As I sit and watch the images of terraced streets filled with brown river water, members of the armed forces rescuing people from their homes in rubber boats, and bridges and roads being torn apart by the force of flood waters, a single loud voice shouts loudly in my head: “Not this again!” It seems to be becoming a bit of a cliched turn of events during an English winter; record breaking heavy rainfall leading to widespread, damaging floods. Yet the voice inside my head is not just shouting out of a sense of resigned familiarity, it is tinged with a huge sense of frustration that we are repeatedly failing to learn the lessons of the past.
Before I can begin to explain myself, I have to deal with the misplaced accusation that has been aimed at me (and others) that this is not the right time to discuss these issues. With the people of Cumbria currently waiting for the flood waters to recede so they can rebuild their lives, some feel it is insensitive to discuss why the floods happened and what the solution should be. Some have even gone as far as to say that those raising the issues I am about to discuss in this article, are using the plight of those affected to score political points. I cannot think of a more appropriate time to discuss flooding and why it occurs. If we cannot talk about these things when they are happening, when our minds are awakened to the devastation and why we have to fix things, then when can we? I personally think it is insensitive to blindly offer our condolences to those affected and then do nothing meaningful to prevent it happening again in the future. Everything that I write in this article is said out of a desire to see these kinds of flooding events happen less often, in order to spare people and suffering.
I’m going to have to begin by going through some of the basics of why rivers flood, and how they link to the land around them. I’ll be drawing on things I first learnt during my geography lessons at secondary school, which I think illustrates how basic some of this actually is, and how shockingly naive and ignorant most people appear to be when it comes to the science of flooding. There is a woeful lack of knowledge being demonstrated in the public debate and discourse on flooding. The first thing to realise is that a river does not exist in isolation, nor is it detached from the land that it flows through. You could be forgiven for thinking this if you live in an urban area (which the majority of us now do), as your experience of a river is probably of one bounded by concrete, flowing in an unnaturally straight line through your town or city. Rivers exist within a catchment, which is the area of land that surrounds it. All of the rainfall plus the groundwater within this catchment area will eventually drain into the river. This means that changes made to the nature of the river’s catchment can have profound implications on the amount of water reaching the river. These changes can also affect the speed at which this water enters the river channel, which is another key factor that causes rivers to flood.
The second critically important thing to understand is that flooding is an entirely natural and logical thing for a river to do. Rivers are not designed or intended to hold all of the water within their catchments, nor are they capable of holding all of the rainfall during a storm event. The land either side of a river is referred to as its floodplain; the area that is covered in water when the river channel becomes full. River catchments can cover vast areas of land, and at any one time the majority of the water is often stored elsewhere, in the soil, wetlands or groundwater, not in the main river channel.
To understand why a river floods it is worth us imagining a river unaffected by humans. This river would start its life at its source, in the uplands, where other tributaries soon join it, flowing down the hillsides through mixed oak woodland, bogs and wetlands. The streams are blocked at intervals by fallen branches, forming small pools that hold back the water. As the river widens and reaches the lowland floodplain, it begins to twist and turn, meandering through a plain of wet grassland. Parts of the channel have broken off, forming ox-bow lakes where reedbeds and wetlands now occur. There is a riparian strip of trees and other vegetation on either side of the river channel, which stabilise the banks. When a storm hits and there is a large amount of rainfall, much of this is absorbed elsewhere in the catchment, and the river either does not flood, or it results in minor flooding. In the uplands, the rain is intercepted by the oak woodland and infiltrates into the soil, which slows the flow to the river and absorbs it in the ground. The tributaries have a large storage capacity due to the pools that are present from the deadwood blockages, thus releasing the water gradually into the main channel. The wet grassland and wetlands of the floodplain can take large amounts of rainfall before they become saturated, storing the rainfall on the land and releasing it gradually into the river. The meandering river channel can store more of the rainfall and the riparian vegetation helps to reduce the amount entering. It is an elegant system, a result of a natural balance between a complex network of interrelated elements.
Unfortunately, over hundreds of years, we have interfered and meddled with our river catchments and disrupted their balance. We have removed many of the natural flood defence measures that I describe above, and as a result the likelihood of our rivers flooding has increased. Here is what we have done:-
We have reshaped our river catchments, changed the way they function to suit our own ideas and structures. Our ideology is to store all of the water in the river channel, having removed the majority of the other storage options that used to exist in the uplands and on the floodplains. This is a completely unsustainable and unworkable model, a river channel can never hold all of the water within a catchment at any given time, there has to be storage options elsewhere or the river will flood, which is what happens now. We therefore have to change the way we view these floods, they are almost entirely man-made; they are our fault.
To try to combat these disasters that we have created we are forced into spending huge sums of money, both to clean up and repair the damage and to install ever bigger and supposedly better new artificial flood defences. We can see this playing out in front of our very eyes right now during the current Cumbria floods. Carlisle, one of the urban areas most affected, has a long history of flooding. In 2005 it flooded, costing roughly £250 million to clean up and rectify the damage caused. As a result of these floods, a new £38 million flood defence scheme was approved and completed in 2010. And here we are, 10 years on, £288 million spent and history is repeating itself, more rainfall, more floods, and inevitably, more money being spent. Have we learnt nothing in the intervening 10 years? Is it sustainable to keep building ever bigger and more costly flood defences, when we are predicted to have more and more bigger storms in the future due to climate change? We are already struggling to fund our current flood defence commitments, after the government has drastically cut the amount of funding available to the Environment Agency, the government department that is tasked with managing our rivers. Is it not time for a change in tactics?
We have forgotten about our river catchments and have focused too much of our time and money on our river channels, an approach which has demonstrably failed to prevent many of our recent large scale flood events. So called ‘hard’ flood defence measures (such as drains, levees and dams) have their place, but they are expensive (both in terms of installation and maintenance) and fail to address the wider problems present within our catchments. Alternative measures do exist, ones which work across the catchment, but we have ignored them for too long. We need a new strategy, one that takes a catchment-based approach to flood management, one that is based on the two basic principles of slowing the flow and increasing the storage capacity of the floodplain. With that in mind, here are a number of measures that I would recommend:-
It should be said that this approach will take time, and should be viewed as a long-term strategy to take us well into the future. The damage that we have done to our river catchments has taken place over hundreds of years, and will take decades for us to fix. Those that disagree with catchment restoration claim that it takes too long, that we don’t have time for it. Yet we spent 10 years trying to prevent Carlisle flooding again and failed, surely we can spare another 10? If we continue to throw money at cleaning up after high rainfall events, whilst failing to address the long-term restoration of our rivers and their catchments, we will continue to fail. We do have time, we are going to be living on this planet for hundreds of years to come, so we need to start fixing our malfunctioning river catchments, for our own sake and that of future generations.
One of the main reasons for writing this article was to contribute a perspective that I think is lacking from the current public debate on flooding in the UK. The public narrative following a flood in this country is worryingly predictable and terribly short on well-informed insights into why these floods happen. People firstly blame it all on the rain, oblivious to the fact that rainfall can be stored in the catchment and the reason why it is in the river so quickly is because of what we have done. It is not long before people begin calling for dredging and new flood defence spending, with no mention of alternative defence measures. Dredging is something that we appear to have a peculiar obsession with, something that we saw clearly in the response to the infamous Somerset floods of 2013/14. Dredging is expensive, labour intensive and causes environmental damage to rivers and ditches and can only make a small contribution to reducing floods, and yet public pressure forced the government to fund more of it on the Somerset Levels. The lack of basic knowledge on display is shocking, in the aftermath of the recent flooding in Cumbria, Tim Farron; leader of the Liberal Democrat party, claimed that “we need the flood plains drained“ to soak up the rainfall; I hardly think I need to point out the ludicrous nature of that claim. Environment Secretary Liz Truss said the effect of the existing flood defences was “to delay the impact and reduce the impact“ , but there was no mention of a desire to prevent the flooding or ensure the flooding took place elsewhere. Meurig Raymond; president of the National Farmers Union, in response to George Monbiot (perhaps the only journalist we have who speaks any sense on flooding) laying out some of the catchment measures that I have highlighted here, failed to address the science that supports catchment restoration. People have to understand the reasons these floods are happening and how we can prevent them, instead of being misled and supported by empty promises.
A final point I wish to make is that we also need to view our floods with a measure of humility and place them within the wider global context. In the aforementioned Somerset floods nobody died, no major urban areas were flooded and 65 square km of farmland were covered in water. Contrast this with the recent floods in Burma, where up to 100 people have died, around 1 million have been affected and 1.2 million acres of rice fields have been destroyed. Our floods pale into comparison and I sometimes think we lose sight of this in our hyped up, media driven society. This is not to say that our floods do not cause suffering, death and anguish, but just that I think it useful to place them in context.
We all need to change the way we view flooding, politicians must focus efforts on restoring the functionality of river catchments and we as members of the public have to have a more rational and informed reaction. We have to understand that rivers flood and we are going to have work out where that floodwater goes. We will have to learn to make tough decisions, letting some land flood to save others, a particularly uncomfortable problem facing many of our coastal communities. We have to understand that there is a huge man-made element in these floods, and with everything man-made there is a way to fix it. Finally, we have to change the way we view our rivers by reconnecting them with their catchments and allowing them to function how nature intended.