GMC Commissioner Chinmoy Phookan said the sites were selected because vehicles remain stationary at these junctions for considerable periods during red signals.

"These locations can be termed pollution hotspots because of the high volume of vehicular emissions. Accordingly, such areas have been identified for the project," Phookan said on Wednesday.

Of the 20 vertical gardens planned, one of the largest is coming up on GS Road near the Supermarket police point. The GMC has earmarked nearly 10,000 square feet at the junction for the project, making it the largest of the 20 proposed installations.

"We are already working on the Arya Nagar flyover and intend to complete the ongoing vertical garden works before Durga Puja. We are planning to give these vertical gardens as a Puja gift to the people of Guwahati," Phookan said.

A major focus of the project is selecting plants suited to Guwahati's changing climatic conditions and capable of helping mitigate pollution.

"We have decided to use only heat-resilient plants and species that can help in curbing pollution. But constructing the gardens and putting in plants is not enough. The bigger question is how to sustain them," the GMC commissioner said.

To ensure the plants survive and the gardens remain functional over the long term, the GMC has roped in agencies including the Guwahati Jal Board and APDCL to facilitate the required irrigation and power infrastructure.

"Proper irrigation is essential for sustaining these gardens. Therefore, agencies such as the Jal Board and APDCL have been brought on board," Phookan said.

The project is being implemented under the National Clean Air Programme (NCAP) of the Ministry of Environment, Forest and Climate Change, Government of India.

Phookan said the initiative goes beyond simply constructing and beautifying the sites, with long-term maintenance forming an integral part of the project.

"This is not merely a construction project. Operational maintenance is also an important component. The agency that constructs the vertical gardens will also be responsible for maintaining them for the next five years," he said.

The GMC is also exploring ways to make the vertical gardens financially sustainable by converting them into income-generating assets through advertising.

"We also intend to convert these vertical gardens into income-generating assets through advertising and other such avenues," Phookan said.

The vertical garden initiative is aimed at using otherwise underutilised concrete spaces around traffic junctions and flyovers to introduce more greenery into the city while addressing pollution concerns at locations with high vehicular density.