Floods look set to become an increasingly frequent problem so what do we do when the water starts to rise beneath our feet? Cheshire Wildlife Trust’s Katie Piercy has some suggestions.
Look into the heart of most major cities in the UK and you’ll find a watery oasis. London has its Thames, Newcastle its Tyne and Chester its Dee. Look closer at our towns and villages and most are cut through by rivers or streams. Once, rivers were our greatest economic network, bringing quick trade routes to places too far or difficult to reach by land. So invaluable were they that we even made our own, in the form of our vast canal network. The motorways of our past, our lives evolved around them, and our homes, business structures and roads began to spring up close to their banks.
Today, other means of transportation have allowed us to take a step back from our watery past and made the land easier and quicker to traverse. However, many of our cities and towns, larger and denser than ever before, still cluster along rivers. In December 2015 a series of storms caused the wettest month on record with flooding across many parts of northern England. Record rainfall in June 2016 again led to waters rising across major cities, such as York. Climate change experts predict these extreme weather events are set to become more common. So it seems the riverbank is no longer the most sensible place to make our homes. But beyond dismantling our cities and heading for the hills, what can we do to keep our feet dry in the coming years?
Rivers are designed to flood. Just as many grasslands and forests are adapted to periodically burn, rivers must burst their banks on occasion. Not only are they meant to do so but there are many things adapted to take advantage of this, from wading birds to seasonal meadow flowers.
In the past, flood defences were designed around preventing these events. Large concrete walls were erected to stop the water from making its way into our houses, banks were built up high to prevent rivers from spreading out across their floodplains and meandering bends were straightened to allow water to move more quickly through our landscape. However, time has shown that these often million pound investments can have limited effectiveness. With nowhere to go water continues to rise, and if walls are overtopped or weakened banks burst, the effects can be devastating. Even straightening our rivers only forces the problem downstream, intensifying local flooding.
But there is an alternative which is fast proving to be cheaper and more sustainable, as well as having added benefits for wildlife, tackling climate change and even improving the quality of our drinking water. Known as natural flood management techniques, they have been trialled across the UK and may herald the beginning of a new era for our rivers. Projects have been run across the country under the title of ‘Slowing the Flow’. The simple premise of natural flood prevention is to hold the water for longer within our landscape, delaying it from reaching the fast paced world of the river.
As the rain starts to fall in an unaltered natural system it may take hours or even days to make its way to the river. Some of it may fall on the hills, where peat bogs act like sponges, storing the water for long periods of time. Some of it falls on valley, or clough woodlands, where leaves intercept the water before it reaches the ground. In rough pasture, raindrops are absorbed into the soil and slowly percolate through the ground.
Once the water reaches the river, trees, bits of wood or even large rocks create barriers, slowing it down on its journey. Along the river there might be places where the water naturally overflows into reedbeds, wet woodlands or seasonal pools which can store water for extended periods of time. Finally there’s the floodplain, an area where the water can spread out while the river is high, draining away slowly when it falls.
Compare this to a landscape altered by humans. The rain falls on a tarmac road, the hard surface unable to absorb the water, it flows straight into a drain which flows directly into a river. In the uplands, peatlands have been drained reducing their ability to store water, allowing rainfall to flow down into the valleys. The same rain falls on the roofs of houses, running into gutters and down drains which lead to the river. On the edges of the river valley, trees have been felled. While some water is absorbed into the ground, much runs off the steep slopes. In winter, heavy grazing in fields has led to the ground being compacted so it absorbs little of the rainfall which runs across the surface into ditches and straight into a river. Now our river, its banks built up to separate it from its floodplain, its base scraped out and cleared of debris and its curves straightened, sends all this water downstream in one big rush. Finally it reaches a place where the brakes are applied, perhaps a sudden bend or an area where the river narrows, somewhere like your local city. Here comes the flood.
The cost of natural flood management techniques can be minimal, although some land in affected areas may have reduced yields. Something as simple as ensuring trees aren’t cleared when they fall across a river, or replanting woodlands on steep valley sides can make a big impact. We can leave natural vegetation on the banks or allow whole fields to flood when the water is high. We can restore drained peatlands in the uplands or reduce livestock density in the fields to prevent compaction of the soil. Whilst it might not seem like much, each one of these changes will slow the flow and could reduce or even prevent flooding.
One of the added benefits which come with these natural techniques is that they create homes for wildlife. Kingfishers can nest in our vegetated banks, dippers perch on our fallen trees and tawny owls live in our clough woodland. Snipe and lapwings visit flooded fields and hen harriers hunt over our peatlands.
By stopping water washing off our fields into our rivers we’re reducing the erosion of the soil our crops need to grow, and preventing pesticides and fertilisers entering our drinking water. We’re even helping fight climate change by capturing carbon in all our habitats.
Rivers are the arteries of our countryside, running from hills and mountains into seas and lakes. They are important highways for our wildlife, water sources for our crops and livestock, and areas for recreation and commerce. Without them many of our cities would never have been built, much of our trade would never have taken place and England would be a very different place.
Having given so much to us perhaps it’s time we gave these important places a little TLC. If we do this our rivers may once again become places we love to live beside, as entangled in our lives as they have been since the very start of our country’s history.
Get involved
Cheshire Wildlife Trust is launching its own ‘Slow the Flow’ project along the Dane Valley. They hope to do their bit towards flood prevention as well as improving the area for all kinds of wildlife.
For more information or to get involved, contact kpiercy@cheshirewt.org.uk.
