OneWorld.net (U.S.)

New Delhi: A pioneering project undertaken by an Indian NGO in collaboration with a government agency has worked wonders for a centuries-old lake in the heart of India’s capital New Delhi. The project – Revival of the Hauz Khas Lake – saw many ups and downs and fought bureaucratic indifference as it sought to fill up the lake with treated sewage water.

New Delhi-based non governmental organization (NGO) Indian National Trust for Art and Cultural Heritage (INTACH), along with the Delhi Development Authority (DDA), which controls most of urban governance in the city, came up with the bold plan to revive the 700 year-old Hauz Khas lake in south Delhi with treated sewage water. The plan was to take treated water from a Sewage Treatment Plant (STP), clean up the water to a higher degree through biological processes and transport it to the dry lake.

INTACH decided to get recycled water from Vasant Kunj – a south Delhi residential area which is over five kms away - simply because this was the only source of a reliable water supply albeit controversial. The water from the STP was taken to a forest where two lagoons were created to clean up the water further with aquatic plants like the water hyacinth and duckweed.

Water consultant Sudhirendra Sharma says: “Duckweed pond technology is a viable, cheap and natural way of treating domestic sewage. It requires a series of ponds that can hold water for at least a week in which the plants absorb the organic matter. Water quality also improves as the water moves from one pond to another. More cities should use this technology to improve the micro-climate and reduce domestic sewage.”

But the plants posed a problem as these would double in a fortnight. Arrangements were made to compost the plants and make manure out of these. Finally the DDA had to bring the twice-cleaned water from the forest to the Hauz Khas lake through a pipeline to avoid further contamination from villages and residential colonies on the way.

Though such initiatives have been taken up globally, convincing the people was tough, particularly residents, who lived near the lake. Though everyone welcomed the plan to have a big brimming lake, they turned up their noses the moment they realized treated sewage water would be used for it.

The resistance multiplied once the project took off. People shot off letters to local government officials and complained to the media. Some of their complaints included unpleasant odour, dirty water and mosquito-breeding. And morning walkers were the most offended as the lake emitted a foul smell.

A regular walker at the lake said: "There was a stinking smell about five months back. But it has not been there for some time now. Also, there is a constant flow of water here, which was not there earlier. I only hope that the stink does not begin again."

INTACH resorted to a series of innovative measures to sort out these issues.

Chief Programmes Director, Natural Heritage Division of INTACH, Manu Bhatnagar said: “We introduced a number of fish species to keep the water clean, consume algae and feed on mosquito larvae. The fish include gambusia, that feed on mosquito larve, Indian carps - rohu, catla and mrigala – that eat up organic matter and an exotic fish imported from China – the grass carp.”

As the lake has been dry for many decades, trees have sprung up from its bed. These fall and rot due to which the cleanliness of the lake is affected. DDA has posted six people to clean up the lake and ensure that nobody throws waste into it. It has introduced floating fountains so that water does not stagnate.

The Delhi Development Authority (DDA), which was established in 1957 to bring about planned urban development in the Indian capital, found the project unique and challenging. A DDA chief engineer associated with the project said: “For us it was a learning opportunity. We hardly do such projects as we are mostly into construction activity.”

The engineer added that groundwater in the Hauz Khas village has gone up by 10-12 feet and wells that were dry have revived due to percolation of water into the aquifers. It is estimated that nearly 1,000 million litres of rainwater and 750 million litres of treated sewage water have been recharged to the aquifer since the project began.

It is not only man that has benefited from the project. The presence of water in the lake has caught the attention of water birds like spot bill ducks, pochards, mallards, shovellers, grebes, gadwall goose, black-winged stilts and pintail ducks. The Delhi Bird Group, which had earlier found birds like warblers and birds of prey, now finds many more winged visitors including pintail ducks, which flew over from Siberia.

The Hauz Khas lake is an artificial lake that was made in 1305 AD and was written about by historians as being huge enough to serve the water needs of Delhi during that century. A king’s tomb and the ramparts of a historic fort currently surround the lake, adding mystery and allure to it and making the area a tourist destination.

The lake dried up a few decades back because drains that fed it were diverted. A shrinking catchment area because of urban development and residential areas added to its misery. Though the lake fills up during the rainy season, July-September, the water does not hold for long.

The Indian capital is blessed with an interesting history and a rich topography. It is also known as one of the most polluted cities in the world. The INTACH project seeks to restore some of the environmental damage that has dogged the Indian metropolis due to urbanization, massive urban projects and heavy demands on the civic infrastructure.

Sandwiched between the Yamuna and the ridge, Delhi has witnessed many legal battles over its environment, forcing the judiciary to intervene to protect Delhi's lifeline - the Yamuna - and large portions of the ridge - which are the remnants of ancient mountains that travel upto Rajasthan.

The courts also had to intervene and order the civic bodies and the Delhi government to clean up river Yamuna, construct sewage treatment plants and ensure that industrial wastewater is cleaned before it is dumped into the river. Doughty environmentalists have lobbied with the government, have filled public interest litigations (PILs) and educated people about the necessities of preserving the vital natural features of the city – the ridge and the Yamuna.

Resources on the subject: Toxics Link Sanctuary Asia