Chennai : In Deep Water Trouble
In 2017, the number of waterbodies, both large and small, came down to 28.
The historical map was sourced from the city maps prepared by the Edinburgh Geographical Institute in 1893. The rest of the maps were sourced through land satellite images, according to the team from Anna University.
“We found that the area of the waterbodies had shrunk rapidly after 1960 and there were drastic changes in the number of lakes or ponds in the core part of the city with every passing decade,” said Samurembi Chanu, a research scholar who was part of the team. The study covered the areas between Kodungaiyur, Tondiarpet and Guindy that formed the core parts of then Madras.
L. Elango, a member of the faculty at Department of Geology, Anna University, and vice-president of the International Association of Hydrogeologists (Indian chapter), said the area of the waterbodies in the city and suburbs had shrunk from nearly 12.6 sq. km in 1893 to about 3.2 sq. km in 2017, mainly due to urbanisation.
“The 1893 map indicates the presence of a crescent-shaped waterbody from the present CIT Nagar, Teynampet, Gemini flyover to Nungambakkam along the then Mount Road. The waterbodies, namely Mylapur tank and Nungambakkam tank, covered a distance of nearly 7 km,” he said.
The study aimed at checking the implications of urbanisation and climate change over ground and surface water resources and how the shrinking of open spaces had reduced groundwater recharge.
“Vysarpadi Lake, Perambur tank, Medavakkam tank and Spurtank were some of the large waterbodies that were replaced by buildings after the 1950s. While Nandanam was along the lake bund, the present CIT Colony was a waterbody during the 1950s. Kilpauk too had big waterbodies. Many small waterbodies in north Chennai near Tondiarpet have been wiped off city maps due to encroachment and urbanisation, particularly from the 1970s. There were a few ponds near Ice House too. The Madras Zoo that was located behind Ripon building and was later shifted to Vandalur in 1980s had a huge waterbody inside,” said Mr. Elango.