Flood waters will help pilot project on water conservation in floodplains

Artificial reservoirs are being created on the Yamuna plains of one metre depth in which floodwater will be collected.

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. (HT image)

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 the 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, who is associated with the project.

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.

“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 in June 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 one-and-half metres to allow faster percolation.

“We have already set up piezometers in the dug-up reservoirs to ascertain the rate of percolation,” said a senior official of the Irrigation and Flood Control (I & FC) 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.

“The speed of recharging will be measured. The area till which underground water reaches will also be ascertained. This will form the basis of launching the project on a bigger scale next year once when results of the pilot are known,” chief minister Arvind Kejriwal had said when the pilot project was being launched.