NEW YORK -- Some are flimsy heaps of cardboard draped with bedsheets or garbage bags. Others are more substantial -- shacks built from wood scraps, tall enough to stand in. A few sport ragged decorations: a front porch built of milk crates, a bucket of plastic flowers, a piece of linoleum underfoot.

All of them are homes -- of sorts.

Shantytowns, a phenomenon once associated with the Great Depression, are a familiar sight again in parts of New York. In the shadows of the city's skyscrapers, the homeless are improvising shelter.

Fire hydrants provide water. Buckets and bushes serve as toilets. Light and heat come from candles and trash-can fires. Plastic tarpaulins keep out the rain. Electricity is sometimes tapped from streetlights.

"We eat from garbage cans. Sometimes people bring us sandwiches. We pick up cans and bottles to sell. That's how we survive," said Julio Ayala, who built one of a dozen huts along the East River in Lower Manhattan.

"Sometimes the snow gets inside, but the next day it's sunny," said Hector Quita, a gray-bearded man who has lived for two years in a shantytown on a vacant East Village lot.

Quita has a kerosene heater, a brick floor and a sign outside his door proclaiming the ramshackle village "Bushville." A larger encampment a few blocks away, dubbed "Dinkinsville" after Mayor David Dinkins, was razed by the city in mid-October.

Both names recall the "Hoovervilles" of the 1930s, shantytowns found all over the country and named for President Herbert Hoover.

The estimated 100 shantytowns found around New York today are much smaller, according to the Coalition for the Homeless. They each shelter 10 to 40 people and account for just a fraction of the city's estimated 70,000 homeless. But they have become a symbol of how entrenched the homeless problem is.

"Homelessness is worse in the 1980s and 1990s than it has been in 50 years, and that's why we're seeing these shantytowns again," said Kenneth T. Jackson, a Columbia University history professor. "The difference is, there was considerable sympathy in the 1930s for Hoovervilles."

In contrast, today's shantytowns are by and large ignored -- unless the residents make trouble or the land is needed. Then the bulldozers are called in.

"We weigh the size of the encampment, the hazards and the complaints we've received," said Michael Kharfen, director of the mayor's community assistance unit. "There's no set formula, but some are more urgent than others."

A shantytown in Riverside Park was dismantled because the state Department of Transportation was planning construction for the site.

A camp near the entrance to Central Park at Columbus Circle was swept away after urine seeped into the ventilation system of a nearby building.

A squalid encampment in Tompkins Square Park was torn down because it made the park unusable by others, and "Dinkinsville" was razed after neighbors complained of fires, drug dealing and fights.

In each case, Kharfen said, social workers were sent in beforehand to let the homeless squatters know about city shelters, food stamps and treatment programs.

But equally visible shantytowns are left alone -- so long as the neighbors don't complain. Quita's shantytown is across the street from a public elementary school. Shacks on a Hudson River pier face the USS Intrepid, an aircraft carrier that has been turned into a museum.

Mattresses and tarpaulins nestled under the stone parapets of a Brooklyn garage are a few steps away from a city jail. The streets around the Port Authority bus terminal are lined with cardboard beds and shopping carts full of broken umbrellas, dirty blankets and other ragged treasures.

A shantytown hard by the Manhattan Bridge has practically become an institution since artists built a teepee there a year ago. Residents now hand out postcards picturing the settlement, and a photograph of it appears in a Municipal Arts Society brochure.

"You've got to find a better excuse to get rid of these people than the fact that they're an eyesore," said Gabriele Schafer, one of the artists who created the teepee. "The last time we kicked nomadic people out -- the Indians -- we hated them too... . The homeless have a right to be left alone."

But critics are divided over whether it is more humane to let the shantytowns be, or to raze them because no one should live like that.

"Homeless people who live this way are harmed by it," said Richard Salyer, president of the New York chapter of the Volunteers of America, which runs a shelter for 800 homeless men.

"We've taken thousands of homeless people in the last few years out of airports, the subway system, tunnels and other places," he said. "It's a myth that they'd rather live in a shantytowns and bus terminals. They really shouldn't be there, even if they say they want to live this way. They need to be coaxed into accepting services, and the majority don't go back, provided they have alternatives."

But tearing down the shanties doesn't help, said Diane Sonde, head of Project Reachout, which helps the mentally ill homeless.

"They just pop up somewhere else," she said. "You're not resolving the problem by tearing the shantytowns down. You're just moving it."

She acknowledged that the city sends in social workers before the bulldozers. But she questions whether the city's shelter system provides the kind of refuge shanty residents want.

"Most of the homeless don't want a bed in an armory-style shelter with hundreds of others -- and for legitimate reasons," she said.

"I don't like the shelters," said Pepe Otero, 66, when asked why he preferred living in a shanty. "They put bad people and good people together in there. Two of my friends got killed."

He and other shanty residents -- some alcoholics or drug addicts, others simply down on their luck -- say they try not to think about where they would go if bulldozers suddenly appeared at their door.

"Life's a chance," said John Wilson, 47, who has lived for two years in a wood shack on a Hudson River pier. "It's like crossing the street. One day chicken, the next day feathers."