A major environmental, coastal and urban protection plan
Measures for the safeguarding of Venice and the lagoon
The problems - Over the last few centuries, a series of natural phenomena and factors due to man’s interventions have profoundly altered the lagoon environment. Over the course of time, eustasy and subsidence have drastically modified the relationship between land and water with a loss of land level of about 25 cm just in the last 100 years. Although just a few centimetres, this is actually quite a lot for a city that rests on the surface of the water. The interventions for the deviation of the rivers from the lagoon (from the XIV to the XIX centuries), carried out in order to confront the problem of sedimentation, almost completely eliminated the renourishment of sand and sediments from the hinterland. The construction of the outer breakwaters at the inlets, which occurred between 1800 and 1900 with the aim of ensuring the passage of modern ships, also reduced the quantity of sediments brought in by the sea. Over the course of the twentieth century, the creation of the petrochemical centre of Porto Marghera and the excavation of deep navigation canals provoked the emission of a sizeable quantity of pollutants and profound modifications to the lagoon hydrodynamics.