A recent Geographic Information System (GIS) study has warned that if the second airport for Chennai comes up in Parandur, it could be prone to flooding whenever it rains heavily. The study by Dayanand Krishnan, a Chennai-based GIS consultant, who has worked on several government projects including the Chennai Metro Water and Greater Chennai Corporation (GCC), used a map from 2016 to identify the flood risk of the project site. The region had experienced a flood in 2015.
The Parandur site is filled with large water bodies and in the future, during heavy rains, it has the potential to inundate the airport runways as there will be no water bodies to act like natural drainage systems, Dayanand said. According to him the implementation of the project disregarding these risks would cause repercussions.
GIS mappers use hardware and software tools to store, visualise, analyse and interpret geographic data. It is often used to address important challenges like climate change, urbanisation, and deforestation.
For a comparison, Dayanand also used GIS to study Pannur in Thiruvallur district using a map from the same time frame. It showed small water bodies, less in number compared to the large water bodies in Parandur. Parandur, a collective region of 13 agricultural villages in the Kancheepuram district is earmarked for the greenfield airport while Pannur is located in the Thiruvallur district. The government had selected four sites for the project including Pannur. However, Parandur was finalised in 2022.
Dayanand, a civil engineer, has experience in carrying out GIS studies for flood mitigation in Chitlapakkam and Medavakkam localities from 2019 to 2023. Currently, he is working in Velachery locality, one of the worst hit areas during the Michaung Cyclone.
Speaking to TNM, Dayanand said that a lake that spreads over 500 acres was close to one of the runways in the proposed Parandur project and it will be difficult to control the flood surplus of such a big lake.
According to him, Pannur is still a viable option for the state government. “Pannur is easier to access from the city than the proposed site. Besides the lakes and ponds, two rivers run parallel to Parandur runway site while Pannur has no major water bodies near the site. Additionally, the Parandur project requires filling and grading up the site up to 5 - 6 metres whereas the Pannur site needs 2-3 metres of filling and grading,” said Dayanand.
Read: ‘No one told us we will lose our land’: Parandur residents protest Chennai airport plan
The pre-feasibility report said in Parandur 26.54% of the total area (5368.93 acres) is filled with water bodies like irrigation tanks. “The government should utilise the Parandur water bodies as a water source for Chennai rather than converting them to an airport. Water scarcity is always a problem faced by residents in Chennai and the government should also think about the future if a satellite town comes up in Thirumazhasai. The town would need the water and Parandur water bodies would be the right source to meet water needs for a new township,” Dayanand said, urging the state government to reconsider its decision to bring a second airport to Parandur.
On many occasions, ecologists have raised their concerns over this issue. Poovulagin Nanbargal, a Tamil Nadu-based environmental protection organisation, also warned that if the government goes ahead with the construction of the airport, it would be an ecological disaster.
In February, the state government issued a notification to acquire land from Podavur village, one of the 13 villages in Parandur. The residents are against the proposed project and have been protesting against it ever since it was announced in 2022.