Flood will help govt pilot project on water conservation

NEWDELHI:The surging Yamuna might have temporarily displaced thousands of people but the inundated banks has come as a shot in the arm for the Delhi government, which recently started a pilot project to conserve flood waters to recharge the depleting ground water aquifers on the floodplains.

This is a first-of-its-kind project in the country, which aims to conserve excess water flowing down the river during the monsoon by creating a mega reservoir in the floodplains between Palla and Wazirabad.

“Some of the reservoirs, through which water would percolate down to the aquifers, have already been constructed by digging out top layer soil. They are all inundated now and this would help us. Once the water recedes, we would start ascertaining the rate of percolation. This is the first step of the project,” said a senior official of the irrigation and flood control department.

Artificial reservoirs are being created on the Yamuna plains of one metre depth in which floodwater will be collected. This water will gradually recharge and come back to Yamuna through a natural process.

The peak demand of water in Delhi shoots up to around 1150 MGD during summer. The Delhi Jal Board can produce only around 936 MGD. This results in an acute water shortage. The ground water in several parts of Delhi is also ‘over-exploited’.

“During the monsoon season, at least six lakh cusecs (around 3.5 lakh MGD) of rainwater flows down the Yamuna every day. If we can conserve this water in the river’s floodplains, it would help us to solve Delhi’s water problem for almost a year,” Kejriwal had said while laying the foundation stone of the Chandrawal Phase-2 water treatment plant.

Due to farming and other activities, water was unable to

go beneath the surface. But there is a layer of sand beneath that which helps water to percolate faster. In this project, the top soil has been removed up to a depth of around one to oneand-half metres to allow faster percolation. “We have set up piezometers in the dug-up reservoirs to ascertain the rate of percolation,” said a official of the Irrigation and Flood Control department.

Views of experts in the field of water conservation and recharging vary from whether water percolates at a speed of two metres per day or 10 metres per day.

›

During the monsoon season, at least six lakh cusecs of rainwater flows down the Yamuna every day. If we can conserve it... it would help us to solve Delhi’s water problem for almost a year ARVIND KEJRIWAL, Delhi CM