VENICE, Italy — The first of five blasts from the sirens atop St. Mark's bell tower and other high points in this lagoon city sounded late one night in early April, unusually late for the high tide season.
The alarm woke many Venetians and tired tourists and let night owls know they would have wet feet if they didn't make it home in a couple of hours before the acqua alta--high water--flooded in.
In Venice, life and the sea are inseparable.
The municipal tide prediction and warning center shares the second floor of a Grand Canal palace with City Hall's marriage room. While brides and grooms exchange vows in a front hall, technicians in the back room pore over computer printouts of sea conditions and moon phases.
Lately water seems to be overwhelming the Venetians.
The high tide on April 8, for example, struck many as unusual. Normally, residents say, acqua alta comes during daytime, not in the dead of night. And the high tide "season" is generally considered over by spring, although experts insist July is just about the only "dry" month.
When the water recedes, "you're left with a sense of death," says Giorgio Lombardi, an architect whose apartment's sweeping view takes in San Michele island, the city's cemetery.
He keeps a pair of high rubber boots at home and another in his office. If he's out with a client when the lagoon waters happen to roll in, an aide sloshes out to bring him another pair.
"One evening I left my studio with two clients from South America. They started yelling 'Fantastico!' when the water came surging up over their knees," Lombardi recalls.
For Venetians, the relentless high tides eat away at more than the wooden doors and shutters of ground-floor apartments.
"The water remains in your soul. Venetians say 'enough,' and then they go away," Lombardi says.
City officials dispute that. They argue it's Venice's high cost of living and not frequent flooding that is mainly to blame for the dwindling of the population from 175,000 a half century ago to about 70,000 now.
But the decades-old debate on how to save Venice is wearing down those who do stay.
Last fall dozens of shopkeepers pulled on rubber boots for a protest march on St. Mark's Square demanding that something be done about acqua alta.
Trouble is, everybody seems to have a different idea about what should be done. In fact, not all agree on what the problem is. Some say the acqua alta phenomenon is getting worse. Others argue that some years are simply more punishing than others.
High tides of 32 inches or more flooded Venice a record 101 times in 1996. The next year, there were 79 such floods.
And the high tide is often higher than ever. Although nothing has come close to the 6 1/2-foot depth during the city's disastrous 1966 flood, there have been other whoppers.
Last November, the month of the merchants' "boot" protest, the tide surged to nearly 5 feet.
"It's true, in the last 20 years the height has increased," says Franca Pastore, who has been analyzing data at the tide warning center since shortly after it opened two decades ago.
But "it's too early to say if there's an alarming" trend, she says. "Many contend these are cyclical phases."
What is sure is that the level of the Adriatic, whose waters flood Venice, has risen by 9 inches over the last 50 years, after being more or less stable for decades.
The rise is blamed in part on melting glaciers as well as on heavy draining, until the 1970s, by local factories of underground water, causing the city to sink.
In Venice, whether the day will be easy or hard often is measured in quarter inches.
When the tides rise too much, the boats that serve as Venice's "buses" cannot pass under bridges. And when the tide swells above 4 feet, the city's sanitation collectors are not allowed to lay down the nearly 3 miles of raised wooden walkways near schools, courthouses and along other main routes to keep pedestrians' feet dry. The gangways could be swept away by the high waters.
On the drawing board for more than a dozen years has been Project Moses, a plan to install mobile barriers on concrete beds on the sea floor at key points in the lagoon where the Adriatic pours in. The barriers would be raised as a temporary dike when high tides were predicted.
Named after the biblical prophet who saved his people from drowning while crossing the Red Sea, the project has a $2.6-billion price tag.
In 1998 the Italian government said no to Moses after a study committee said the barriers could have irreversible ill effects on the lagoon's environment.
Supporters continued to push the plan, and earlier this year the national government said that perhaps other steps could be taken that would reduce the number of times the tidal barriers would have to be raised.
One such "small" intervention is expected to begin soon: the raising of St. Mark's Square, one of the most flood-prone points, by about 4 inches.