Study explores potential of abandoned quarries in city to augment water sources
A team of researchers, including those from IIT Madras, is exploring the potential of abandoned quarries in Chennai’s southern fringes to augment water sources. Abandoned
A team of researchers, including those from IIT Madras, is exploring the potential of abandoned quarries in Chennai’s southern fringes to augment water sources. Abandoned quarries form an essential component of Chennai’s drought contingency plan. Chennai Metrowater, which maintains a network of quarries as buffer sources at Sikkarayapuram and Erumaiyur downstream of Chembarambakkam reservoir, plans to use them in the event of a poor Northeast monsoon. In the wake of declining storage in the city’s major reservoirs, renewed focus has been placed on abandoned quarries as alternative water sources. The team — led by Elango Lakshmanan, visiting faculty, Hydraulics and Water Resources Engineering Group, Department of Civil Engineering, IIT Madras — has launched a study to assess the potential of nearly 25 abandoned quarries in the southern fringes such as Tambaram, Vandalur, Nallambakkam, Tiruneermalai, Unamancheri, and Keerapakkam.
The project, funded by the Union Ministry of Science and Technology, aims at developing a cost-effective network of alternative sources. Lakshmanan said the study focuses on assessing the storage capacity, water quality, and the feasibility of linking the quarries to the nearest water supply network or even for city water distribution. Building on the success of the Sikkarayapuram quarries, the study is in progress to tap potential for more quarries. He said the quarries, which have a smaller water spread area than the 15-sq.km. Chembarambakkam reservoir, must be filled first to reduce significant evaporation loss. While the reservoir is prone to higher evaporation, quarries with an area of 0.3 sq.km to 0.5 sq.km may limit evaporation losses to 10%-20%.
Water from the reservoir must be supplied in the months immediately after the Northeast monsoon, and later shifted to quarries to optimise water sources as recommended to the Water Resources Department, he said. Meanwhile, Chennai has started receiving an increased Krishna water inflow of nearly 312 cubic feet per second after a recent visit by Metrowater and WRD officials to Andhra Pradesh. The Metrowater officials said Krishna water inflow was expected to gradually increase to 500 cusecs in a few days and help maintain the storage of city reservoirs, which now stands at nearly 47%. Though the Sikkarayapuram and Erumaiyur quarries, with a combined storage capacity of 0.7 thousand million cubic feet, are nearly 75% full, Metrowater plans to draw water from them only if the Chembarambakkam reservoir runs dry or the Northeast monsoon fails.
The BriefWire