Venice Isn't Alone: 7 Sinking Cities Around the World

Many big cities sit near the ocean. They became cities in the first place because their ports facilitated trade and travel by sea.

Coastal cities all over the world are sinking — a geological process called subsidence — and it's happening at a rate that makes scientists nervous. If these bits of land didn't have important cities on them, it's likely nobody would notice, or, in some cases, that they wouldn't be sinking at all.

Subsidence happens for a variety of reasons. Often it's from extracting water, oil, natural gas or minerals from the ground through activities like pumping, fracking or mining. Earthquakes can cause subsidence, as well as erosion, the formation of sinkholes, soil compaction and other geologic processes.

All this is happening while climate change is causing ice in the polar regions of the world to melt, resulting in an increased volume of seawater in the world's oceans. Coastal cities are not only in danger of submerging, but also of natural disasters like hurricanes.

Here are seven cities that are sinking, and why.

1. Jakarta, Indonesia

Jakarta, located on the northwest coast of the island of Java, is the capital city of Indonesia, and the fastest sinking city in the world — in some places it's settling around a foot (30.5 centimeters) per year. About 40 percent of the city sits below sea level, and flooding is common, partly because of the rising of the Java Sea that surrounds it, and partly due to illegal well drilling. Scientists warn that by 2030, much of Jakarta will be uninhabitable.

Java is the most populous island in the world; freshwater is scarce and groundwater is a hot commodity. The illegal boring of wells in and around Jakarta is understandable in a city where the local government can't provide fresh water for its 9 million residents, not to mention the millions of others who commute to work in the city. But the island's wetlands are being drained by illegal wells, leading to the subsidence of the entire landscape.

Joko Widodo, Indonesia's long-time president, has proposed that the capital city be moved to a location 800 miles (1,300 kilometers) away in Borneo. The new city will be called Nusantara, and construction has already begun.

2. New York City, New York, U.S.

Today the five boroughs of New York are covered in over a million buildings, weighing approximately 1.68 trillion pounds (762 billion kilograms).

"The weight and local geology is a secondary factor in the case of New York," says Matt Wei, a geophysicist and professor in the Graduate School of Oceanography at the University of Rhode Island. "The dominant reason they city is sinking is glacial isostatic adjustment."

Glacial isostatic adjustment (GIA) is a process by which the Earth's crust adjusts in response to the melting of huge ice sheets like the one that covered North America in the last ice age. When ice sheets accumulate on land, they squash the Earth's crust beneath them. As the ice melts, the crust slowly rebounds to its original position — think of a cushion renewing its original shape after you get out of the chair you were sitting in.

New York is in an interesting position because it's actually sinking due to the fact that the last ice age caused it to rise because the heaviest sheets of ice were inland. Now that the ice has melted, the middle of North America is rising, while the edges sink.

"In New York, the average sinking is between 1 to 2 millimeters [0.03 to 0.07 inches] per year, plus 3 to 4 millimeters [0.11 to 0.15 inches] per year due to sea level rise," says Wei, who co-authored a 2023 study about New York's plight. "The relative sea level rise might be millimeters per year. Depending on the site elevation, you might expect 0.4 to 0.6 meters [1.3 to 1.9 feet] of relative sea level rise in 100 years."

3. Houston, Texas, U.S.

Houston, Texas, located on the Gulf of Mexico, is experiencing rapid subsidence. Built on the flat, low mouth of a river delta, Houston has never had far to fall in terms of elevation, but like Jakarta, excessive groundwater extraction has been the main culprit in its sinking.

"Houston slowed their subsidence problem down by water regulation, but they still have a big problem," says Wei.

Since 1917, parts of the city have sunk almost 10 feet (3 meters), due to the removal of groundwater. As water is pumped out of the aquifer, the fine-grained silt inside it is compressed and the land surface sinks as a result. Not much can be done once the damage is done — there's no way to fluff the silt back up as the aquifer is recharged. Decreasing groundwater withdrawals is the only way to slow down the problem.

However, it's not just water extraction that causes the land surface around Houson to lower. Oil extraction is a compounding factor, as well as the fault activity in the area.

4. Rotterdam, the Netherlands

The port city of Rotterdam in the Netherlands is sinking at a rate of around 0.6 inches (1.5 centimeters) per year, and at this point the city is already around 90 percent below sea level. Although the Dutch are famous for protecting themselves from the sea with technologies like dams, dikes, pumps and seawalls, these are only short-term fixes.

Part of the problem has to do with the country's famous windmills. For centuries the windmills have been used to drain the country's peatlands, a special kind of wetland that sequesters carbon in the form of peat-forming organic matter. Draining the peat bogs causes subsidence at a maximum rate of 3 inches (8 centimeters) per year. Combined with factors like seas that are expected to rise by 5 to 18 inches (14 to 47 centimeters) by 2050, among other factors, the future of low-lying cities such as Rotterdam is uncertain.

5. Virginia Beach, Virginia, U.S.

Virginia Beach, Virginia, at the mouth of the Chesapeake Bay, is the fastest-sinking city on the east coast of the U.S. The reasons are a combination of the tribulations of Houston mixed with the trials of New York — the already low-lying area is sinking due to overzealous groundwater extraction, mixed with the resettling of land once covered by an ancient sheet of ice. Mingled with the threat of sea level rise, scientists predict the water in Virginia Beach will rise upwards of two feet (60 centimeters) by 2050.

6. Bangkok, Thailand

Thailand's capital city of Bangkok is home to over 10 million people, but flooding is a huge problem. Situated at the mouth of the Chao Phraya River delta, Bangkok historically made concessions to the sea and the river — canals in its streets, floating markets and houses on stilts were common sights 50 years ago. But modern times have brought in the same kind of asphalt roads and high rise buildings found in any other big city in the world.

Bangkok's heavy buildings are built on highly compactable clay soil, which is one reason it's sinking — another is excessive groundwater extraction. Although sea level rise is a real danger and certainly part of Bangkok's flooding problem, a 2012 World Bank report predicts that land subsidence will be the cause of almost 70 percent of the increase in the city's flooding costs by 2050.

7. Venice, Italy

The most famous sinking city by far is Venice, Italy. Home to an intricate web of canals, Venice was built in the 5th century and has always had the Adriatic Sea, with its exceptional acqua alta high tides, to contend with. The city's founders partially knew what they were doing when they built the city on a salt marsh completely surrounded by water. What they couldn't know was that the city sits on a tectonic plate.

Venice is subsiding at the rate of 0.08 inches (0.2 centimeters) every year due to groundwater extraction while sea levels rise, and its heavy buildings have been compacting the underlying soil for centuries. But plate tectonics is also causing Venice to sink, as well as tilt slightly to the east. This means the western side of the city is higher than the eastern side.