Zaida Bibi squatted by the side of an open drain, pounding her family's wash in a metal bucket.

We have very much trouble getting water here," she said as other residents of one of Calcutta's 3,000 official slums crowded around the tap, which carries running water just three times a day.

Down the packed dirt walk, which turns into a sea of mud in monsoon season, another woman was slapping hamburger-like patties of cow dung against the wall of her brick hovel so they could dry to be used as cooking fuel. The smell of the cow dung permeated the southeast Calcutta slum of Darapara, where about 20,000 people live.

The area has no electricity, and disease is rampant. Dr. K. M. Allarakha, who runs a private clinic near the water tap, said most of his patients suffer from food poisoning because of the spoiled fish and vegetables they eat.

Still, with their houses, they are the lucky ones. Thousands of people in this most crowded of Indian cities live on the pavement, often curled up in rags against the side of the building or sometimes under crude lean-tos with roofs of plastic sheets that are set against building walls.

Besides having proper brick housing for most of its residents, the Darapara slums is in the midst of change as part of the wide-ranging improvement program of the Calcutta Metropolitan Development Authority.

Latrines, which until recently had to be emptied by buckets with the human wastes dumped in an open field nearby, have now been replaced with flush toilets. Deep drains are being dug both to carry off excess ground water during the rainy season and to handle the sewage.

The walks will be bricked, with runoff drains, and outdoor lights will be installed.

Perhaps most important to women like Zaida Bibi, who now line up three times a day to get buckets of water for washing, cooking and eating from the 10 water taps in Darapara, more outlets will be added and the pressure will be increased so they can run all day.

There is now one tap for each 2,000 residents, and the improvement program aims to increase that to one tap for each 50 residents -- a total of 400 taps for Darapara.

The plan seeks to meet the most basic needs in what it calls "the largest slum improvement program in the world."

"We never accepted that Calcutta is a dying city," said Kalyan Biswas, who heads the Metropolitan Development Authority.

His group is trying to salvage Calcutta, not rebuild it. It runs slum renewal programs, not slum clearance.

"We keep the slums, but improve the environment," said Biswas.

Calcutta's efforts stand in sharp contrast to some of the massive urban renewal projects in the United States, such as Southwest Washington. It also differs from the slum clearance program favored in Delhi by Prime Minister Indira Gandhi's late son Sanjay, who moved thousands of residents of poor neighborhoods to sparse resettlement colonies outside of the city that have become new festering slums.

According to Biswas' figures, the development authority since 1971 has tackled 1,700 of Calcutta's 3,000 official slums -- called bustees in India -- in which 1.7 million people live. By next March, he expects to have improved slums where 2 million people live.

The change between unimproved slums and ones in which the Metropolitan Development Authority has worked is staggering.

The north Calcutta neighborhood of Paikpara hardly deserves to be called a bustee any more after improvements were made in 1975. It is a neat, clean colony whose residents are mostly poor day laborers earning about a dollar a day.

There are no smells there. The walkways are brick, and the residents appear to take pride in their tiny homes -- a 10-foot square room houses a family of six -- painting and decorating the exterior.

Children, playing with plastic yo-yos, laugh as they follow visitors down the street instead of looking solemn as they do in Darapara. They appear healthier and look cleaner.

"Before there were unhygenic conditions. There were few taps, no lighting system, no sewage. Now people are much less sick," said Salil Ghosh, the secretary of the community center at Paikpara.

Predictably, however, the landlords raised the rents from a little more than $2 a month to double that once the improvements were completed.

The Metropolitan Development Authority has spent $435 million on revitalizing Calcutta -- $61.25 million on slum improvements alone -- since it was started 10 years ago with Ford Foundation seed money. More than $36 million came from World Bank loans while other funds were provided by the government of West Bengal State and the central Indian government.

Despite all of these efforts, Kipling's description of Calcutta as "the city of dreadful night" still seems true today. The Statesman, an English-language newspaper published here, called this city "an urban disaster" because of its overcrowding; its chaotic, traffic-clogged streets, and its poor housing conditions.

Nothing, for instance, is planned by the Metropolitan Development Authority for the untold tens of thousands -- or perhaps hundreds of thousands -- of Calcutta residents whose only home is a patch of sidewalk. They can be seen during the day with their meager belongings wrapped up beside them. When darkness comes, they crawl into a blanket -- if they are lucky enough to have one -- and go to sleep.

It is the highly visible pavement dwellers and those who live one step up, in the sidewalk lean-tos, that give Calcutta its reputation as a black hole.

Yet Biswas said the real source of Calcutta's poor reputation is the city's economic decline since independence, when Calcutta was a major industrial center and India's busiest port. Even though Calcutta has diminished as an industrial giant, he said it still can climb up.

And one way to help it is to rejuvenate the city. For more than 50 years, according to Biswas, Calcutta has been starved of funds needed to maintain municipal services. Even now, the city government argues it does not have the money to maintain improvements that the Metropolitan Development Authority pays for.

During that time it has faced two mass migrations of refugees that swelled the already crowded city.

Still, Calcutta survived and remains, said Biswas with the pride of a native, "the most livable city in India."

"It's more of a state of mind than any other city. You tend to have a sense of belonging to it. Either you love it or you hate it."