Making the most of a rainy day
It is estimated that, on a rainy day, every square mile of urban land causes 16 million gallons of rainwater to be washed into rivers. Harvesting rainwater can help recharge and replenish the groundwater system. This helps in both checking flooding and handling water shortage.
How can we use rainwater more effectively?
With an aim to becoming water-sustainable, we try to harvest 100% of the rainwater in our campuses. Rainwater from surface runoff as well as building rooftops is harvested through lakes, and deep injection well systems.
Collection tanks
Rainwater from the roof is treated and then directed into underground collection tanks. The collected water is filtered and treated in the treatment plants across our campuses before use.
Deep injection wells
Rainwater that is collected and directed deep into the ground through injection wells helps to raise the groundwater tables. We have built 149 deep-injection wells across our campuses. These have a combined recharge capacity of about 2 million gallons per day.
By raising the groundwater levels, these wells not only benefit us, but also the communities residing in the areas surrounding our campuses.
Artificial lakes
To augment our water harvesting capacity, we have built 25 lakes across our campuses, with a combined storage capacity of 66 million gallons of rainwater. In addition to being a water reservoir, these lakes offer a thriving ecosystem for diverse species of fauna and aquatic vegetation.
In fiscal 2015,
42%
of the freshwater requirements for one of our buildings in India was met by rainwater harvested from rooftops into collection tanks.