Floodable parks, resilient infrastructure to cope with surging rainfall in cities

When extreme weather phenomena grip our cities, floodable parks can act as resilient infrastructure, combining beauty with functionality

Bangkok is pioneering in the fight against flooding. Rapid urban development covered much of its wetlands and parks with concrete, drastically affecting the way in which water flowed through the city when torrential rain fell.

But now, instead of building walls and draining floods into the rivers beneath the city, Bangkok is creating a system of floodable parks. Take Centenary Park, an extraordinary example of how urban design can achieve harmony with nature, converting water into a reusable resource.

This green lung in the heart of Bangkok is not only a refuge for biodiversity and an oasis for people living in or visiting the city, it also acts as a gigantic sponge, able to retain millions of liters of water during storms. Bangkok is showing the world that it’s best not to fight against water, but live with it. And more cities everywhere are increasingly learning from Bangkok’s experience.

What will I learn from this article?

What is a floodable park?

Floodable parks are green areas designed to fulfil a double function: recreational spaces on the one hand, while at the same time acting as natural infrastructure able to manage rainwater during flooding events.

The concept might appear contradictory at first. A park that allows itself to flood? But this is where its genius lies. On sunny days, such parks function like any other urban green space, with walkways, playgrounds and gardens. But when torrential rains arrive and overwhelm the rivers, the special design of these parks swings into action. They work like giant sponges that retain and store huge volumes of water temporarily to avoid inundating streets and homes. Once the danger has passed, the accumulated water can be filtered, reused and slowly drained into collection systems.

“The parks work as giant sponges that retain and store huge volumes of water”

Origin and evolution of floodable parks

Floodable parks were borne out of a specific, urgent need to adapt cities to the natural cycles of water and mitigate flood risks. Although the concept might appear to be new, its roots lie in the human capacity to coexist with nature, using what nature offers without altering its equilibrium.

If we look back, the first initiatives to manage water in urban environments were based on traditional solutions like canals, dams and drainage systems. With the growth of cities in the 19^th and 20^th Centuries, however, these methods proved insufficient against torrential rain, river flooding and the rise in extreme phenomena linked to climate change. As a result, engineers began to imagine how they could combine resilient infrastructure with nature, opening the way to what we now know as floodable parks.

Asia was one of the first continents to understand the potential of such “living” infrastructure. An iconic example is Qunli Park, China, which has been designed to regenerate urban wetlands and manage rainfall. In Europe, countries like the Netherlands, with its long history of living with nature, has led this transformation with projects such as Room for the River. In Latin America, Victor Jara Park in Santiago de Chile, still under development, will be one of the largest and most ambitious floodable parks yet.

Why are they important?

In a world where cities are expanding at a vertiginous rate and extreme weather phenomena are increasing, floodable parks have become key to creating more resilient, flexible and sustainable conurbations.

Smart management of floods

The main function is to protect cities from flooding, an increasingly frequent problem in densely-built towns and cities. Floodable parks capture and store rainwater during intense storms, avoiding flooded streets and filthy water that ends up polluting rivers and seas.

Adaptation to urban climate change

Floodable parks are also a strategic solution to global warming. They help regulate local temperatures, combating the heat island effect by integrating large park areas in cities. They also balance water cycles by allowing the water to filter into the ground or be used for irrigation, reducing the pressure on water resources.

Spaces for improving the well-being of communities

Far from being limited to absorbing water, floodable parks are also a refuge for the well-being of the city’s inhabitants. Once the rain has stopped, these spaces recover their use as recreational zones, offering areas for strolling, playing sport or relaxing while surrounded by nature.

Safeguarding biodiversity

The parks are genuinely urban oases for flora and fauna. Their design includes vegetation which not only resists floods, but also creates habitats for local birds, insects and plants. By serving as wetlands, they support essential ecological processes and promote biodiversity in environments where concrete and asphalt no longer dominate.

Designing a floodable park, a technical and sustainable art form

Selection and analysis of the landscape: such spaces should be located in areas with a tendency for flooding due to their low altitude and nearness to rivers and river basins. Once the land has been selected, geological, climatic and water studies are carried out to understand how the water flows in the area and the land’s absorption capacity.
Hydraulic design: once the context has been established, it is decided how the park will manage water. This involves planning storage and drainage systems, including tanks and underground deposits capable of retaining large volumes of water during intense rainfall. These systems are connected to rainwater networks and sewage systems to ensure control over the water cycle. They also incorporate safe outfalls which regulate the gradual liberation or reuse of captured water.
Integration of resilient plant-life: vegetation facilitates the filtering of water to the ground, contributing to reducing pollution and creating habitats for local fauna, fostering biodiversity and connecting residents to nature.
Incorporation of recreational areas: functional areas such as paths, sports fields, viewing points and children’s playgrounds should also be designed into the parks. Such elements transform the park into a technical project to build a living, attractive, community space, adaptable to the season or climate.
Sustainability commitment: this involves using recyclable materials wherever possible and renewable energies for lighting and pumping systems, and guaranteeing a minimum environmental impact during construction.

To conclude, floodable parks are an innovative, multifunctional solution in the face of urban and climate challenges. They can marry sustainable water management with the creation of ecological and recreational spaces to transform our cities. Adopting this kind of resilient infrastructure does not only mitigate risks, but also improves the quality of life, fosters biodiversity and invites us to rethink our connection to nature.

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