Green campaigners in India are worried, as the floodplains of the Yamuna river are being converted into shopping malls, residential and commercial outlets and even hotels for the 2010 Commonwealth Games.
This will further choke the highly polluted river and spell danger for the city's water security, they warn.
To build awareness, a programme is being held over the weekend at Rajghat in New Delhi. It is being organized by Jal Biradari, a movement that describes itself as an Indian "national water brotherhood".
The Yamuna runs for around 1,370 km. Its source is in the Himalayan mountains at Yamnotri. It flows through the states of Delhi, Haryana and Uttar Pradesh, and merges with the Ganges at Allahabad. The cities of Delhi, Mathura and Agra lie on its banks.
Said Nitya Jacobs, a writer who has researched water issues in India: "Yamuna's floodplains are being converted into malls and residential and commercial establishments like hotels in the name of a mere 10-day-long sporting event called the Commonwealth Games (to be held in India in 2010)."
By some accounts, the Yamuna is one of the most polluted rivers in the world, especially around the Indian capital.
The river has been badly affected by the high density of population living in Delhi, the illegal dumping of untreated water and solid wastes into it, and mismanagement of projects to clean it.
Water in this river remains stagnant for almost nine months, making the situation worse.
Yamuna's floodplain is being converted to fit uses like power plants, metro stations, the Akshardham temple and the Commonwealth Games Village "in the name of development".
"This will impact the water security of the city in the long-term and change the character of the river," the group behind the event warned.
The campaign plans to begin with a study of causes of pollution of the river and the role it plays in the life of the people of Delhi.
"It will diversify into raising awareness among citizens of how to contribute to reducing pollution in the river. The campaign will also propagate rainwater harvesting on rooftops, lawns, parks and roads through people-oriented decentralized water harvesting," organizers said.
Campaigners say the river is already hemmed in by bunds that have restricted the floodplain. Many lakes and ponds in east Delhi that used to get filled by the river's floodwaters dried up when they were cut off from the river by these bunds and housing or commercial complexes.
India had worked on a Rs.10,000 million Yamuna Action Plan to improve the river and its quality. There are now plans to spend another Rs.20,000 million on a second Yamuna Action Plan.
The group is seeking the involvement of the government in decision-making, specially in managing water resources. Long-term goals include a national river revival movement and a water education movement to safeguard rivers and water "as an ecosystem."
Formed in 1998, Jal Biradari says it is concerned about "water conservation, forest-soil management, promotion of water conservation work as well as with struggle to re-establish community water rights".