The encroachment and lack of maintenence of our water bodies and wetland complexes was one of the major reasons behind last year’s floods in Chennai. Experts continue to express concerns about the city’s ill-preparedness to cope with the monsoon this year as well. Most storm water drains have not been de-silted, the height of roads continues to be raised, and there is no check on garbage and sewage being dumped into water bodies. Encroachments by private and commercial entities remain unchecked. Unless significant steps are taken to restore our water bodies, we will continue to face man-made disasters that will only continue to rise in proportion. Dr. Jayshree Vencatesan, Managing Trustee, Care Earth Trust, says the biggest issue in addressing the cause of lake restoration is that the process is being generalised. “You need to characterise wetlands, and the restoration pattern has to be specific for every zone. The city has to be characterised from a hydrological viewpoint, ” she says.
Here is a list of seven such water bodies that need a specific restoration plan:
In 1972, this water body was nearly 214 acres. A GIS mapping today shows that only 20 acres are left. Over the years, SIDCO Industrial Estate and SIDCO Nagar have come up right on the banks of the lake, shrinking it by almost 80 per cent over the last three decades. During the 2005 floods, most of the water drained into the lake and the area did not have a major problem. However, preliminary analysis of the GIS data has now revealed significant encroachments on the lake over the last three years. Since 2014, the dumping of Metro Rail construction debris into the lake has further led to its deterioration. This has prevented rain water and excess flood water from being stored in it, resulting in the flooding of SIDCO Nagar for about 15 days during last year’s floods . Even today, storm water drains in the area are completely choked up with silt, garbage and debris in many places.
It is a fresh water lake spread over 600 acres and experts believe it can be used to solve Chennai’s water problems if it is maintained properly. The Korattur wetland is an extensive wetland with good water depth and a well-defined boundary dotted with palmyrah trees. The lake has been encroached at many places and waste and sewage is being dumped in by several commercial establishments and builders. The wetland supports a significant population of turtles and amphibians, so there are concerns about how to protect habitat diversity. There is some illegal hunting that goes on here. The lake is also being used as a dhobi ghat.
The lack of a buffer zone around the wetland has resulted in the rise of a number of residential zones on its edges, and this has gradually eaten away the fringes of the wetland. A surface water quality analysis conducted in 2013 suggests the presence of a very high concentration of chemicals such as lead, mercury, cadmium, and chromium.
This lake has been split in two by the 200 Feet Road and a badminton court, and a temple constructed illegally. Water hyacinths need to be removed to increase the holding capacity of the lake. On the channel connecting Kilkattalai and Narayanapuram lake — except for the initial 100m stretch — the waterway has been heavily encroached on one side by private residences that have reduced the channel’s width to 40 feet or even 15 feet at many places from a original width of 60 feet. The entire stretch is clogged with garbage and construction debris, resulting in floods.
Pallavaram Periya Eri
There are two major water channels that connect west Chrompet to the east at Pallavaram Periya Eri. The length of the Kattabomman canal has been reduced to 7 feet from its original 33 feet. The Durgai Amman canal has also been completely encroached. The natural gradient is from the west to east of GST Road and any blockage in these canals results in flooding of the area. The channels connecting Chrompet to the Pallavaram Periya Eri used to be anything between 30 and 60 feet wide, but have been heavily encroached today. The Eri on the Chrompet side has been encroached (about 70 per cent) by residential developments while the Pallavaram Municipality uses 20 per cent as a garbage dump. The National Green Tribunal has ordered the Pallavaram Municipality to clear the garbage and reinstate the lake but work hasn’t started yet.
Fifty years ago, it was spread across 6,000 hectares, but only about 600 hectares remain today. The Pallikaranai - Velachery stretch was one of the worst hit areas during the 2015 floods and this was because the entire area is only 0 to 2 metres above sea level and water from all other lakes run down the gradient into the marsh. Experts say the area is not suitable for residential development but it has yet seen tremendous residential growth. Poor urban planning over the last two decades, encroachments, and pollution are other factors that have further led to its deterioration.
Of the Buckingham Canal’s 13 km stretch that was to be expanded, only a 4 km stretch has been expanded from 20 metres to 100 metres. Along the other 9 km, it has been widened from around 25 to 45 metres only.
The entire channel connecting Thirupananthal and the Adyar River has been encroached by builders and private houses going beyond their approved plot sizes and shrinking the channel to 4 feet to 6 feet width in the first 50 metres. Completely choked with silt, plastic waste, and garbage, the channel’s flow has been affected significantly. The channel ends at a small pond in Pammal that is filled with construction debris. The overflow from here is diverted into two very small channels that are poorly maintained and mixed with sewage.
Popular spots in the 80s, the Chitlapakkam and Sembakkam Lakes functioned as important irrigation sources. Water from the lakes was used to fill tanks in Sembakkam and Hasthinapuram. Over the last many years, the lakes have been filled with garbage, sewage, and hospital waste. The Chitlapakkam Lake has been reduced to 40 acres from its initial 80 acre expanse. Increasing road height in the area also results in floods every monsoon.
With inputs from Arappor Iyakkam and Care Earth Trust