When the City Floods Below: Subways Drowning Under Climate Change
The year 1863 marked both the start of the London Underground (subways) and the reign of Queen Victoria. At that time, the Underground served as a symbol of a modernizing London. It was able to solve the rising congestion challenges in the city and provided shelter from the harsh English weather, and ultimately served as a shelter during the Blitz saving numerous lives. In contrast to then, a London Underground that is modernized is in dire need of updates, and is in terrible condition. About 60% of the network is not air conditioned, and therefore the stations and tunnels transform into sweat boxes that pose a health risk on extremely hot summer days. The systems that were once created to make life in the city more manageable now have to deal with the challenges of climate change and the increasing frequency of extreme weather in their attempts to make life in the city more manageable.
Global Subway Vulnerabilities: From London to New York
Like the London Underground, the New York City subway faces parallel challenges, having first opened in 1904. Now, the subway is an intricate web of vulnerability. During intensifying rainstorms, stairwells and platform vents become gushing waterfalls, and the city’s oldest stations, some built below the water table, suffer the most. With every extreme weather event, the subway reveals its outdated pumps and poorly placed grates, exposing its decades of neglected maintenance. This systemic problem of aged infrastructure is not unique to New York, as subway transit systems across the globe neglected modernization in the face of evolving weather and urban rhythms.
Floods, Heat, and the Limits of 20th-Century Design
These extremes were revealed most vividly in 2021 Zheng-Zhou, China, where 8 inches of rain fell in one hour. Subway cars filled with water and became coffins for panicking families. Fourteen lives were lost to what should have been a safe, modern transit system. This serves as a reminder that new infrastructure does not guarantee safety in a world shaped by climate change. Other cities—Tokyo, Paris, London, New York—are facing similar ‘rain bombs,’ as Eric Wilson, Vice President of Climate Resilience and Sustainability Planning at MTA, calls them. “Each storm presents a different challenge, revealing new problems in new places,” Wilson argues. This demonstrates that even the most sophisticated metro systems in the world are only as safe and protected as the environmental assumptions were based on.
Engineering Solutions for Extreme Conditions
The subway system in New York faces additional challenges because of its location. The subway pumps 13-14 million gallons of water every day to prevent flooding and seepage. This amount increases many times over during heavy rainfall. Some of the pumps are over 60 years old, which shows how badly investment is needed. Modernizing the water removal equipment is included in the capital budgets, but cities are also trying to pursue less direct approaches. To help prevent flash flooding, the subway entrances are being raised and are also being outfitted with steel benches disguised as protective barriers, and new drainage systems. A good example of this is where the G train station in Brooklyn has the riders going up 2 steps before going down which helps with the ever increasing stormwater levels.
Heat Challenges in London
London faces a different, but equally pressing, threat: Overheating. The combination of its clay geology, deep tunnels, and limited air-conditioning creates stifling conditions in the summer. Additionally, only 40% of the Underground has full air-conditioning, and deeper lines will remain largely uncooled due to structural and ventilation limitations. Lilli Matson, Chief Officer for Safety, Health, and Environment at Transport for London, explains: “Air conditioning on deeper lines is a real challenge. We are using novel methods, like fans and super fans, to reduce heat, but some solutions are inherently limited by the network’s age and design.”
Integrating Urban Design with Climate Resilience
Urban design has been paired with engineering, forcing innovation. In Manhattan, the legacy of Superstorm Sandy in 2012 caused the construction of tunnels that could be sealed with inflatable plugs to protect them from storm surges. While useful for anticipating hurricanes, these systems are less helpful for sudden, intense rainfall, prompting the need for responsive solutions. Similarly, New York has decided to combine traditional engineering with environment-friendly alternatives: curbs, raised grates, and permeable pavements that reduce runoff are coupled with surface-level stormwater capture before it enters the subway system. The project at Green-Wood Cemetery in Brooklyn showcases this kind of work. As the city’s largest private landowner, the cemetery worked with The Nature Conservancy to replace blacktop with permeable paving stones, install underground water storage, and manage runoff at Sylvan Pond. These actions help mitigate over 55 million gallons of stormwater from overwhelming the combined sewer system each year. Joe Charap, Vice President of Horticulture at Green-Wood, points out that “Despite being private, we are part of the community. Changes we make here can significantly reduce the city’s stormwater burden.” Visit The Climate Post for more insights.
Climate Policy and Urban Infrastructure
The combined stormwater management and green construction techniques also advance another method that ensures the protection of subways and the integration of the city’s ecosystems: “Thinking further above and below the ground.” It includes parks, planting more trees, sustainable urban drainage systems, and the use of permeable surfaces that help reduce the risk of flooding, and therefore help mitigate the urban heat island effects which worsen temperatures in the underground infrastructures. Matson makes sure to point out: “Making the city itself greener and more resilient to heat helps the transport network function more reliably.”
Challenges of Urbanization and Climate Change
City environments utilize two-thirds of the area for roofs, cement, and asphalt, which reduces the natural absorption of rainfall and increases retention of heat. Bill Ulfelder, the executive director of the New York chapter of the Nature Conservancy, emphasizes, “Ninety percent of cities and suburbs is privately owned. We must rethink how we manage these spaces to improve urban resilience.”
The impact goes far beyond merely comfort and convenience. Increased heat combined with flooding puts a strain on the public’s welfare, safety, and overall productivity. Commuters in overheated or flooded stations become susceptible to dehydration, injury, or even death. This causes ancillary delays which ultimately impact the entire urban economy, including businesses, schools, and emergency services. On top of everything, the transit agencies face increasing operating costs as they retrofit, replace gear, and design emergency plans for their infrastructure. In a nutshell, climate change is turning subways, previously dependable lifelines, into intricate challenges of risk management.
Proactive Solutions and Global Lessons
As metropolitan areas of the world are catching up with the new realities posed by recent changes in climatic conditions, we see Tokyo where one of the world’s most advanced and on-time metropolitan railways and Shinkansen trains invest heavily in water pumps, floodgates, and emergency drainage systems. Furthermore, Paris has also decided to incorporate climate adaptability with regards to planned extensions to include flood barriers and elevated entrances. Even in newer systems like Singapore and Hong Kong, extreme rainfall and heat are accepted in construction plans as default conditions.
However, London and New York experience high costs and slow production due to the need to adapt modern systems to older, legacy ones. Options are few because of deep tunnels, historical structures, and dense urban populations. As a result, these authorities are increasingly focusing on complementary strategies:
- Urban Greening: Street trees, green roofs, and parks lower the runoff as well as lower ambient temperatures.
- Permeable Pavements: Materials that can soak up water will lessen the burden on drainage systems.
- Community Partnerships: Works with private land owners, for example, with cemeteries and universities, that detain the runoff before it floods the public systems.
- Smart Pumping and Sensing: Operators respond to flood risk in real-time, optimizing the use of pumps and preventing floods through real-time monitoring.
- Public Awareness and Planning: Pre-educating and commuting, as well as climate risk, alongside public transport services planning, helps effectiveness.
The Human and Social Dimension
Social equity is another important factor: the public and lower-income communities tend to rely on these services, and during service interruptions, they have limited options. These systems are not only an infrastructure priority; it is an act of social justice.
Construction and infrastructure work on one section of a city’s transport network often leads to slow, slushy traffic in other regions. For instance, the hot, deep underground train and subway lines in London can be said to be a kind of torture, increasing the chance of heat stroke. New York is often hit by heavy rains, leading to temporary flooding of certain areas of the city, areas showing chronic symptoms often featuring heavy aging infrastructure or bit crumbling subway stations. These human impacts combined create and fuel the political anger people feel these days leading to increased demand in services to these transport and public service agencies.
Urban Transit’s Future Challenges and Adaptive Design
The issues that await a solution for urban transportation systems are overwhelming and can lead to a loss in productivity. Per subway systems, city planners and engineers are automatically coming up with integrated systems designs to streamline planning, management, and control as a cohesive unit. Some of the more popular suggestions made so far are rethinking street sculptures, greening to other modern standards, rehabilitation of subway systems, and safeguarding equipment and systems for climate disasters. All these concepts are directed towards shifting subway systems from a responsive reactive mode to a more adaptive approach network with the capabilities of overcoming climate-induced disasters like floods and wildfires.
This achieves the metaphor of a subway system that was once a symbol of modern innovation in an economy. Adapting subway systems to disasters will lead to a loss of innovation and puts a marker on the need of economic restoration. Doing this will mark the loss of innovation for a modern society.
Final Thoughts: A 21st Century Subway
Originally, subway systems were designed to serve 19th and 20th century cities, but now they have to accommodate the pressures of rapid climate change. From the Tube in London, which gets unbearably hot, to subway stations in New York that are prone to flooding, it’s clear that climate change is rewriting the rules of urban transit. There are solutions, but they require vision, funding, and community engagement. If cities are able to tackle these problems, the subways will still have the ability to serve and transport millions. Furthermore, they will showcase urban resilience and demonstrate how infrastructure can adapt to the challenges of a hotter, wetter, and more unpredictable planet.
To summarize, today’s subways, and urban infrastructure at large, were not built to accommodate the climate challenges we are currently facing. How we adapt to the situation will define if urban areas will thrive in the coming century.
