By Lucy Gibson
“It is generally accepted among environmental geographers that there is no such thing as a natural disaster. In every phase and aspect of a disaster—causes, vulnerability, preparedness, results and response, and reconstruction—the contours of disaster…is to a greater or lesser extent a social calculus” (Smith, 2006:1)
While Neil Smith wrote these lines in respect to Hurricane Katrina, a similar perspective can be taken for the increasing occurrences of flooding in Chennai. Reflecting on the 2015 flood events, Sud (2015) noted that “climate change is not the only guilty party”. Certainly, climate change is one factor, but the scale of the disaster in Chennai was magnified by rapid urbanisation and a disregard for the importance of water bodies in town planning. For example, over 273 hectares of the Pallikarni marshland are now covered in buildings, the floodplain of the Adyar river is now Chennai’s international airport, and Chennai’s famous Information Technology and Knowledge Corridors sit atop wetlands and marshlands. Areas which would normally act as sinks for flood water are rapidly decreasing.
Velachery Lake is another example which shows that urban planning must consider the importance of water bodies for a more sustainable future.
Velachery is a growing residential area in southern Chennai. The growth of the neighbourhood can largely be attributed to the growth of the IT sector. However, this dramatic increase in the size of the urban population and consequent spatial expansion of residential areas have fundamentally changed the physical landscape for Velachery.
Historically, Velachery Lake was spread over 250 acres. Today, its water spread area has been reduced drastically by 80.5% with residential and industrial complexes now occupying the area. Due to its low-lying location, rainwater from neighbouring areas drain into Velachery Lake; however, every November, Velachery is flooded by monsoon rains. The reduced water storage capacity of Velachery Lake is a significant contributor to this flooding.
The decline in the geographical size, physical, chemical, and biotic properties of water bodies have affected urban ecosystems, biodiversity, and the aesthetics of the landscape. Additionally, the occurrence of flood disaster during the monsoon seasons in Chennai must be correlated with the spatial allocation of water bodies. Approximately 650 water bodies have been destroyed in Chennai; compared to the city’s 2,847km of urban roads, there are only 855 km of storm drains.
Moreover, the master plans created by Chennai Metropolitan Area’s urban planners reveals the perceived insignificance of water bodies to the area’s urban development.
In fact, the area allocated for water bodies is negligible; while the area allocated for residential and institutional spaces increased by 23.27% from 1971 to 2009, the proposed Master Plan of 2026 makes no mention of the spaces covered by water bodies.
Additionally, Velachery Lake has suffered from the dumping of garbage and untreated sewage water into its waters, further reducing the storage capacity of the lake and polluting its waters. In 2018 the Chennai Corporation put a hold on the proposal for boat rides and other tourist facilities due to the high level of contamination of the water. With about 2,000 families living in the southern bund, and pipelines directed to the lake, the waste, high in organic matter, directly increased the chemical and biological oxygen demand in the receiving waters. The higher the chemical and biological oxygen demand, the greater the potential for damage to biological life living in the water.
Yet, there is great potential and urgent need to protect Velachery Lake from further encroachment and pollution, improve its the current conditions and safeguard the water body, and other water bodies, for future use. As of August 2020, to prevent the outbreak of any vector-borne disease the Chennai Corporation has started cleaning water hyacinth from the lake using an aquatic weed-cutting boat that helps cut underwater weeds, clear silt, and remove garbage. This work is currently being carried out on Velachery Chinna Eri, one of the two areas making up Velachery Lake
Urban water bodies are important natural resources. They act as flood moderators, serves as drinking water sources and recreation centres, but only if preserved properly. Water sector planning needs to be an integral component of metropolitan planning for the benefit of the future.
Without this, sustainable urban development will remain a distant thought.