![venice the sinking city venice the sinking city](https://i.ytimg.com/vi/k2gOAntAFPM/maxresdefault.jpg)
After the land surface dropped nearly 30 feet, injection stabilized the subsidence and a slight rebound in land surface elevation (a little over 30cm) was even seen in some spots. Injection was used successfully in Long Beach, California in the late 1950s to halt subsidence caused by oil and gas extraction as well as groundwater usage.
![venice the sinking city venice the sinking city](https://static.thousandwonders.net/Portofino.original.12243.jpg)
It’s not entirely a two-way street-much of the pore space lost during compaction can’t be recovered-but increased pore pressure can begin to unpack the sediment. Just as withdrawing groundwater can cause subsidence, injecting water can reverse it. Recently, another idea has been discussed. As a result, the land surface is sinking, and the salt marshes are suffering for it. In a natural setting, this compaction would be offset by the deposition of fresh sediment at the surface, but the rivers feeding the lagoon were diverted in the 1500s. Like other cities built on river deltas, the sediment beneath the city is compacting over time. In short, the sea is rising and the city is sinking. Two factors are exacerbating the flooding risk to the city: global sea level rise and subsidence. When that coincides with a high tide, the City of Water gets even wetter, and the water level can rise by 1-2 meters. The region sometimes experiences unusually high tides, locally referred to as “acqua alta.” The phenomenon is caused by winds that drive water to “pile up” on the north end of the long and narrow Adriatic Sea. Its waterlogged nature draws a steady stream of visitors, but also makes it vulnerable to costly flooding. Built in a lagoon along the coast of Italy, the scenic city is crisscrossed with canals. The city of Venice has long been valued for its unique character.