ISLAMABABAD – Islamabad, the capital city of Pakistan faces one of itsworst water crises.
Water tankers roaming the metropolitan have become a familiar sight.Khanpur and Simli Dams, designed to supply water for the Islamabad of 1970sand ’80s, are failing to provide adequate amount of water needed for thecity’s ever-growing population. Citizens are forced to take matters in ownhands, relying on privately drilled water wells or bores.
This provides a temporary solution to people’s problems. However thesewells are well on their way to be dried out. Bores need sufficient amountof infiltrated water to remain functional but most of the rainwater isincapable of reaching the underground water table in time to rejuvenatethem. It can take months to even years for water to infiltrate to groundwater table. We need to give back before taking more.
While the city is depleted with its water supply, rain is pouring down inample amounts. Where bores are expensive and short term, rain waterharvesting is a limitless and available source of water. This practiceworks passively by diverting rainwater falling on our rooftops and storingit in our underground tanks below for use.
On average, Islamabad receives 1,100 millimetre rainfall per year. Astandard 10 marla house which has a surface area of 250 metre square canharvest 275,000 litres of rainwater on yearly basis. This amount of wateris sufficient to provide a family of seven round the year.
Inhabitants can use this supplementary source instead of relying on limitedwater supply and bores. Underground tanks can be scaled up to a storage of25,000 litres, enough water for a family’s monthly usage. Meanwhile, excessrainwater can be also diverted to dead bores for recharging. Rainwaterharvesting can recharge a dried out well to its original state in a coupleof years. The hydrating process for our ground water table which previouslytook months can be reduced to a matter of minutes.
Harvesters also gain some health benefits since rainwater is purer thangroundwater and is free from salinity, making it considerably safer forpotable usage.