Wetlands for Flood Protection
We've heard so far about how wetlands are good for biodiversity and also good places for a day out. Wetlands are also very good for protecting against flooding. Now that might sound like a very silly idea because surely all that water would be a problem when it comes to flood conditions but it seems that wetlands can act like a sponge, soaking up excess water. John Pygott is working for the UK Environment Agency. He's come to talk to us about the Alkborough flood defence system that he's working on where fields have been flooded to create wetlands specifically to act as flood barriers.
Helen - Thanks for coming on the show. I thought we might start by asking you to set the scene for us a little bit to describe where this area is that you're working on and what was the problem? Why did something have to be done in the first place?
John - The Alkborough project is based on the Humber estuary which is on the North sea coast of England. The problem we've got on the Humber is principally due to sea level rise. Over the past 100 years we've have about 2mm per year or so. We're faced with the situation where we've either got to raise defences higher and higher in the future or alternatively we've got to look at new ways of providing more space for increased amounts of water.
Helen - Where did the idea come from of using land that can be flooded as a way of actually counteracting this rising sea level?
John - The technique of letting water onto land out of rivers has been used quite extensively in the UK. The difference that we've got here is that this is the first time that it's been used on this scale in an estuary. The problem we've been facing is with tidal water rather than high rainfall.
Helen - One question that leaps to mind is that we're living on a very populated island here in the UK. How do you go about securing land to do something like this?
John - That's a very tricky aspect of this type of project. In order to make this work you need very large areas of land: typically in excess of a thousand acres. Those sorts of areas of land are not commonly available in many parts of the UK. We're lucky that there are substantial areas of land like that where there isn't much in terms of houses or property. It is going to be very hard to find in parts of the UK.
Helen - How do you go about making the floodwaters go where you want it to go? Is it a case of there used to be a flood wall that you've taken down or some kind of defence? I'm intrigued to know you can send the water to these areas that you're interested in.
John - It's a little bit more complicated, as you might imagine, than just taking flood banks down. These are areas of land where we've taken short stretches of flood defences away. We're directing the water in at different times with the tide. If you just take the flood defences away it has a whole series of other knock-on effects on things like navigation so it needs a lot more design and planning than just taking sections of defences away.
Helen - I take it this isn't just a case of providing an area that water can flood into, it's more that there are areas where changes are going to take place within those areas of habitat so what's going to happen when a field is turned into a wetland?
John - What we've seen on the Humber is: the site at Alkborough was flooded a year and a half ago. Already we've seen enormous amounts of sediment coming out of the river onto the old field systems. It's been really dramatic. A lot of the areas of old fields have disappeared now under quite think layers of mud. The mud attracts birds in and the Humber's very important internationally for birds. When you get this sediment you get enormous numbers of wintering wildfowl and waders coming in and feeding on these new areas of mud. It's very dramatic, particularly in winter.
Helen - So having all this wildlife is actually quite an attraction for local people. They must be quite proud of this new habitat that's been created. Is that something that you've discovered?
John - It's been fantastic. What we've seen in some of these areas, in particular Alkborough, is that people have gone from farming which I don't think was particularly profitable to starting to provide facilities for visitors. Already the area Alkborough is attracting a lot of people in for bird watching and walking and so on. A lot of local people have started to realise that there's a business to be made by providing tea rooms and car parking: all kinds of things like that.
Helen - Really it seems like quite a win-win situation. Are there any drawbacks that this kind of project can raise or is it as good as it sounds?
John - There is a drawback in the loss of agricultural land. I think there are concerns now about food security in the UK. We are talking about a permanent loss of farmland. Perhaps in the future that might not be something that's so acceptable as it is now.
Chris - Have there been any negative sentiments from people about your project because you said that the people who are interested in watching the birds find it fantastic. What about the people who've lost land or the people who have to look over the area are they worried about the future of their area? It might be flooded.
John - I think a lot of people are initially quite nervous about the idea of water from estuaries getting nearer to where they live and that's something that we've had to manage quite carefully. We've had to spend a lot of time talking to people, helping them to understand that this is for the wider benefit of the community around the estuary and they continue to be protected from the water. I think that people are nervous about seeing floodwater nearer to their houses.