The capital city of Pakistan faces one of its most extreme water crises throughout its sectors.
Water tankers roaming the metropolitan have become a familiar sight. Khanpur and Simli Dams, designed to supply water for the Islamabad of 1970s and ’80s, are failing to provide adequate amount of water needed for the city’s ever-growing population. Citizens are forced to take matters in own hands, relying on privately drilled water wells or bores. This provides a temporary solution to people’s problems. However these wells are well on their way to be dried out. Bores need sufficient amount of infiltrated water to remain functional but most of the rainwater is incapable of reaching the underground water table in time to rejuvenate them. It can take months to even years for water to infiltrate to ground water table. We need to give back before taking more.
While the city is depleted with its water supply, rain is pouring down in ample amounts. Where bores are expensive and short term, rain water harvesting is a limitless and available source of water. This practice works passively by diverting rainwater falling on our rooftops and storing it in our underground tanks below for use.
On average, Islamabad receives 1,100 millimetre rainfall per year. A standard 10 marla house which has a surface area of 250 metre square can harvest 275,000 litres of rainwater on yearly basis. This amount of water is sufficient to provide a family of seven round the year. Inhabitants can use this supplementary source instead of relying on limited water supply and bores. Underground tanks can be scaled up to a storage of 25,000 litres, enough water for a family’s monthly usage. Meanwhile, excess rainwater can be also diverted to dead bores for recharging. Rainwater harvesting can recharge a dried out well to its original state in a couple of years. The hydrating process for our ground water table which previously took months can be reduced to a matter of minutes.
Harvesters also gain some health benefits since rainwater is purer than groundwater and is free from salinity, making it considerably safer for potable usage.
Islamabad is not a complete stranger to rainwater harvesting. In 2010, the iconic Faisal Mosque introduced its water harvesting project capable of collecting 3 million litres of water on a particularly rainy day. The project proved to be well successful and paves a hopeful path for the rest of the city to follow. Under proper guidance the capital shows much potential to turn its environmental crises on its head. From mass plantation of trees to introduction of sensible water conservation, we’re growing towards a greener Islamabad.
Published in Daily Times, September 1st 2018.