Population Flight, Tourist Invasion, Nature Gang Up on Venice : Italy: City’s serenity, perhaps its very existence, are threatened. Various groups suggest possible solutions, including requiring a ticket to get in.

Along the Grand Canal, once-glorious Renaissance palaces are boarded up or hidden behind scaffolding and signs explaining that they are “in restauro”-- “under restoration.”

On narrow flagstone streets, people wearing jeans and carrying cameras far outnumber those wearing suits and carrying briefcases.

In a residential area that used to be filled with vegetable markets, hardware stores and bakeries, shops sell papier-mache carnival masks, miniature gondolas and goblets decorated with bright fake jewels.

This city, once known as “La Serenissima,” is no longer “most serene.” Its unique character--perhaps its very existence--is threatened.

“Venice has changed. It is no longer the place I knew,” said Count Alvise Zorzi, who grew up in Venice, has written its history and has been at the forefront of efforts to preserve it.

“Each time I return, I feel happy because I’m back to my roots,” said the 71-year-old historian, whose family ties to Venice go back nearly 1,000 years. “But I become sad when I have to face the concrete problems of today.”

The problems that trouble Zorzi and Venice-lovers everywhere include a shrinking population, an uncontrolled tourist invasion and the ravages of nature.

Zorzi summed up their impact: “This was once a living city. Now it’s like a holiday resort, and its future is in danger.”

At its zenith in the 15th Century, Venice was a rich and powerful state that ruled a vast maritime empire. Magnificent palaces and churches, a renowned school of artists and the charm of its watery setting made it a rival of Paris, Rome and other great cities.

Ironically, during the last half-century or so, two elements that shaped Venice--the Adriatic Sea and foreign visitors--have become the sources of many of its troubles.

Built on piles driven into the center of a crescent-shaped lagoon, Venice is disrupted regularly by high tides and floods that weaken the foundations of residences and historic buildings and leave low-lying areas like St. Mark’s Square under water.

But it is the tides of tourists that are causing much of the concern these days.

Venice attracts an average of 20,000 visitors a day, more than 7 million a year. On some days during the summer peak season, more than 100,000 clog the city, as many as two-thirds of them day-trippers who spend little money and seldom wander far from two or three major attractions, mainly St. Mark’s and the shop-lined Rialto Bridge.

While tourists pour into the city, old-time Venetians are pouring out. Since the end of World War II, Venice’s population has dropped from more than 170,000 to fewer than 75,000. The decline continues at a rate of about 1,500 a year.

“It is not easy to live in this city anymore,” Zorzi said. “One needs a great deal of heroism.”

Much of the city is shabby, in constant disrepair. For centuries, boats cleaned the canals and repaired the foundations of the houses that lined them. That stopped in the 1960s because of political and budgetary problems.

The cost of living is extremely high. Food, clothing, building materials and other goods must be brought in by boat and on foot. Garbage and other waste must be removed the same way.

Many of the huge residences have been subdivided into small apartments, but their aging plumbing and wiring have not been replaced. Flooding leaves the ground floors unlivable, and there are no elevators.

When buildings are renovated, their cost soars beyond the reach of average Venetians. Susanna Scarpa, a young tour guide, would like to live in the city, but she can’t afford $1,250 a month for a tiny, one-room apartment.

So houses and apartments are sold to wealthy foreigners or to Italians from Milan, Florence and Rome who live in them only a few months each year.

Even if the prices weren’t prohibitive, blue-collar workers and middle-class families would leave the city to follow jobs to the mainland. There, the mainland suburb of Mestre has become the region’s industrial center. Its neighbor, Marghera, has taken over much of the maritime activity. Both have surpassed Venice in population.

“What is left,” Zorzi said, “is a city that serves tourists and the wealthy. Venice cannot survive that way.”

This realization has aroused concern from the Rialto to Rome, from Europe to the United States, and has inspired a number of suggestions and plans.

The New Venice Consortium, a group of 26 Italian companies, was created in 1984 to confront the challenges of the sea. Among its strategies is a sophisticated system of mobile gates that could limit the inflow of sea water during high tides.

Reversing damage done by decades of neglect will require more money and less politics. A push is being made for a single governing authority in place of Venice’s local-regional-national system.

And what can be done about the tourist invasion? As a start, Zorzi suggests that local officials work with tour operators to spread out the dates that visitors come and to encourage them to spend time in other parts of the city besides its main attractions.

Dr. Randolph H. Guthrie of New York, president of the United States-based Save Venice, one of many international groups working to preserve Venetian art and architecture, believes more drastic steps are needed.

One possibility, he and others suggest, would be to sell a limited number of visitor tickets to the historic city. But critics fear that approach would turn Venice into a floating museum, a Disneyland with gondolas, that shuts its gates each night after the last bus and train depart for the mainland.

Another proposal is to make Venice an international city, governed by the European Parliament or some similar multinational body.

Whatever is done, Zorzi cautioned, Venice must remain a living city, accessible to everyone, and retain the charm, the traditions and the magic that made it “La Serenissima.”