CHENNAI: IN a bid to bring back the age-old ‘eri system’ for groundwater recharge -- by restoring water bodies and interconnecting them -- the 100 Resilient Cities programme has drawn up proposals, in partnership with the Greater Chennai Corporation, to revamp the Kovalam-Muttukadu Basin and the Mambalam Canal.
The initiative is spearheaded by experts from the Dutch government and the Dutch special envoy for international water affairs. They have created a detailed plan put forward by both Dutch and Indian experts belonging to various fields of urban design, social engagement and water conservation.
In the first project called Rise Chennai, two locations, namely Kovalam-Muttukadu Basin and Mambalam Canal, have been chosen based on landscape, to recharge the aquifer to the best possible extent. Also, a feasibility report and a detailed project report will be submitted soon to the Chennai River Restoration Trust, which is the main point of communication to the government for this project.
25 km long basin
This basin runs along for 25 kilometres from Pallikaranai Marshland in the North to Kelambakkam in the South with thickly populated stretches of ECR and OMR, forming its backbone. The plan is to restore water bodies across this basin and connect them through water channels that will finally drain into the Buckingham Canal.
“We have identified 1000 acres of OSR land in SIPCOT and more pockets of land in ELCOT which can be used to link the water bodies to the Buckingham Canal. Also to avoid water bodies from getting encroached during summers, they can used as playgrounds, parks or for irrigation and grazing purposes,” said Uthra Radhakrishnan, a member from IIT Madras’ Indo-German centre for sustainability and a core member of the project.
People part of the Rise Chennai team, said that this will done in the Kovalam Basin mainly by constructing wetlands on empty pockets of land and through the Eri system by restoring water bodies. The primary focus is to maximise the utility of Poramboke land as wetlands for aquifer recharge, said Jayashree Vencatesan, founder of Care Earth Trust, the main member who is aiding this part of the project.
“We chose Muttukadu as it is the location where Chennai is going to expand further. Also, its coastal and historical characters are two attributes that share water as the common factor. Wet areas need to be conserved the most as they witnessed peak urbanisation since 1980s,” said Jayashree.
1200 hectares watershed area
The canal which has a watershed area of 1200 hectares and has around eight lakh people living around it, can provide about 80 MLD of water if redesigned and cleaned-up, said experts.”The canal is full even during the summer, indicating a huge inflow of sewage from surrounding areas. This can be made to stop by installing sewage treatment plants of small capacity along the canal and plug sewage outfalls,” said Hans Gehrels, a senior water specialist part of the team.
Also, existing apartments built by the Tamil Nadu Housing Board along the canal will be demolished and replaced by adaptive buildings that are flood resilient in nature and that can conserve rainwater and reuse grey water.