The global surge in urban flooding presents an escalating challenge that has captured the attention of city administrators and urban planners worldwide. This phenomenon, characterised by its complexity and urgency, has particularly taken centre stage in India. Over recent years, the country has witnessed a distressing surge in urban flood disasters, with major cities bearing the brunt. In the current year, 2023, urban flooding has once again made headlines, affecting areas such as New Delhi, Bengaluru, and Gurugram. Each monsoon season highlights the ongoing problem of urban flooding in Indian cities, exacerbated by the overarching threat of the climate crisis.
Different from other types of floods, urban flooding is when heavy rain causes immediate, localised, and sudden flooding in cities. Unlike rivers that rise slowly, urban flooding happens swiftly, often in areas that do not usually flood. An essential factor contributing to this phenomenon is the rapid urbanisation and its consequences. More concrete and less green space mean rainwater cannot soak into the ground as easily. This leads to much higher flood levels, sometimes 1.8 to 8 times higher. This intricate interplay of urban development, climatic patterns, and their profound impact underscores the urgency of a comprehensive approach to tackle urban flooding — a strategy that encompasses infrastructural enhancements and forward-thinking policy implementations.
Reasons behind flooding in urban cities
Urban flooding is a global problem that plagues cities across the world, and while each city faces its unique set of challenges, a common factor that unites them is the issue of inadequate urban planning and governance.
One of the significant contributors to urban flooding is the absence of proper stormwater drainage systems in many localities. Existing drainage systems often suffer from poor maintenance, leading to clogging with debris and mud. The excessive concreting of open spaces diminishes their permeability, hindering the absorption of rainwater into the ground. Additionally, the uncontrolled expansion and densification of cities strains the capacity of existing infrastructure.
As cities expand to accommodate their growing populations, there is an increasing demand for construction, such as housing, schools, hospitals, and more. While natural factors like river overflow contribute to flooding, human activities significantly exacerbate the problem. Unregulated construction, especially on reclaimed wetlands, floodplains, and low-lying areas, poses a substantial risk. Urbanisation has led to the loss of vital wetlands, which play a critical role in flood mitigation by absorbing water and slowing down floodwater. According to a report by the NGO Wetlands International South Asia, Indian cities have lost 25 hectares of wetland for every 1 square kilometre increase in built-up area over the past four decades. As per World Wildlife Fund, India has lost 50 % of its wetlands in the last 100 years. Wetlands are important since they act as nutrient traps, enriching floodplains’ fertility. The hasty pace of urbanisation often disregards the natural topography of an area, making urban floods more of a man-made disaster.
The problem of urban flooding is a multifaceted challenge that results from a combination of factors specific to each city. However, at the heart of the issue lies inadequate urban planning and governance, which leads to the overdevelopment of cities without consideration for natural ecosystems and flood mitigation measures. Balancing urbanisation with environmental preservation is essential to combat the growing threat of urban flooding.
The need for sustainable urban development
In conclusion, the urban landscape worldwide is undergoing significant transformations, marked by high population densities, vulnerable migrant communities, and an alarming increase in urban flooding incidents. This phenomenon presents an immense challenge to city administrations and urban planners globally.
The impact of urban flooding extends beyond property damage, as it also leads to the mixing of sewage and floodwater, resulting in adverse health consequences. The economic activities thriving in urban centres further exacerbate the consequences of flooding. India, in particular, has been grappling with recurrent flooding, with this year’s floods being particularly severe due to the compounding factors of poor urban planning and the climate crisis.
The costs of urban flooding are very high, not just in terms of property damage but also the serious impact on people’s lives, especially in vulnerable communities. To address this crisis, building flood-resilient infrastructure is an urgent necessity. Moreover, the establishment of a robust early warning system, as advocated by experts and meteorological authorities, can significantly enhance preparedness and mitigate the impact of urban flooding.
It is essential for urban planning and governance to keep pace with changing weather patterns and the rapid urbanisation India is experiencing, as cities struggle to accommodate a growing population while meeting their infrastructural demands. Looking ahead, a comprehensive approach that combines improved forecasting, flood-resilient infrastructure, and sustainable urban development is imperative to ensure the safety and well-being of urban populations worldwide.