Sinking Cities: How Groundwater Depletion Drives Land Subsidence in Jakarta and Ho Chi Minh
Groundwater over-extraction for domestic and industrial use is causing Jakarta and Ho Chi Minh City to sink rapidly. This article investigates the environmental, social, and economic impacts of land subsidence threatening these megacities' futures.
Jakarta and Ho Chi Minh City, two of Southeast Asia’s most dynamic urban centers, are facing a critical and often overlooked environmental crisis: land subsidence caused by excessive groundwater extraction. While these cities power economic growth for millions, their foundations are literally sinking, posing severe risks to their populations, infrastructure, and long-term sustainability.
The Roots of the Crisis
At the heart of the problem is groundwater depletion. Both Jakarta, Indonesia, and Ho Chi Minh City, Vietnam, rely heavily on underground water sources to meet the soaring demands of their growing urban populations and industries. Surface water supplies are often inadequate or contaminated, and municipal water infrastructure struggles to keep pace with expansion. As a result, residents and businesses turn to groundwater wells, frequently drawing beyond sustainable limits.
In Jakarta, the dependence on groundwater is staggering: it is estimated that nearly 60% of the city’s water needs are met by wells dug into aquifers beneath the city. In Ho Chi Minh City, although the city has improved its water supply network in recent years, over a third of the population still relies on groundwater wells, especially in peri-urban and industrial zones.
Excessive pumping lowers the water table, causing the soil, particularly soft sediment and clay layers beneath the cities, to compact irreversibly. This results in land subsidence—the gradual sinking of the ground surface. Jakarta experiences some of the highest rates globally, with certain districts sinking as much as 10 to 20 centimeters annually. Ho Chi Minh City has similarly alarming average rates of 2 to 5 centimeters per year, with hotspots exhibiting even faster subsidence.
Consequences of Sinking
The cumulative effects of land subsidence exacerbate numerous vulnerabilities. Infrastructure such as roads, bridges, and buildings are increasingly prone to damage and collapse. Flood defenses and drainage systems become less effective, increasing flooding risks during seasonal rains and tropical storms. In Jakarta, sinking land combined with rising sea levels threatens to submerge significant portions of the city in coming decades. The northern coastal areas are particularly at risk, with some studies warning that parts of the metropolitan region could be underwater by 2050 if current trends continue unchecked.
Ho Chi Minh City faces a similar fate. As the Mekong Delta experiences decreasing sediment supply due to upstream damming and accelerated coastal erosion, the land subsidence intensifies flood susceptibility in the city. Floodwaters can infiltrate deeper, affecting residential communities and economic hubs, disrupting lives and livelihoods.
Moreover, the economic cost is mounting. Repair and maintenance of subsided infrastructure impose heavy financial burdens on city governments. Jakarta already invests substantial sums each year to stabilize critical areas, while businesses and residents shoulder additional indirect losses due to disruptions and damages.
Responses and Challenges
Efforts to address groundwater depletion and land subsidence have been initiated but face complex challenges. Jakarta has developed a multi-pronged strategy, including expanding piped water access to reduce well dependence, regulating groundwater extraction through licensing, and constructing giant sea walls as part of the controversial National Capital Integrated Coastal Development project. However, enforcement remains uneven, and illegal wells continue operating in many neighborhoods.
Ho Chi Minh City has prioritized upgrading its water supply systems, aiming to ensure universal clean water access by 2030. Regulations on industrial groundwater use have been tightened, and pilot projects to recharge depleted aquifers are underway. Still, the rapid urban expansion driven by population growth and industrialization complicates control measures.
Public awareness and community involvement are also crucial. Many residents remain unaware of the long-term dangers of drawing groundwater or lack affordable alternatives. Coordinated efforts between government agencies, urban planners, and civil society are vital to implement sustainable water management and land use practices.
Looking Forward
The sinking of Jakarta and Ho Chi Minh City illuminates urgent lessons for other rapidly urbanizing coastal mega-cities worldwide. Sustainable water governance, investment in infrastructure modernization, and adaptation to climate-induced sea level rise must be pursued in tandem. Crucially, integrating scientific research, such as satellite-based subsidence monitoring and groundwater modeling, into policymaking can guide targeted interventions efficiently.
The clock is ticking. Without accelerated and collaborative action, the economic engines of Indonesia and Vietnam risk stalling beneath rising tidewater and collapsing foundations. Jakarta and Ho Chi Minh City can yet transform their sinking crises into opportunities for resilient, equitable urban futures—if the imperative to safeguard their ground beneath their feet is met decisively today.
The article first appeared in Business News Magazine.
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Johan Chairil