( CNN ) '' Attenzione , the wine ! '' That is an old punchline in the Weir home , thanks to plastic cups of Chianti , a low bridge and a gondolier named Marco . His concerned bark broke the spell as my wife and I smooched and gaped , moon-eyed dorks on our first night in Venice . When I told my dad I was taking my wife to Italy for our first anniversary , he snorted . `` Where you gon na take her for your 10th ? The moon ? '' He was right . It was perfect . Pigeons in San Marco , sunset over the Grand Canal , Bellinis and cheeseburgers at Harry 's . Venice entered our bloodstream that trip . But in the years since , I 've heard very different stories from disappointed folks back from their first trip to La Serenissima because the city of water and love now has too much of both . Too much water , and way too many lovers . Because this impossible city of palazzos and cathedrals is built atop wooden posts driven into the muddy floor of a lagoon , Venice has been slowly sinking since Casanova canoodled down its canals . When aquifers were tapped to build massive petrochemical plants on the nearby mainland , Venice sank faster . And then folks noticed that the sea level was on a slow but steady rise . In the 1920s , there were about 400 incidents of acqua alta , or high water , when the right mix of tides and winds drives the liquid streets up into homes and shops in the lowers parts of the city . By the 1990s , there were 2,400 incidents -- and new records are set every year . But , the Italians have a plan . It is called the MOSE Project . MOSE is an acronym for `` Experimental Electromechanical Module , '' but it is also the Italian word for Moses , a guy known for parting the sea and protecting the faithful . It 's a system of 78 massive gates mounted to hinges on the ocean floor . The gates are filled with air , and designed to rise and create a temporary sea wall . Since the plan was hatched , low-lying cities from Miami to Mumbai have taken a keen interest to see if the idea can work . Everybody is still waiting : MOSE is now 10 years behind schedule , and $ 5 billion over budget . And on one early morning in 2014 , police rounded up 35 people at the highest levels of MOSE , including Giorgio Orsoni , the mayor of Venice . While several went to prison on plea bargains , the now-former mayor is fighting charges of corruption and kickbacks . But while I went back to Venice to do a story on rising water , instead I found a surprising drama about the rising tide of humanity . People know Venice is special and fragile , so they come -- to the tune of 20 million tourists a year . Meanwhile , the watery headaches and cost of living has created a mass exodus of native Venetians : 100,000 have moved to the mainland in a single generation , and around 60,000 remain . On a busy summer day , in the most popular section of the city , tourists can outnumber Venetians 600-1 . In Manhattan , that number is 8-1 . When a cruise ship dumps thousands of people into Venice at once , they squeeze down jammed medieval streets where purveyors of overpriced pizza and cheap masks have replaced the shops of artists and artisans . Each year , more people come . Each year , less get to enjoy the city we found on that first magical night . People have been worrying about the impending death of Venice for centuries , but the place is in trouble , now more than ever . And in an age of rising seas and exploding populations , Venice is a test . A test to preserve beauty , history and harmony from the greatest threats : time , tide and greed .
Venice , Italy , has slowly been sinking . The city is testing a new system that would combat the rising tides . CNN host Giorgio Orsoni travels to the Italian city for an episode of `` The Wonder List ''