Harvesting system saves 20m gallons of water

Karachi has been experiencing unprecedented amounts of monsoon rainfall for the past three years, causing urban floods in various parts of the city and inundating entire neighbourhoods, which have to be drained out at the cost of millions.

However, Aman Khan Kakakhel, who runs a charity called Satun Niki, believes that excess rain, although a bane for the city, can be turned into a boon through a process of rainwater harvesting that would help mitigate the growing water crisis in Karachi.

Putting his theory to test, Khan has so far been able to conserve up to 20 million gallons of water, saved from various parks, streets and private housings. "Water crisis exists in many cities around the world. The only difference is that while other countries address the crisis by figuring out ways to conserve what they lack; we waste the resources we have. There are various ways to conserve rainwater, among which rainwater harvesting is one method that is easy and most affordable," said Khan.

The idea of rainwater harvesting came to Aman Khan some five years ago, when he first introduced concept within his own neighbourhood of North Karachi Sector 11E. "The area had been struggling with an acute water crisis for past many years. There was a 200-foot boring that was dug, but water would only flow for five minutes. There were two wells set up in a public park close to our house, but they too had dried up," recounted Khan, while talking about his neighbourhood's ordeal prior to his rainwater conservation efforts. "All we had to do to remedy the crisis was save all the rainwater that was being wasted and flooding our streets. We installed 6-inch and 8-inch pipes, running from the sides of the park to the wells, so that the rainwater from the sides would fall into the wells. In this way, rainwater does not accumulate on the sides of the park and we are able to save up to 3 million gallons of water in the two wells and 300 borings on the sides are recharged for six months, in a single rain spell," he added.

This set up, according to Aman Khan has costed around Rs30,000 to Rs40,000 to build and sustain, and has significantly elevated the area's ground water table. Per Khan, a set up like such is perfect for cities that are built on concrete and do not have capacity for dams, owing to which instead of reaching underground table, the water either floods the streets or goes into the gutter and is wasted.

While on the other hand, owing to the water supply shortage, the city's urban residents continue to draw water for their use and commercial institutes for commercial purposes from the thinning groundwater table, which hasn't had enough time to replenish itself. "This is not good for the environment. By recharging these wells, not only the underground water is being protected but we are also preventing the possibility of land erosion. Rain harvesting will restore the ecological system and strengthen the underground structure," commented Khan.

According to Aman Khan, he has so far installed his rainwater harvesting systems at thirty different locations around the city, a majority of which include water starved slums. "It took about two million rupees to bring this project to fruition, and it has been able to conserve over 20 million gallons of water this season. If the provincial government and local bodies cooperate with me, we can make expand the project citywide. If rain harvesting technology is implemented in the entire city, Karachi will become self-sufficient in fresh water and will be spared from this destruction in the monsoon season," he told The Express Tribune.

Published in The Express Tribune, July 20^th, 2022.