Jakarta Keeps Sinking as Groundwater Use Deepens Its Flood Crisis

A City Falling Below the Water Around It

Jakarta is sinking by an average of 3.5 centimeters a year, according to assessments by Indonesia's National Research and Innovation Agency (BRIN). In the northern part of the city, the ground has dropped by as much as 4 meters over four decades, leaving roughly 40 percent of that area below sea level. For a city of about 10 million residents, the combination of falling land and rising seas puts millions of people and billions of dollars in infrastructure at growing risk.

As of January 22, 2026, Indonesia's response includes existing coastal barriers, plans for a giant seawall along Java's northern coast, restrictions on groundwater extraction and efforts to expand natural flood protection. Each addresses part of a problem that connects the water people drink, the buildings above them and the soil beneath their homes.

Yus Budiyono, a senior researcher at BRIN who has studied the sinking extensively, describes how the changing shape of northern Jakarta concentrates the danger:

Jakarta's land is sinking. The northern part is turning into a 'bowl' and a flood hot spot, vulnerable to overflowing rivers, torrential rains and encroaching seawater.

Jakarta sits on a low delta where rivers flowing from the southern highlands converge before reaching Jakarta Bay. This geography once helped carry water through the region, but human activity has disrupted those drainage systems. Heavy rain now flows from higher ground in the south toward the depression in the north, where water can become trapped rather than drain naturally.

Subsidence is the gradual sinking of the ground. In Jakarta, it makes three threats harder to manage at once: rivers overflowing, intense rainfall collecting in neighborhoods and seawater moving inland. The deeper the northern bowl becomes, the more difficult it is to move accumulated water out.

How Fast Is Jakarta Sinking?

BRIN's average of 3.5 centimeters a year masks large differences between neighborhoods. Research from IPB University found that different parts of Jakarta sank by between 1.8 and 10.7 centimeters a year during 2019 and 2020. Estimates for North Jakarta reach approximately 4.9 centimeters annually, consistently placing it among the areas with the greatest subsidence.

Other measurements describe a broader range of 1 to 15 centimeters a year across Jakarta, with some locations in North Jakarta sinking by as much as 25 centimeters annually. At that highest rate, a neighborhood can descend 2.5 meters in a decade. These local measurements and the city average describe different scales of a problem that is unevenly distributed.

Muara Baru, a district in North Jakarta, offers a visible example. An office building stands abandoned with its ground floor completely submerged, while its first floor veranda remains usable. The surrounding land sits higher, preventing floodwater from draining away. Elsewhere along the northern coast, buildings that once stood above sea level now have foundations below the water table.

Fishermen describe tides reaching approximately 5 centimeters higher each year. Some coastal households that once looked out at the sea now face concrete dykes built to hold it back. The changes can be difficult to notice from one day to the next, but their accumulation over years transforms homes, streets and entire neighborhoods.

Projections describe different geographical areas and future flood conditions. Studies indicate that, without aggressive intervention, about 25 percent of Jakarta's capital area could be submerged by 2050, with climate change potentially doubling the risk or increasing it further. Research also projects that flooding associated with subsidence could expand by 100.5 square kilometers by 2050, potentially covering 75 percent of North Jakarta.

Heri Andreas, a researcher at the Bandung Institute of Technology who has studied Jakarta's subsidence for two decades, gives a more severe projection for the north:

If we look at our models, by 2050 about 95% of North Jakarta will be submerged.

For many current residents, 2050 falls within their lifetimes. The projected changes concern the homes, businesses and coastal communities they already occupy.

Why Pumping Water Makes the Ground Fall

Groundwater extraction is the main driver of Jakarta's subsidence. The city has grown into a megacity of more than 10 million residents, with millions more entering for work each day, while the city owned water operator, PAM Jaya, has yet to provide piped water everywhere. Households and businesses fill the gap by pumping freshwater from underground.

Aquifers are underground layers that hold water. When too much water is removed, the ground above can compact and sink. The process resembles a balloon losing water and shrinking: the material that once occupied more space takes up less. In Jakarta, continued extraction combines with the pressure of the city above to push the land downward.

Residents use wells for domestic needs, while industries historically drew groundwater for their operations before government regulations curtailed the practice. The growth in registered wells shows how sharply extraction expanded alongside urban development:

• In 1879, Jakarta had 42 groundwater wells.
• By 1968, the number had risen to 352.
• By 1998, registered groundwater wells numbered 3,626, roughly ten times the 1968 total.

The strongest expansion coincided with the period when land subsidence became a recognized problem in Jakarta. The depth of a well also matters. Deep wells affect deeper geological structures and cause more substantial subsidence than shallow wells.

Hotels, shopping malls and expensive residential developments generally have the money needed to construct deep wells. Poorer urban settlements tend to depend on shallower wells, which have less effect on those deeper structures. This difference connects the physical causes of sinking to the unequal distribution of wealth and access to water.

Dependence on wells also explains why rules alone cannot resolve the problem. People and businesses still need a dependable water supply. Where piped water is unavailable or insufficient, groundwater remains the practical alternative, sustaining the pressure on aquifers even as the effects become more visible above ground.

The Weight of Jakarta's Expansion

Buildings, roads and other infrastructure add another source of pressure. Jakarta stands on young alluvial soils, sediments deposited by water that can compress under heavy loads. Research estimates that about 1.68 trillion pounds of concrete, glass and steel cover the city's landscape.

Jakarta's expansion accelerated after the 1960s. From the 1770s to the 1960s, the modern planned built area grew by only 17.7 percent. By 2014, that portion occupied 83.7 percent of the city's total area, representing growth of nearly 65.5 percent over approximately five decades. The spread of buildings and roads increased the weight pressing down on compressible ground.

Groundwater extraction and construction operate together. Removing water encourages underground layers to compact, while the built environment adds pressure from above. The result is a dual burden on soil that was already vulnerable because of its geological makeup.

Research published in Geoforum connects subsidence to patterns of urban development under the New Order regime beginning in 1965. It describes connected processes of horizontal concentration, vertical extension and differentiation: development spread across the city, extended upward and produced unequal urban spaces.

Research from 360info.org also traces the parallel rise of subsidence, groundwater wells and the modern built city since the 1960s. That expansion unfolded under President Suharto's authoritarian government, when Indonesia pursued centralized capitalist development with Jakarta at its center.

The connection gives the sinking a political dimension as well as a geological one. Decisions about where to build, which developments receive water and who can afford deep wells have shaped the pressure placed on the ground. Those decisions also help explain why the people contributing most to extraction and development are not necessarily the people facing the greatest exposure to floods.

The Cost Reaches Homes, Businesses and Public Services

Yus Budiyono estimates that flood risks cost Jakarta at least US$186 million annually. Without effective action on subsidence, projected annual losses could reach US$421 million by 2030. Using those figures, the increase would be US$235 million a year, taking the projected loss to more than twice its present level.

Flood damage consumes public money needed to repair roads, drainage and other infrastructure, diverting resources from development. Businesses lose revenue and working time when flooding interrupts operations. Households pay for damaged property, evacuation and temporary accommodation. Together, these costs weigh on economic activity and the city's attractiveness to investors.

Insurance adds another layer of financial pressure. Properties in areas exposed to subsidence may face higher premiums or become uninsurable. Falling property values and reduced investment can then leave vulnerable neighborhoods with fewer resources for maintenance, accelerating their deterioration.

Uneven sinking damages structures even between floods. Foundations and walls develop cracks, roads become uneven and require repeated repairs, and utility pipes can be exposed or damaged as the land around them moves. Fortuna Sophia, who lives in a luxurious villa in North Jakarta with a sea view, describes the repeated work needed at her home:

We just have to keep fixing it. The maintenance men say the cracks are caused by the shifting of the ground.

Fortuna says rain can bring floodwater high enough to submerge the swimming pool completely, forcing furniture to be moved to higher floors. Her experience shows how repairs and temporary adjustments become a recurring household expense while the ground continues to shift.

Health problems, interrupted schooling and the stress of living with a persistent flood threat add costs that are harder to measure. Children may be unable to reach schools, families face repeated disruption and illness can affect both quality of life and productivity. Financial estimates capture only part of that human burden.

What the Seawalls Can Do

Since 2014, Jakarta's administration and the central government have built around 20 kilometers of concrete barriers under the 46 kilometer National Capital Integrated Coastal Development project. The barriers are intended to separate vulnerable land from coastal floodwater.

President Prabowo Subianto has also announced a plan costing billions of dollars for a giant seawall extending 500 kilometers along Java's northern coast, from Banten to East Java. Its proposed reach reflects a threat extending beyond Jakarta to other communities exposed to coastal flooding.

Another initiative, the Great Garuda, combines a proposed outer seawall of 32 kilometers across Jakarta Bay with 17 artificial islands. Supported by the Dutch and South Korean governments, the approximately US$40 billion project would create an artificial lagoon. Lowering water levels inside that lagoon would allow Jakarta's rivers to drain into it, addressing river discharge as well as seawater entering the city.

Existing seawalls have helped limit seawater intrusion in Jakarta compared with unprotected places such as Demak in Central Java. Yus Budiyono nevertheless warns that barriers leave the main cause of subsidence untouched. Concrete can hold back water while the land behind it continues to descend.

Jan Jaap Brinkman, a hydrologist at the Dutch water research institute Deltares, describes seawalls as an interim measure. He estimates that Great Garuda might buy Jakarta another 20 to 30 years to deal with subsidence. That would give the city time to act, but continued sinking would eventually overwhelm the protection.

Artificial island development has also encountered public opposition. A reclamation plan for 17 islands included an arrangement shaped like an eagle, intended as a national symbol. In October 2017, Jakarta's newly elected governor at the time canceled the plan following opposition. Only three of the originally planned islands remain under development or completed.

Fishing communities could lose access to livelihoods as coastal construction changes the waters they depend on. Altered currents and sediment patterns can affect ecosystems, while large concrete structures reshape the coastal environment in ways that may bring unintended consequences. Protection from flooding therefore comes with social and environmental questions alongside engineering demands.

Green Spaces Can Share the Work

Researchers and urban planners are also considering Nature-based Solutions, known as NbS, to manage water through natural processes. Vegetation can intercept rainfall, land can store more water and planted areas can slow runoff, reducing erosion and the amount of water arriving at drains at once.

WRI Indonesia recommends combining existing gray infrastructure, such as drains and concrete barriers, with green infrastructure. This hybrid approach can extend flood management beyond rivers and into residential areas, expanding the city's ability to control runoff and prevent local flooding.

At the household or building scale, measures include biopore infiltration holes, green roofs and tanks that collect rainwater. Biopore holes allow water to soak into the ground. Green roofs retain some rainfall on planted rooftops, while collection tanks store it rather than sending all of it immediately into drainage systems.

Larger measures include multifunctional Green Open Spaces that can serve as water catchment ponds, bioswales and permeable pavement. Bioswales are planted channels that slow and filter runoff. Permeable paving allows water to pass through its surface. Both can help keep pollutants carried by rainwater out of drainage systems.

Green roofs and other vegetation also reduce urban temperatures, helping limit the urban heat island effect, in which built areas retain heat. Cooler surroundings can reduce the energy used for air conditioning. These benefits accompany flood control rather than requiring a separate purpose for every patch of green space.

Governor Instruction No. 52 of 2020 sets out interventions that include expanding the functions of green open space and developing vertical drainage, or infiltration wells. Cooperation between relevant agencies is intended to carry these approaches across Jakarta.

Mangroves provide another natural defense by calming waves. They can reduce damage from flooding associated with storm surges by more than 15 percent annually. Jakarta, however, has lost most of this protection: infrastructure development and plastic waste have destroyed 272 hectares of the 291.17 hectares of mangroves that once existed. Only the Angke mangrove ecosystem in the western part of the capital remains.

Research from IOP Science calls for managing entire watersheds and groundwater basins together. Simply sending water to sea faster, the main strategy so far, may worsen subsidence. More vegetation and structures for conserving water upstream could instead help address flooding and groundwater depletion at the same time.

Increasing infiltration and conserving water can replenish groundwater supplies while reducing flood risk. These measures can also help limit seawater intrusion and drought during dry seasons. Restoring damaged mangroves and creating green spaces offer practical steps within that wider approach.

Reliable Piped Water Is Central to a Lasting Response

Water management authorities can meet only about 40 percent of Jakarta's water demand, according to research. This measures demand supplied, while PAM Jaya's incomplete network describes the gap in piped service. Both leave households, businesses and industries dependent on groundwater.

Estimates of the population served also use different counts. Alongside descriptions of Jakarta as a city of about or more than 10 million residents, water management research gives approximately 9 million people within city limits and another 15 million commuting into the city each day. The concentration of people and economic activity places heavy demands on water infrastructure.

Yus Budiyono argues that clean water must be fully available so people have no reason to extract groundwater. Without effective action to curb subsidence, he warns, even the proposed giant seawall would provide limited protection. A dependable alternative supply is therefore central to reducing extraction.

Better water infrastructure management would also require accurate information available in real time about leaks, groundwater levels and land movement. Tracking those conditions could help authorities understand where water is being lost, where aquifers are under pressure and where sinking is accelerating.

Cities can examine their water supply chains and consider different business models for meeting household and industrial demand without excessive pumping. Options include recycling wastewater, collecting rainwater, developing desalination plants and locating water services outside affected areas.

Artificial aquifer recharge offers another approach: surface water or treated wastewater is injected underground to help restore groundwater levels. Tokyo used this method when it faced severe subsidence about 50 years ago. Japanese authorities also restricted groundwater extraction and required businesses to use reclaimed water, bringing subsidence to a halt.

Jakarta still needs alternative sources capable of replacing large volumes of groundwater. The Citarum River could potentially supply water, but it is extremely polluted. Heri Andreas estimates that cleaning rivers, dams and lakes enough to supply piped water across the city or replace deep aquifer extraction could take up to ten years.

Joko Widodo acknowledged during his presidency that cleaning Jakarta's rivers would require years of sustained work. While improvements proceed, rainwater harvesting, greater efficiency and temporary limits on extraction in the most vulnerable areas could help bridge the supply gap. The challenge is to reduce pumping while ensuring that residents and businesses can still obtain the water they need.

Who Bears the Risk, and Who Faces Restrictions?

Dr. Bosman Batubara, a research fellow at the Asia Research Institute at the National University of Singapore, links Jakarta's sinking to rapid but uneven urban development. Communities that benefited from decades of expansion tend to be less exposed to subsidence, while coastal residents face greater risks of flooding, land loss and damage to their livelihoods.

Deep wells help explain that imbalance. Commercial developments with enough capital to drill them can contribute substantial pressure to underground layers, while poorer communities using shallower wells face the consequences of a sinking coast. The distribution of harm follows differences in both wealth and location.

Dr. Bosman argues that the government's response has concentrated on visible structures such as concrete seawalls without tackling the underlying drivers of groundwater extraction and urban development. Funds flow toward protection at the surface while dependence on underground water continues.

Regulation has developed over several years, but enforcement presents a persistent challenge. The recent sequence includes both evidence of unauthorized pumping and attempts to restrict it:

• In 2017, an inspection of 80 buildings on Jalan Thamrin in Central Jakarta found that 56 had groundwater pumps and 33 were extracting water illegally.
• In 2020, Governor Instruction No. 52 outlined green space and infiltration measures to improve water management.
• In 2021, Governor Anies Baswedan issued a regulation banning groundwater extraction in nine industrial areas and along 12 roads.
• As of January 22, 2026, Governor Pramono Anung's administration reportedly plans to tighten groundwater rules further.

The Jalan Thamrin inspection illustrates the scale of the enforcement task even within a limited group of buildings. Restrictions need monitoring, while the businesses and households affected need dependable access to another supply.

Greater transparency could support that work. Public information about the number of deep wells, their depths, extraction volumes and the identities of builders or owners could help authorities and residents track groundwater use. Combined with better piped water services, such disclosure could form part of a more centralized plan for Jakarta's development.

The practical question is how to coordinate decisions that are often treated separately: construction, water supply, extraction permits, coastal protection and neighborhood development. Each affects either the pressure on the ground or the number of people and assets exposed when it sinks.

Jakarta's Warning Extends Beyond Indonesia

Jakarta belongs to a wider group of sinking cities. World Economic Forum research identifies New York, Venice and Mumbai among places experiencing urban subsidence. Groundwater use and heavy construction on vulnerable soils are recurring drivers in coastal urban centers.

A study covering 99 coastal cities found that 33 were sinking at least five times faster than sea levels were rising. That is one third of the cities examined. In parts of Asia, including Manila in the Philippines, Karachi in Pakistan and Tianjin in China, sinking rates were 10 to 20 times faster than sea level rise.

Nearly half of China's major cities are also sinking under the weight of infrastructure and because of groundwater extraction. Across affected cities, consequences include land loss, insecure water supplies, damaged infrastructure and displacement. Local geology and development patterns vary, but the pressure on homes and public services is shared.

Indonesia's decision to move its capital from Jakarta to Borneo reflects concerns about the city's environmental pressures, including subsidence. Relocation is a major response to doubts about the sustainability of the existing location, while Jakarta's residents and economic activity still require protection.

Tokyo's experience offers a practical lesson: changing water supply and restricting extraction can stop sinking. Other approaches used internationally include partnerships between public authorities and private companies to finance infrastructure, campaigns to reduce water consumption and rules governing groundwater use.

The World Economic Forum identifies five areas for action: involving communities directly, improving water infrastructure management, building partnerships between the public and private sectors, applying industry best practices and teaching water conservation. Governments, businesses, civil society and universities all have roles in that response.

For Jakarta, these lessons point back to the connection between water and urban development. Seawalls can reduce exposure to coastal flooding, green spaces can retain rainfall and mangroves can soften waves. Reducing the downward movement of the city itself requires changes to extraction, supply and the way construction and land use are managed.

Investment and regulatory commitment matter together. Tokyo's success depended on changing both water availability and water use, while Jakarta faces a potentially lengthy cleanup of replacement supplies. Reconsidering water use and infrastructure, and building resilience into urban planning, links immediate protection to the work needed below ground.

The Bottom Line

• BRIN puts Jakarta's average subsidence at 3.5 centimeters a year, with much faster sinking in some northern locations.
• Parts of northern Jakarta have fallen by as much as 4 meters in four decades, leaving roughly 40 percent of that area below sea level.
• Projections for 2050 range across different areas and flood conditions, including Heri Andreas's estimate that about 95 percent of North Jakarta could be submerged.
• Groundwater extraction is the main driver, compounded by construction on compressible alluvial soils.
• Annual losses associated with flood risks are estimated at at least US$186 million and projected to reach US$421 million by 2030 without effective action.
• Coastal defenses include barriers under a project spanning 46 kilometers, the Great Garuda proposal and a proposed seawall spanning 500 kilometers along northern Java.
• Piped water expansion, extraction controls, transparent monitoring, green spaces and mangrove restoration address different parts of the crisis.
• Tokyo's experience shows that alternative water supplies and groundwater restrictions can halt subsidence.