Unfolding Narratives

Special Feature
rainwater harvesting
Marking a Sustainable Future
Rainwater Harvesting is more about a need for
planning and incorporating systems at the
construction stage than mere high technology
Anurag Yadav
March 22 is celebrated globally as World Water Day. In
India, this day needs to be marked with still greater
emphasis for obvious reasons. Water scarcity in Delhi,
Mumbai and other metros is appalling and the crisis in smaller
towns can be critical indeed. With increasing worldwide focus on
climate change it is no wonder that sustainable initiatives such as
water harvesting comes centre stage. A typical commercial
rainwater harvesting system in one building can save millions of
liters of municipal drinking water each year. That savings could
quickly add up to billions of liters per year if public and private
buildings are enforced, incentivised or encouraged towards it.
Now let’s face the facts. Few private buildings and government
buildings too, barely spared a serious thought for water harvesting.
So far it has been a localised sporadic effort because closely linked
to rainwater harvesting is the issue of reusing grey water.
There have been many but one example of the country’s previous
first citizen will illustrate it best. In November 1998, the then-
President of India K R Narayanan evinced interest in harvesting
water at the Rashtrapati Bhavan campus which covers 1.33 sq.
kms. The total demand was about 2 million liters of water per day.
This demand was met through the New Delhi Municipal
Corporation supply and the estates own borewells.
Since about 35% of the water requirements were being met through
groundwater sources, there had been an alarming decline of
groundwater levels in the estate. Simply by diverting rainwater
from the northern side of roof and paved areas surrounding
Rashtrapati Bhavan to an underground storage tank of 1 lakh litre
capacity a substantial saving was made. Recharge shafts were
constructed in the staff residential areas and a dramatic rise in
water tables was noticed in a few years.
Today, it is a still more commercially sensible decision to invest in
rainwater harvesting technologies in commercial and private
buildings. In fact rainwater harvesting and grey water reusage
should go in step.
Architecture Update March 2016 19