Chennai to run of ground water by 2020; Rain water Harvesting and desal plants only hope, say officials

Chennai:

Chennai will be among the 21 cities which will run out of ground water by 2020 and Chennai Metro Water and Public Works Department are banking on desalination plants, rain water harvesting, check dams and restoration of water bodies to ward off the impending crisis.

As Niti Aayog’s Composite Water Management Index released in June 2018 which highlights that Chennai will run out of ground water by 2020 has rang the alarm bells, a Chennai Metro Water official said that the pressure on ground water resources could be reduced once the two desalination plants with a joint capacity of 550 million litres per day (MLD) start functioning. Currently, more than 200 to 300MLD of ground water is extracted and there is a threat of the water turning saline due to excess extraction.

The official said that both the desalination plants have got environmental clearance. The price bid for 150MLD desalination plan in Nemelli is to be opened after getting the clearance from German funding agency KfW. Similarly, the 400MLD desalination plant funded by Japan International Cooperation Agency (JICA) will be ready by 2024 as a result the city will have 750MLD of water on any given day.

The stress on ground water will also be curtailed with the construction of 45MLD capacity Tertiary Treatment and Reverse Osmosis (TTRO) plant at Kodungaiyur and Koyambedu. It will soon be expanded to 60MLD. Thus we will be having 120 MLD of treated water which will given to industries, the official said.

The official also said that the focus should also be on recharging the ground water through rain water harvesting, which helps conserve and augment the storage of ground water aquifers, thereby improving the ground water table.

However, there is half-hearted measure in implementing rain water harvesting. Chennai Metropolitan Development Authority has yet to implement the recommendations by consultant Aakash Ganga Trust in the development regulations of Chennai Metropolitan Area through an amendement. The audit of rain water harvesting by the consultant was carried out following the direction of then chief minister J Jayalalithaa.

Similarly, a Water resources Department official told Express that restoration of water bodies is crucial to ensure ground water is protected. “They are restoring only 25pc of the water body. Seventy-five per cent is already encroached and polluted. If entire water body is not restored, then it will not ensure water security,” the source warned.

Factfile:

1.  Chennai will run out of ground water by 2020 according to NITI Aayog’s Composite Water management Index.

2.  Officials say the two new desalination plants with a joint capacity of 550 MLD will reduce the stress on ground water

3.  Rain Water Harvesting will recharge the ground water but CMDA has yet to implement the recommendations of consultant

4.  Water redsources Department says that the state is restoring only 25pc capacity of water bodies as rest 75 per cent is encroached or polluted