In about five years, Chennai will have an additional capacity to store 5-6 thousand million cubic feet of water to cater to the city’s growing drinking water needs. The Water Resources Department (WRD) is preparing estimates for projects to the tune of ₹3,000 crore, and will soon finalise funding from the World Bank.
Various projects are being worked out in different river basins, including those of the Cooum, the Adyar and the Kosasthalaiyar, in the Chennai metropolitan area to mitigate floods in vulnerable areas and boost storage capacity to reduce water stress. WRD officials said estimates were being prepared based on the basin study, with various factors, including water availability and the average rainfall in the past four decades, being taken into account. Besides schemes to improve the surface water potential of waterbodies and waterways, the WRD has turned its attention to enhancing groundwater recharge.
Building structures such as checkdams and sub-surface dykes would be part of the proposals. These structures would raise the groundwater table and help drawal from well fields, especially during drought. Such structures would be built especially across the Kosasthalaiyar with an alluvial soil condition, which helps in replenishing the aquifer.
“We plan to improve the storage capacity of 60 waterbodies around the city through rejuvenation efforts. A bio-remediation process will also be initiated to decrease pollution in the waterbodies. We are developing schemes to meet the water demand in the next 30 years,” said an official.
Schemes are also being drawn up to transfer surplus water from other basins through pumping to meet Chennai’s water needs. For instance, the viability of pumping excess water from the Palar, which is being provided with new checkdams, to the Chembarambakkam treatment plant is being considered, officials said.
The issue of seawater intrusion into the Araniar and the Kosasthalaiyar would also be addressed.
The WRD has proposed a combination of checkdams and sub-surface dykes in the Kosasthalaiyar near the Ennore Creek and in the tail-end of the Araniar near Andarmadam.
“The funding assistance will be finalised in a few days. About 30% of the project cost approved by the World Bank is likely to be released in the first phase. The projects will be taken up in a phased manner and completed in five years,” the official said.
Published - September 05, 2020 12:18 am IST
