Cluster of abandoned quarries to be networked to form a significant storage structure for Chennai’s water supply

Chennai Metrowater proposes to network abandoned quarries to create a water storage system for the city's growing needs.

The cluster of abandoned quarries in peripheral areas, which serve as a buffer source of freshwater, may be networked to form a significant water storage structure to tackle Chennai’s growing needs.

The Water Resources Department (WRD) along with Chennai Metrowater has proposed to create an integrated network of the abandoned quarries in various areas such as Sikkarayapuram, Erumaiyur, Tiruneermalai and Chettipunyam in Chengalpattu district to tap resources for the city’s drinking water supply.

Chennai Metrowater already has created infrastructure to draw about 30 million litres of water a day (mld) stored in Sikkarayapuram quarries and convey to the Chembarambakkam treatment plant through a 3.5 km-long pipeline. Sources in the Metrowater noted that water from the nearly full quarries was supplied Chennai to prevent inundation in neighbouring areas during Northeast monsoon last year.

In a move towards water secure Chennai, the project is aimed at tapping sources during drought as in 2019, and decentralise water supply network to enhance resilience against impact of climate change.

A proposal is being chalked out to network the cluster of abandoned quarries to create a storage structure with a capacity to hold nearly 4,000-5,000 million cubic feet of water (mcft). The network of quarries would have similar or higher than the storage capacity of the major reservoirs such as Chembarambakkam.

The five major reservoirs have a combined storage capacity of 10,569 mcft of water.

Sources in the WRD noted that the feasibility of diverting floodwater from Palar river to Uthiramerur quarries would also be explored during preliminary investigation. The channel created to divert surplus water from Chembarambakkam reservoir to Sikkarayapuram quarries would be improved as a cut and cover channel. Water pumped from the networked quarries, which could serve as a sustainable reservoir system, would be linked to existing Chennai Metrowater’s grid.