, got purified and, as tested by authentic laboratories, it was usable. After one rain, the underground water table was recharged to the level of 3.5 feet.

If such wells are built in Lahore and replicated in other large cities, their collective cost can actually be far less than constructing a single huge flyover. Such methods will also help prevent expenditure incurred for the repair of roads that are destroyed during heavy showers.

As was the practice in the past, such wells can and should be planned on open spaces and public parks to store rainwater. A similar approach adopted by schools, colleges, universities and factories having open spaces would ensure the availability of recycled water across the year. There is no downside of any kind to the plan at all.

Ghazala Anbreen
Islamabad

Published in Dawn, July 19th, 2024

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