Drying up resources

When the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) first drew water from Cholavaram and Red Hills lakes in 1872, the city’s need for drinking water was 2.0 thousand million cubic feet (tmc). 

Decades later, in 1944, when the drinking water need increased by another 6.03 tmc to around 8 tmc, the Poondi reservoir was constructed. Over the next several years, the population as well as the city continued to grow, the demand for drinking water soared. However, the CMWSSB decided to increase its storage level only in 2007, when Metro Water board decided to draw water from Chembarambakkam lake in 2007, which had the capacity of 3.0 tmc bringing the total storage capacity to 11.03 tmc.

Another ten years have passed, and the city population which was 4,681,087 in 2011 has now increased manifold with the city limits constantly expanding, with more migrant workforce moving to the southern parts of the city. But, Metro Water is yet to expand its storage capacity and continues to rely on water from Veeranam, Krishna and the two desalination plants. Two years ago, during the December floods, over 250 tmc of water was washed into the sea. According to water management experts, Chennai needs at least 15 tmc of surface water to tackle the prevailing water crisis. 

Despite this, the Public Works Department (Water Resources Department) has failed to adequately maintain 45 lakes in and around Chennai. The fact remains that although there are around 50 lakes in the region, CMWSSB is able to draw only from just four lakes-Chembarambakkam, Red Hills, Cholavaram and Poondi reservoir. And, as there is a severe water scarcity, the board is now tapping water from Porur lake. 

With the remaining lakes left unattended, work on Chennai’s fifth reservoir Thervoy Kandigai in Tiruvallur district remains incomplete, due to difficulty in land acquisition. Water experts and activists express concerns over the official apathy and they opine that more number of waterbodies have been lost to construction activity and massive  encroachments. 

S Janakarajan, professor,  Madras Institute of Development Studies, who has undertaken extensive studies of waterbodies, said, “It is a fact that five decades ago, the Chennai region had over 50 lakes and 200 small tanks. However, lack of maintenance, huge encroachment and non-desilting have all led to the disappearance of such waterbodies. Porur lake bears testimony to this, as it has shrunk to a mere 100 acres from 800 acres.” He further emphasised on the urgent need to complete all pending water projects at the earliest, to tackle the demand for water which will only increase in the coming years. “If all the waterbodies had been in use for drinking water supply, the capacity 

would have been around 25 tmc of water and we will not have to rely on groundwater completely,” the expert pointed out. 

Janakarajan also suggested that a considerable number of age-old lakes like Chembarambakkam, Poondi reservoir, Porur and Cholavaram lakes should be maintained well, since the entire region relied on these waterbodies for drinking water. 

Similarly, A Veerappan, former chief secretary, Chennai region, PWD, said, “Big lakes like Chembarambakkam, Poondi reservoir and Red Hills should be deepened by three feet so that we can increase the storage level to at least 15 tmc of water, from the current storage 

level of 11.03 tmc of water.” 

Only a few decades ago, most residents of the city availed of water from around 20 water bodies in Chennai, but now the entire city is now compelled to depend upon groundwater these days, he said and added that had the officials taken proactive measures, like deepening waterbodies and maintenance works at regular intervals, the present water crisis would not have risen. 

Over the years, several thousand crores of rupees have been allocated towards enhancing water storage and management, but there is very little to show for such expensive exercises.

Mani, Superintending Engineer, Palar Basin Circle, Chennai Region, PWD, said, “Although there are hurdles, projects like Dam Rehabilitation and Improvement Programme (DRIP) are apace. As far as Chennai’s fifth reservoir — Thervoy Kandigai — is concerned, we are facing issues in procuring lands; however, it will be sorted soon.”  When asked about unused waterbodies, the SE said, “All the waterbodies can be used, but the fact is that sewage is being let into such waterbodies. Once such issues are tackled, we will take up desilting work and the water can be used for drinking.” According to him, desilting and repairing works are currently underway in the main four lakes, and refuted allegations of any misappropriation of funds.