Cheshire Wildlife Trust - Five things we must do to prevent future floods
PUBLISHED: 00:00 18 April 2014
As the country slowly recovers from a winter of extreme weather, Tom Marshall from Cheshire Wildlife Trust wonders if we’ve pushed our natural environment too far in the battle to stop flooding
For several weeks earlier this year, large parts of Britain’s south west, Thames Valley and Midlands lay underwater, at the mercy of a relentless period of low pressure weather systems that saw river records broken and groundwater levels at their highest for a century.
From the rural Somerset Levels, to the outskirts of London and the centre of Worcester, several feet of floodwater brought misery to thousands and generated an often heated and personal political debate that pitched ministers against government environment departments operating on recently reduced budgets. As the issue of relief funding and on-the-ground support took centre stage in the media, the wider science behind what led to the floods was often overlooked.
But with an ensuing political storm to rival those that caused the widespread damage, should we now be looking to nature for the solution, rather than battling against it?
Since World War Two, our urban and rural landscape has altered radically. Fewer hedgerows, degraded habitats and more intensive farming mean our countryside is far less able to store water now than it could 100 years ago. Historically, natural ‘sponges’ in the landscape like peat bogs, reedbeds, broadleaved woodlands, wetlands and species-rich grasslands would have made an effective difference to the level and intensity of water hitting our river systems.
In other places, a greater volume of water is now reaching the floodplain more quickly because of the loss of natural habitats, replaced with efficient agricultural drainage systems that have been constructed over many years. In some areas, farming practices can also lead to vast quantities of soil being washed off the land into watercourses and the sea. Although the effect of dredging sat high on the political agenda in Somerset, it remains just one part of the wider issue of how we manage run-off and flow capacity.
Perhaps surprisingly, the issue of flooding in our urban areas can owe more to what happens further upstream, long before high streets and road networks fall victim to rising waters. Upland sponges like peat bogs can do much to help those living further down the river – all the more reason to ensure these habitats are maintained in the healthiest possible condition.
Another well-publicised impact that has exacerbated urban flooding is the development of our floodplains. This increased coverage of impermeable surfaces over areas that would traditionally be ‘sacrificial’ during flood events, means that large volumes of water that would have otherwise been stored before being allowed to flow into the river at a reduced pace are now entering the system almost immediately. Even small changes like the loss of gardens in favour of driveways as car ownership has increased have also had a cumulative effect.
Ultimately, a sustainable water cycle within our countryside benefits all of us; ensuring we have a healthy water supply when we need it, habitats where wildlife can thrive and communities can engage with nature, and rivers and that are able to cope with the extremes of climate change and extreme weather.
By working with nature, rather than against it, we can find solutions that may help to alleviate the impact of extreme flooding events:
In partnership with the Environment Agency, at our Hockenhull Platts nature reserve near Waverton an overspill sluice allows water from the River Gowy to flow into newly created wetlands during times of flood that follow the original, more meandering course of the river. In doing so, a proportion of water can be stored in this rural location away from properties and farmland, and this in turn helps to introduce fresh water into the wetlands which act as feeding and refuge areas for otters and water voles, along with breeding amphibians and dragonflies during the summer months.
At our largest nature reserve, the 165 hectare Gowy Meadows near Ellesmere Port, floodplain grazing marshes are managed in partnership with Essar (formerly Shell) for a wide range of farmland birds. In times of flood, these marshes can be allowed to accept large quantities of water to limit the effects on industry to the north including the Stanlow Refinery. This periodical flooding allows water into scrapes and wetlands that host hundreds of wildflowl over winter, and birds like snipe and lapwing during the summer.
The terminology of flooding explained
Groundwater: water sitting in ‘aquifers’ and other underground natural stores. When this reaches full capacity and ground is saturated, new rainfall has nowhere else to go.
Flood plain: typically large, flat areas adjacent to rivers. Often very fertile as a result of silt and nutrients previously deposited there by overspilled floodwaters.
Run-off: the process of water leaving hard surfaces or saturated soft surfaces and entering into rivers, ditches and streams either directly or via drains.
Green-roofs: grass, succulents or wildflowers are grown in top of standard roof coverings, helping to both store and slow-down the speed at which run-off enters drainage systems.
Peat bog: found both in uplands and sometimes lowland areas, these are habitats dominated by sphagnum, a plant capable of storing many times its dry weight in water.
A Living Landscape: the Wildlife Trusts’ strategy for landscape-scale management of our countryside, putting traditional methods of looking after land next to natural corridors like rivers at the heart of creating space for nature.
A five point plan
The Wildlife Trusts’ proposals for tackling flood management
1. Fix our broken ecosystems
We need to restore our natural habitat ‘sponges’ across the whole landscapes to make them more robust and able to retain water and reduce surface run-off. This could be achieved by making payments to farmers linked to measures that will protect these valuable habitats. National strategies must also move away from a focus on dredging and unsustainable land drainage.
2. Take an integrated approach
Current flood-risk management is too fragmented and too heavily focussed on the old ways of managing the problem, which can have negative impacts elsewhere. The restoration of nature must be at the heart of this approach if it is to work. The authorities and agencies responsible for managing flood and coastal erosion risks should prioritise natural and sustainable solutions in rural and urban areas, and along our coasts.
3. Stop development on floodplains
Planning policy must rigorously prevail against urban floodplain development. Where local authorities see no alternative, priority must be given to minimising impact through techniques like sustainable urban drainage systems, green roofs and integrating nature reserves as flood alleviation.
4. Give flood agencies the resources needed
Positive action can only be achieved by funding appropriate levels of resources and staffing within the Environment Agency and Natural England. The Treasury needs to recognise that the economic benefits provided by these government agencies working at their full potential far outweigh the enormous costs of flood damage, severe drought and the hidden costs of species decline.
5. We can all do our bit
Create a green roof – whether on our home or on top of the garden shed – planted roofs help to slow the flow of water run-off in bad weather and helps stop flooding. Consider reverting paved areas of your garden back to greenspace or creating wetland habitats in our gardens - whether it’s a pond or beautiful bog garden, these habitats all help absorb water and are wonderful for wildlife.
See a Living Landscape in action at the Wildlife Trust’s nature reserves along the River Gowy. Find out more at www.cheshirewildlifetrust.org.uk