Introduction and Background
The district of Kancheepuram is located in the state of Tamil Nadu. The district spans an area of 36.14 square km. This district houses one of the State’s well-known artificial lakes which formed due to the collection of rainwater over the years – the Chembarambakkam Lake (Eri). The full tank capacity of the lake is 108 million cubic meters. In reference to Chennai, the Kanchipuram district is around 40km from the city lying between 13º0’22’ North 80º3’35’ East. (Figure 1)
Figure 1: Chembarambakkam lake – Location
Geologists and archaeologists trace the history of the lake to over thousands of years. According to the stone-tool evidence found on the banks of the Chembarambakkam Lake, scientists believe that early humans migrated from Africa to India over a million years ago, where they might have moved from West Asia in small groups to the South Asian region. This mobilization could have expanded to the Chembarambakkam Lake region. Evidence of such a settlement along the banks of the lake can be seen from the palm-held axes of the Lower Palaeolithic found in the lakebed (Chandrasekaran, 2018). This suggests that some water bodies existed at that time, and it could have been a lot different from what the lake appears today.
Studies published later suggest that the lake was built by Rajendra Chola I, the son of Rajaraja Chola, and Thiripuvana Madeviyar, prince of Kodumbalur, which was filled with water during subsequent rainfalls. Chembarambakkam was known as Puliyur Kottam and was one of 24 villages during the Chola period in Thondai Mandalam, in which Kancheepuram was the capital. For centuries, the water-fed the paddy fields along its banks and was used for irrigation purposes. The Adyar river originates from the lake and presently, automotive companies dot the fringes of the lake.
Present condition & issues pertaining to the Chembarambakkam lake
As mentioned above, initially the water from the lake was used for irrigation and helped about 13,500 acres of land in 39 villages. Over the years, due to rapid urbanization, the agricultural lands have been covered with concrete and the lake presently provides only drinking water (Kumar, 2020). Environmentalists and scientists have also identified that the capacity of the lake has been reduced to 60% of its initial capacity due to sedimentation and waste dumping (Vithaspa, 2020). In 2019, first time in several decades, efforts to clear silt were taken which would eventually make room for 536 million cubic feet of water storage. (The Hindu, 2019)
Water from the lake is distributed through canals after treating the water. There are two pipelines existing from the lake’s water treatment plant. The existing one on Poonamallee Road can only convey half of the lake’s capacity and hence, the Chennai Metrowater proposed the construction of the third pipeline at INR650 million (Barath, 2019). The new pipeline is under construction and is expected to be completed in 2022 (The Hindu, 2021).
In 2018, Physico-chemical parameters of the Chembarambakkam lake in summer and monsoon were recorded and the results are tabulated below.
Table 1: Physico-chemical properties of Chembarambakkam Lake
|pH@25ºC: Alkalinity is good for the growth of aquatic organisms.||6.5 – 8.5||7.67||8.78|
|Turbidity (NTU): Increased turbidity causes decreased light penetration, plant growth, and oxygen production in the water, which can reduce the survival of aquatic animals.||5.0||90.1||0.2|
|Electrical conductivity (µS/cm): EC is controlled by the geology of the area where the water body is situated, the size of the watershed, wastewater from sewage treatment plants, wastewater from septic systems, urban runoff from roads, and agricultural runoff.||–||488||205|
|Total hardness (Mg/l): High values of hardness are probably due to the regular addition of large quantities of detergents draining into the water bodies.||600||51||56|
|The distribution of nutrients (Ca, Mg, Fe, Cl, S) is due to the season, tidal conditions, and freshwater flow from land sources.|
|Total dissolved solids (Mg/l)||2000||360||94|
|Biochemical oxygen demand @25ºC (Mg/l): The high BOD might be due to the decomposition of organic matter and decay of vegetation in rivers that mixed seawater during the rainy season.||–||6.86||Below Detection Limit|
|Chemical oxygen demand (Mg/l): High COD due to runoff from the surrounding areas of the lakes.||–||95.1||39.2|
|Dissolved Oxygen (Mg/l): The partially dissolved oxygen in water depends upon the partial pressure of gas in the air close to water, the rate of photosynthesis, and the oxygen holding capacity of water.||–||0.98||1.1|
|Manganese (Mg/l)||0.3||Below detection limit||Below Detection Limit|
Figure 2: Lake through the years from 2016 to 2019 and the percentage of water area
During the water crisis of 2019 in Chennai, the Chembarambakkam Lake dried up and the city was parched. Figure 3 gives a comparative picture of the lake in 2018 and 2019
Figure 3: A satellite view of Chennai’s water crisis of 2019
Several concerns have been raised as to how the effluents have resulted in the poor water quality in the lake (Chembarambakkam Water Treatment Plant, n.d.). In addition, the water itself has dried up owing to rapid urbanization and exploitation of the water. The main cause of the water drying up in 2019, can be attributed to urbanization and the unreasonable run-off of rainwater into the sea during the 2015 floods. Lack of proper water and disaster management has impacted the water in the lake. It is important to note that the lake itself is dependent on rainwater and thus, there is a need for water management through policy-making to ensure that rainwater is collected and distributed with no wastage across the State from the lake. Further, the water collected in this lake keeps the Adyar river alive, impacting the biodiversity around the river.
Biodiversity of the Chembarambakkam lake
- Zooplankton Species (Altaff, 2019)
Rotifers, Cladocerans, Ostracods, Nauplii & Copepodids, Calanoids, Cyclopoids, Harpacticoids, Mysids
- Reptile Species (Tsetan & Ramanibhai, 2011)
Ahaetulla nasuta (Common Vine Snake), Atretium schistosum (Olivaceous Keelback), Bungarus caeruleus (Common Krait), Coelognathus Helena (Trinket Snake), Daboia russelii (Russell’s Viper), Dendrelaphis tristis (Common Bronzeback Tree Snake), Gongylophis conicus (Common Sand Boa), Lycodon aulicus (Common Wolf Snake), Naja naja (Spectacled Cobra), Oligodon arnensis (Common Kukri Snake), Ptyas mucosus (Common Rat Snake), Xenochrophis piscator (Checkered Keelback Lizards), Calotes versicolor (Indian Garden Lizard), Hemidactylus brooki (Spotted Indian House Gecko), Hemidactylus frenatus (Southern House Gecko), Lygosoma punctata (Dotted Garden Skink), Eutropis bibronii (Sand Skink), Eutropis carinata (Common Skink), Eutropis macularia (Bronze Grass Skink), Sitana ponticeriana (Fan-throated Lizard), Varanus bengalensis (Common Indian Monitor Turtle), Lissemys punctata (Indian Flapshell Turtle)
- Molluscs (Johnpaul et al., 2010)
Pila, Thiara, Sulcospira, Paludomus, Indoplanorbis
Altaff, K. (2019, June 20). Zooplankton diversity of freshwater lakes of Chennai, Tamil Nadu with reference to ecosystem attributes. International Journal of Life Science, 7(2), 236-248. https://oaji.net/articles/2019/736-1561403054.pdf
Barath, E. (2019, December). Degradation of Chembarambakkam Lake’s Water Surface Area. International Journal of Engineering Research & Technology (IJERT), 8(12). https://www.ijert.org/research/degradation-of-chembarambakkam-lakes-water-surface-area-IJERTV8IS120060.pdf
Chakravartty, A. (2019, June 25). One of India’s biggest cities has almost run out of water. The Independent. Retrieved February 26, 2022, from https://www.independent.co.uk/climate-change/news/india-chennai-water-reserve-lake-puzhal-drying-up-monsoon-a8971211.html
Chandrasekaran, A. (2018, October 10). Tamil Nadu’s Chembarambakkam Lake Foretells an Aridity in the Sands of Time. The Wire. Retrieved February 26, 2022, from https://thewire.in/the-sciences/tamil-nadus-chembarambakkam-lake-foretells-an-aridity-in-the-sands-of-time
Chembarambakkam Water Treatment Plant. (n.d.). Water Technology. Retrieved February 26, 2022, from https://www.water-technology.net/projects/chembarambakkam/
The Hindu. (2019, September 12). After decades, government begins desilting Chembarambakkam lake. The Hindu. https://www.thehindu.com/news/cities/chennai/after-decades-government-begins-desilting-chembarambakkam-lake/article29395875.ece
The Hindu. (2021, June 19). Work to lay pipeline from Chembarambakkam water treatment plant will be accelerated, say Metrowater Managing Director. The Hindu. https://www.thehindu.com/news/cities/chennai/work-to-lay-pipeline-from-chembarambakkam-water-treatment-plant-will-be-accelerated-say-metrowater-managing-director/article34861585.ece
Johnpaul, A., Ragunathan, M. B., & Selvanayagam, M. (2010). POPULATION DYNAMICS OF FRESHWATER MOLLUSCS IN THE LENTIC ECO – SYSTEMS IN AND AROUND CHENNAI. Recent Research in Science and Technology, 2(4), 80-86.
Kumar, V. (2020, November 25). Chembarambakkam holds freshwater and scare for Chennai. The Federal News. https://thefederal.com/states/south/tamil-nadu/chembarambakkam-holds-freshwater-and-scare-for-chennai/
Narain, S. (2015, December 4). Why better sewage management in Chennai will help fight floods. Down To Earth. Retrieved February 26, 2022, from https://www.downtoearth.org.in/coverage/why-better-sewage-management-in-chennai-will-help-fight-floods-51993
Thangamalathi, S., & Anuradha, V. (2018, September). Seasonal Variations In Physico – Chemical Parameters of Seven Different Lakes In Chennai, Tamil Nadu, India. IOSR Journal of Environmental Science, Toxicology and Food Technology, 12(9), 11-17. 10.9790/2402-1209031117
Tsetan, C., & Ramanibhai, R. (2011, September 21). Reptilian fauna of agricultural landscapes of Chembarambakkam Lake, Chennai, Tamil Nadu. Retrieved February 26, 2022, from https://www.zoosprint.zooreach.org/ZoosPrintNewsLetter/Reptile_Rap_13_Sep2011.pdf Vithaspa, S. (2020, December 11). The Phenomenon called Chembarambakkam – Lakes of India. Lakes of India. Retrieved February 26, 2022, from https://lakesofindia.com/2020/12/11/the-phenomenon-called-chembarambakkam/