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ENVIRONMENTAL MANAGEMENT, ENERGY CONSERVATION & GREEN BUILDING                                                         DISASTER PREPAREDNESS, MITIGATION AND REHABILITATION



                                                                                                                                INCREASING CITY RESILIENCE


                                                                                                                                - by Chennai Metropolitan Water Supply and Sewerage Board, Tamil Nadu







                                                                                                                                          ater shortages and droughts have always been a part of Chennai's water history and the city water
                                                                                                                                          supply is impacted by the poor North-East monsoon and the dwindling storage of its reservoirs. The city
                                                                                                                                Wdoes not have any perennial water source and the city's four main reservoirs are primarily rain-fed and
                                                                                                                                are affected by the vagaries of the monsoon. The other two important water sources viz. Telugu Ganga Project
                                                                                                                                (Krishna water from Andhra Pradesh) and Veeranam lake (Cauvery Water) are not only dependent on rainfall but
                                                                                                                                also affected by political issues.  As part of the drought contingency measure, Chennai Metropolitan Water Supply
                                                                                                                                and Sewerage Board (CMWSSB) had to explore the possibility of augmenting the supply from both conventional and
                                                                                                                                non-conventional sources.

                                                                                                                                Source diversification is imperative to address the scarcity of the need.  Establishing desalination plants, converting
                                                                                                                                abandoned quarries as water reservoirs, promoting wastewater reuse by establishing Tertiary Treatment Reverse
                                                                                                                                Osmosis (TTRO)  Plants, conversion of abandoned wells and bore wells into rain water harvesting structures are
                                                                                                                                the few alternatives CMWSSB adopted to minimise the water demand-supply gap.


      Grey water recycling


                                                                                                                                BACKGROUND:                                           ESTABLISHMENT OF PRIORITIES:
                                                                                                                                Chennai is a metropolitan city and the capital of Tamil   Ÿ Making  Chennai  a drought proof city during failure
                                                                                                                                Nadu. It has an area of 426 sq km and a population of 7.5   of monsoon
                                                                                                                                million.  Chennai  has  a  dense  industrial  cluster  and
                                                                                                                                                                                      Ÿ Augmentation of additional water source
                                                                                                                                ensuring an uninterrupted water supply is vital for their
                                                                                                                                viability. While the water sources remained constant, the   Ÿ Introduction  of  Reduce  –  Recycle  –  Reuse  (RRR)
                                                                                                                                demand  has  been  steadily  rising.  It  is  increasingly   concept for sustainability
                                                                                                                                becoming difficult for the water managers to cater to the
                                                                                                                                                                                      Ÿ Uninterrupted  supply  of  treated  wastewater  to  the
                                                                                                                                growing water demand with the existing water sources
                                                                                                                                                                                        industries, thereby facilitating industrial growth and
                                                                                                                                alone. The demand-supply gap is 300 to 400 MLD and
                                                                                                                                                                                        employment
                                                                                                                                hunting for drinking water was a challenge to the citizens
                                                                                                                                of the city.                                          Ÿ Reducing over-exploitation of groundwater and avoid
                                                                                                                                                                                        sea water intrusion into groundwater aquifers
                                                                                                                                KEY DATES:
                                                                                                                                                                                      Ÿ Reducing  the  stress  arising  due  to  vagaries  of
                                                                                                                                Dates      Significance Achievement
                                                                                                                                                                                        monsoons.
                                                                                                                                (day-month-
                                                                                                                                year)
                                                                                                                                                                                      CMWSSB  is  supplying  potable  water  to  Chennai  city
                                                                                                                                25.07.2010  Commissioning of Desalination Plant at Minjur
                                                                                                                                                                                      from its water treatment plants having a total capacity of
                                                                                                                                22.02.2013  Commissioning of Desalination Plant at Nemmeli
                                                                                                                                                                                      1494  MLD  which  are  located  at  Kilpauk,  Redhills,
                                                                                                                                01.10.2019  Commissioning of TTRO Plant at Kodungaiyur
                                                                                                                                                                                      Chembarambakkam,  Surapattu  and Vadakuthu  and  the
                                                                                                                                29.11.2019  Commissioning of TTRO Plant at Koyembedu
       Grey water reuse – Apartment complexes
                                                          { 66 }                                                                                                                 { 67 }
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