Decks cleared for a sixth reservoir in Chennai
Since the mandatory CRZ clearance has been obtained, the new reservoir will be constructed at Rs 471 crore, covering 4,375 acres. The reservoir will have a depth of 3 metres and store 1.655 TMC water.
State Water Resources Department
CHENNAI: Decks cleared for Chennai's sixth reservoir as the Tamil Nadu State Coastal Zone Management Authority (TNSCZMA) has issued CRZ (Coastal Regulation Zone) clearance to Water Resources Department (WRD) to create the reservoir for drinking water purposes near Thiruporur. The approval was given during a meeting of the authority a few days ago.
Since the mandatory CRZ clearance has been obtained, the new reservoir will be constructed at Rs 471 crore, covering 4,375 acres. The reservoir will have a depth of 3 metres and store 1.655 TMC water.
As per the proposal, the reservoir will serve drinking water needs of 12 villages — Nemmeli, Krishnankaranai, Pattipulam, Saluvankuppam, Paiyanur, Thandalam, Kalavakkam, Thiruporur, Thiruvidanthai, Punjeri, Kadambadi, Mamallapuram — and extended CMA areas. The peripheral flood carrier drains will improve natural drainage and reduce inundation.
Even though the TNSCZMA gave its nod, the WRD should adhere to certain conditions including the creation of natural vegetation along bunds and ensuring no sewage, sullage, industrial effluent or untreated discharge enter the reservoir.
The WRD should also obtain a no objection certificate (NOC) from the Fisheries Department, ensuring no negative impact on traditional fishing activity, and that the project should not impair navigation or drainage function of Buckingham Canal. The project also should not affect water sports activities at Muttukadu backwaters.
The new reservoir will have an overall catchment area of 41,408 hectares (ha), of which 29,642 ha are intercepted by a cascade system of 69 tanks in Thaiyur, Manamathy, and other minor groups.
Meanwhile, a demand assessment study conducted for the project has estimated that the present GCC area would require 1,702 MLD (million litres per day) of drinking water by 2035 and 2,178 MLD by 2050.
CMA’s water demand will go from 387 MLD to 821 MLD by 2035
Moreover, the rest of the Chennai Metropolitan Area (CMA) would require 821 MLD and 1,568 MLD by 2035 and 2050, respectively.
In 2020, the water requirement for GCC and the rest of CMA was at 1,333 MLD and 387 MLD.
The WRD applied for the clearance as the proposed reservoir site lies in the close proximity of the Shoreline and is directly a tidal influenced water body, and falls in the CRZ IB and CRZ IVB, which mandates CRZ clearance. The formation of fresh water recharge structures and tidal regulators is a permissible activity in the CRZ regulations, but with consent.
The Chennai Metropolitan Water Supply and Sewerage Board (Metro Water) draws drinking water from Poondi, Cholavaram, Redhills, Kannankottai Thervoykandigai and Chembarambakkam. The lakes have a total storage capacity of 11.757 TMC. The new reservoir will be the sixth one for the city. Moreover, water from Veeranam lake in Cuddalore district is utilised for the city's drinking water needs, apart from desalination plants in Nemmeli and Minjur. Works are ongoing for a 400 MLD desalination plant at Perur on East Coast Road.