From Floods to Drought: Chennai's Water Crisis

Chennai, the capital of Tamil Nadu, is facing a severe groundwater crisis that threatens its sustainability. Recent data from the Water Resources Department (WRD) shows that 26 districts are experiencing a significant drop in groundwater levels compared to last April, exacerbating the critical water shortage across the state.

The western districts of Tamil Nadu have been hit hard. In Dharmapuri, the average depth of groundwater dropped from 5.78 to 8.98 meters this year. Namakkal saw a similar decline, with levels dropping from 6.15 to 9.34 meters. Salem, Krishnagiri, and Tiruppur are also experiencing significant depletion.

Coimbatore is one of the worst-affected areas, with water levels dropping from 9.4 to 10.85 metres compared to the previous year. Chennai has seen an average dip of 0.5 metres in groundwater levels. Other districts with substantial declines include Perambalur, Tiruchy, and Tirupattur.

The situation is dire in many parts of the state, but there is a positive aspect for some southern districts. Due to heavy rainfall during the northeast monsoon, Tirunelveli, Tenkasi, Thoothukudi, and Virudhunagar have seen an increase in groundwater levels. However, this improvement came with flooding.

Groundwater depletion affects farmers, especially in western regions known for cash crops like groundnut and coconut. K Balasubramani, general secretary of the Tamil Nadu Vivasayigal Munnetra Kazhagam, expressed concern over the state's insufficient promotion of rainwater harvesting.

Chennai's water woes

The situation in Chennai is alarming. Many residents found their borewells running dry even before summer officially began. S Velu, a resident of Selaiyur, saw both his borewells fail in April. Despite digging a new 600-foot borewell, he was unable to find water and now relies on water tankers and municipal supply.

According to "Excreta Matters," a 2012 study by the Centre for Science and Environment, Chennai has over 0.42 million wells. Only 27,000 are open wells, extracting 150 million litres per day (MLD) of groundwater at an average rate of about 400 litres per well per day. Additionally, around 66% of households in the city have their own private wells.

This extensive extraction has led to a general fall in water levels and a decline in average yields per well. Between 1991 and 2002, groundwater levels fell at a rate of slightly less than one metre per year. The rate accelerated between 1999 and 2004 to close to two metres annually.

Roots of water crisis

Chennai's water crisis has worsened due to rapid urbanization and climate change. The city has expanded from 48 square kilometers in 1980 to over 426 square kilometers today, causing significant environmental damage, especially to the wetlands.

The Pallikaranai Marsh, once a vital part of Chennai's natural water system, has lost 90% of its area to urban development in the last 50 years. It was part of a complex hydrological system covering 186 square kilometers, including rivers, backwaters, coastal estuaries, and mangrove forests. An assessment by the NGO Care Earth Trust found that Chennai lost 62% of its wetlands between 1980 and 2010.

According to the report of the World Resources Institute, The destruction of these natural water bodies has depleted wildlife habitats and created a paradox where Chennai faces both water scarcity and flooding. During the monsoon, the city receives 1.5 times more rainfall than it consumes annually. However, paved surfaces prevent rain from replenishing groundwater, while stormwater drains rush water out to sea.

As per the report, mismanagement of water resources led to the severe 2019 water crisis in Chennai, when the city ran out of water. Government trucks had to deliver water to roadside tanks, causing long queues and occasional violence. Ironically, in 2015, the city experienced devastating floods that killed at least 470 people and displaced hundreds of thousands.

Legislative efforts and shortcomings

Chennai has attempted to address its groundwater issues through legislations:

1. The Chennai Metropolitan Water Supply and Sewerage Act, 1978 aimed to promote planned development of water supply and sewerage services.

2. The Chennai Metropolitan Area Groundwater (Regulation) Act, 1987 made Chennai the first Indian city to regulate urban groundwater use. The act covered the city and 302 surrounding villages. It required registration and licenses for non-domestic water extraction and transportation.

3. The Chennai Metropolitan Area Groundwater (Regulation) Amendment Act, 2002 tightened the rules from 1987.

4. The Tamil Nadu Groundwater (Development and Management) Ordinance, 2003 prohibited water transportation from notified areas without permission and established the Tamil Nadu Ground Water Authority.

Water scarcity has continued to increase despite efforts. The Chennai Metro Water Board has resorted to extracting water from peri-urban villages, violating its own regulations. This has led to tensions between rural communities and Chennai, and among rural communities themselves.

A 2018 research paper in "World Development" highlighted how the Board's strategy of purchasing riparian water permits in neighbouring districts has created conflicts. Some farmers profited from selling their water rights, but many others, especially small and marginal farmers, have been negatively affected, relying on shared groundwater aquifers for agriculture.

Looking ahead

Chennai's water crisis requires a multifaceted approach. Balaji Narasimhan, a hydrology professor at the Indian Institute of Technology Madras, emphasizes the need to allow rainwater to replenish groundwater reserves instead of rushing it out to sea.

Experts stress the importance of preserving and restoring the city's natural water bodies and wetlands. Their destruction has contributed to water scarcity and increased flood risk during heavy rains.

There's a growing recognition that Chennai's water issues are interconnected with surrounding rural areas. Any sustainable solution must consider the needs of both urban and rural communities and the balance of shared water resources.