According to the Global Resilience Partnership, flooding has caused more “economic, social and humanitarian damage than any other natural disaster over the past 20 years”. When climate change meets urban development, it creates a perfect storm. The result? Property and infrastructure damage, widespread disruption and the risk of significant loss of life.

Why flooding really causes disruption

Major flooding in places such as Houston or Mumbai hit the headlines recently but the long-term urban planning solutions are needed to help prevent and reduce damage are far less widely discussed. The real problem is inadequate management of water when it can’t disperse from insufficient drainage and a growing non-permeable concrete landscape.

Vulnerable flooding environments

Areas vulnerable to flooding fall into two main categories:

  1. Urban expansion in areas that simply can’t support high rates of mass development. For example, busy coastal areas or reclaimed land. Mumbai is just such an example of unrestricted development in low-lying areas and reclaimed land, contributing to frequent devastating floods.
  2. Areas covered with too much impervious material and has insufficient run-off. Houston demonstrates this rise of a growing ‘urban pavement’; 25-30 parking spaces for each inhabitant.

Engineering solutions

Engineering expertise to combat the effects of flooding always starts with local hydrology and climate to develop localised, site-specific solutions. Plans include permeable materials, more mixed land use, water channels based on natural run-offs and re-using water run-off rather than dispersal. The following global examples work with these principles:

Nottingham, UK – Flood resilience

A team at the University of Nottingham are looking at the two sides of ‘urban flood resilience’ – ‘retrofit’ plans for an established city such as Newcastle plus a totally new build development in Ebbsfleet – Kent’s new garden city.

University of Nottingham

Dhaka, India – Flexible, floating accommodation

In Dhaka, an innovation from the founder of Waterstudio, a Dutch architectural practice, has created floating accommodation from shipping containers and waste plastic bottles. Easily installed and moved, especially in flood-risk areas, they work with, rather than against water movement.

New Meadowlands, USA – Slowing tidal movement

Another initiative in a low-lying habitat is Meadowlands, New Jersey, an urban area devasted by trapped tidal water after Hurricane Sandy. Now a system of berms – parallel raised banks similar to dikes – have been installed. ‘New Meadowlands’ is an integrated system working with the marshlands to slow down and control tidal movement.

Wuhan, China – Sponge cities

The world’s largest project must be China’s 16 ‘sponge’ cities such as Wuhan, a city of 10 million people in Hubei province. This huge programme is learning from water initiatives around the world based on natural materials, green spaces and waterways; bringing them together on a city-wide scale.

Wuhan, China

Engineering solutions on a massive scale

This last example in China shows the scale on which some countries are approaching the problem; looking for engineering solutions and developing supporting expertise. This perfect storm of climate change and urban development is one that many countries will have to face for decades to come.

Leave a comment below on your thoughts on creating flood-resilient urban landscapes.

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