Can we learn to live with floods?

It's predicted that climate-driven extreme weather events, such as flooding, are going to become more common and more severe around the globe. The big question is what can we do about it? How are we going to protect ourselves into the future? Dr Ilan Kelman, a researcher for Risk and Disaster Reduction at the Institute for Global Health at UCL, spoke to Kat Arney about how we can reduce the risk...

IIan - The first thing that we can do is actually learn from our past.  So, flooding has always happened and humans have been dealing with it for 10,000 years, sometimes better, sometimes worse.  So, let's look at what went wrong, what went right, and try and implement that.  We can do that at the very small level, at the household level, so people can make decisions in their open properties to use flood resistant finishes, flood resistant materials.  But there's much wider issues in terms of planning, urban governance, dealing with people's streets, houses, infrastructures, and that means planning, living with rivers, living with coasts.  A flood plain is called that for a reason...

Kat - That's the bit that floods?

IIlan - That's the bit that floods.  It has a job to do, so maybe we should think about the way we live, how we live, where we live, and let the flood plain do its job.

Kat - So where are some parts of the world that are doing this well, that are coping with flooding and flood plains?

IIan - Well, I grew up in Toronto, Canada and I always enjoyed the ravine system which was wonderful recreational pathways, wildlife, cycling, walking.  Then when I got into this as a profession I realised, in fact, it came from flooding.  So 1954, a devastating hurricane went through Toronto - Hurricane Hazel.  It killed about 83 people and, in response, the government said "well, we're going to let the ravines, the rivers be flood plains, which is what they are meant to be being beside a river."  So they designated it to be green areas, greenways, recreational pathways and building is now forbidden there.

Kat - Now, as the global population does increase though, building is encroaching on flood plains.  I've lived in East London which is basically a swamp and they are building all kinds of things right next to the river.  And is this risky, not just in London but in other parts of the world?  Should we just not be building there at all?  Can it be possible to build safely in these areas?

IIan - Wherever we build there is going to be some risks.  Therefore, we have to ensure that we have the knowledge and work with the people in the areas to determine what risks they do want; what risks they don't want.  If we avoided all flood plains in all of the risky areas we wouldn't be able to build anywhere.  That's where we decide - well maybe at the local level, maybe at the household level.  What we have to do is accept that some houses, some buildings are going to be flooded at times but, construct them in such a way that it's easy to wash them out, clean them afterwards and then go back and live there.

Kat - And presumably tell people to store stuff in waterproof boxes?

IIan - Well, part of it is ensuring there are not valuables on the ground floor; part of it ensuring we do have an adequate warning system; part of it is people knowing they are in the flood plain and therefore being able to respond and react when warnings are issued.

Kat - Tell me a bit more about some of the kinds of strategies that we can use to enable us to build on flood plains because, for example, just building urbanisation increases the risk of flooding.  Are there ways, for example, planning or housing could help to mitigate some of those risks.

IIan - This is a lot of the challenge that people do need a place to live, we do need the infrastructure.  As soon as you pave something over that increases run off but there are ways to reduce that so we can use, for example porous material on the roads.  That means it will rain on the road and go straight through, rather than necessarily giving driveways, rather than necessarily paving over front gardens.  It would be possible to keep them as plants.  And also, a lot of it is simply the layout and the planning to ensure that when it does rain the water does go into the river, and that the river has a capacity to take that water rather than bursting it's banks.

Kat - Is there a risk of kind of over-engineering this?  How often would these kind of events happen?  Would it make it worth it in financial terms to build all this kind of stuff in?

IIan - Well, certainly at the moment in places in the UK, we are over-engineering anyway and a lot of the over-engineering is an attempt to separate people from the water.  That makes a lot of sense, no-one wants to be flooded.  It does keep us dry.  On the other hand then, when it does rain and as the rainfall patterns change, when flooding happens it seems unusual - people are not ready for it.  So, what we have to do is actually work with people, and ourselves to try and determine what balance are we seeking.  How often will we accept being flooded or do we want to completely separate ourselves from the water, recognising that maybe every 50 years, maybe every 100 years, there's going to be a massive flood.  There's no quick fix, there's not silver bullet.  We simply need to recognise there's a whole variety of solutions we can take and it really depends on how much we are going to accept being flooded, to what degree, and how frequently.

Kat - And we've just heard from Claire earlier about the vulnerability of developing countries that are poorer.  How can they cope with these kinds of risks?

IIan - Everyone, whether they are in Myanmar as Claire mentioned, whether they are in East London where you live, everyone has some form of knowledge but, they also have gaps in their knowledge.  That's where it's not about going in and bestowing our wonderful aid and wonderful ideas on these poor people, it's actually about ensuring we work with the people, we use their knowledge, recognise what they don't know and work together to avoid the risk of flooding.