Water, the elixir of life, depleting fast
India’s water security is perched in a precarious position. Even by conservative estimates, 40% of people in India will not have drinking water by 2030. According to a World Bank report, at least 21 Indian cities are moving towards zero groundwater level by 2020. Tamil Nadu is witnessing the worst drought in 140 years. All districts of Tamil Nadu had been declared as drought-affected in 2017. Chennai, in particular, faced a water crisis, primarily due to the failed North East and South West monsoons in 2016. The water supply here has been the worst in 14 years. This article discusses the serious water shortage situation in Chennai and ways to tackle it going forward.
Chennai’s water sources stressed
The four main reservoirs - Poondi, Red Hills, Cholavaram, and Chembarambakkam - together had only 89 mcft of water remaining as on July 4, 2017, against the full capacity of 89,000 mcft. All the Chennai lakes had dried up fully at the end of June 2017. The Veeranam lake in Neyveli, about 220 km away, from where Chennai receives water supply through a huge pipeline was dry too. The authorities made alternate arrangements to supply 90 million litres a day (MLD) to Chennai through the same pipeline. Hence, 22 stone quarries in Kancheepuram and Thiruvallur, two desalination plants at Minjur and Nemmeli (supplying 100 MLD each), and 300 agricultural wells became the primary water sources for the 470 MLD supplied from Metrowater.
After a period of five months, the Red Hills reservoir - the main source for Chennai Metrowater, started receiving inflow around the end of August 2017. The Chembarambakkam and Sholavaram reservoirs also started receiving water - bringing some relief. At the end of August 2017, official Metrowater sources confirmed that water distribution through pipe supply would be increased, but there would be no increase in the supply of water through tankers.
Demand Outstripping Supply
Chennai is the country’s fifth largest city and one of the fastest growing cities with 8.5 million residents within city boundaries, and an additional 2 million in the metropolitan region. According to the Census, the Chennai metropolitan area has added an average of 2,65,000 residents a year since 2000!
While the daily demand stood at 1,009 MLD, authorities had been managing to supply about 766 MLD through pipelines and lorries. This supply has been reduced to a mere 470 MLD.5 The per capita water supply was about 114 litres per capita per day (lpcd) when it should have be 135 to 150 lpcd. The suburbs get around 40 lpcd. The situation is worse in slums where supply is as low as 25 lpcd.
In many areas, piped water was supplied only once in three days. Metrowater does not cover all streets of the city through its piped supply and uses tankers to supplement water supply in the remaining areas. As per Chennai Metrowater Supply and Sewage Board (CMWSSB), water supply tankers make around 7,100 trips a day now - 70% more than the earlier 4,000 trips a day.3 In all, 300 more water tankers have been deployed in Chennai recently for its water needs.
Although the rains in November-December 2017 were good with a large excess of rainfall recorded and three reservoirs showing a marginal rise, there are many long-standing deficiencies in the entire water extraction, water protection, community care, and people’s water habits that are overall compounding this long-repeating, permanent water crisis. The actions taken by the water authorities are not that sustainable in the long run. The following aspects need to be given urgent attention to move towards sustainable water management in Chennai.
1. Greywater recycling
A lot of good quality water goes waste as it was used in bathrooms, for flushing, car washing, cleaning and gardening purposes. Dr. Sultan Ahmed Ismail of Ecoscience Research Foundation states that used-water recycling is an essential part of maintaining an eco-friendly lifestyle. Indukanth Ragade, a greywater reuse expert, asserts that recharging groundwater through treated greywater could significantly improve the quality of borewell water. It will also save on residential water expenses substantially. A law has been in force since August 2003 that greywater recycling was compulsory for all buildings to treat their grey water by organic or mechanical means and to use this for groundwater recharge or for flushing closets. However, due to lack of awareness of recycling methods, it has not been complied with by Chennai buildings and hence it has also contributed to the water crisis. CMWSSB announced in April 2017 that it is not going to give new water and sewerage connections to special and multi-storeyed buildings that do not have a facility for separating blackwater from greywater and to reuse greywater. CMWSSB estimates that 15% of Chennai’s future water requirement may be met by recycling.
2. Stormwater Drains
According to the Comptroller and Auditor General (CAG) of India's report on Urban local bodies in 2016, poor execution of key stormwater drain projects by Greater Chennai Corporation resulted in a loss of Rs. 54.33 crore to the taxpayers. More crucially, this has left Chennai unprotected during heavy rainfall season. The report also said that execution of stormwater drains by GCC was done without adequate topographical, meteorological, and hydrological studies and without ultimate linkages to natural water bodies. This had resulted in the construction of 51 new drains of inadequate size that would ultimately result in flooding of roads.
3. Extraction of groundwater
Various incentives and advice need to be given to the public to report illegal water extraction activities. Even legal extraction by civic bodies and private players has had adverse side-effects (such as economic and social consequences) on the local ecosystems. For example, due to extraction by civic bodies for Chennai’s demands, the groundwater level at Thiruvallur and Kancheepuram have sunk to 6 meters below ground level. Treating water taken from various stone quarries for supplying by Metrowater is also not advisable, say environmentalists.
4. Rainwater Harvesting
This needs to be made mandatory before granting approvals for all new buildings henceforth and older buildings need to be requested to comply. Unless groundwater is recharged sufficiently by rains, or by greywater recycling and rainwater harvesting, it will become difficult to use borewells reliably further.
5. Desilting of lakes and waterbodies
There are thousands of water bodies in Chennai and its neighbouring districts. The groundwater in Chennai and its surrounding areas is replenished by five lakes - Puzhal, Cholavaram, Kaliveli, Pulicat and Maduranthakam - all located within a 60 km radius of the city. Environmental activists assert that had all these water bodies been properly maintained, Chennai would never have suffered from such a serious water crisis and blame rapid urbanisation for the lack of upkeep of these water bodies. Ancient civilizations like Harappa and Mohenjodaro utilised wells and community tanks efficiently for harvesting and storage purposes., Thus it is essential to reuse ancient water wisdom again and view water bodies as community water storage devices that can serve Chennai water during droughts. With the local community’s awareness and support, going forward, Chennai water bodies must be revived and maintained well.
6. Reducing unnecessary water consumption
An estimate shows that the per capita usage of water is around 135 litres per day for regular domestic activities. This needs to be reduced further by responsible usage and by using efficient household appliances and water delivery devices. However, there are not much regulations now for water-delivering device manufacturers to follow specified efficiency norms and this gap has to be corrected soon to save unnecessary transmission losses. Consumer behaviour towards water availability needs to be studied carefully and design of devices and water delivery systems need to be appropriately modified so as to produce water-efficient devices, home appliances and municipal water supply systems.