How nature’s wetlands
can protect us
Flooding
How nature’s wetlands can protect us
As millions around the world find themselves living with an increased risk of flooding, and with man-made defences no longer proving enough, there’s a pressing need to find new solutions.
It might seem counterintuitive, but adding water in the right places could be the answer.
Rising floodwaters
For local resident Bryony Sadler, it was torturous having to watch the waters creep relentlessly across the Somerset Levels, coming ever closer to her home, while being helpless in the face of their advance.
‘There was two foot of water throughout the whole house and for three weeks, just to be able to get home to check the house you had to wear waders because you were literally pushing up to your thighs in water to get to your house.’
It was a position she never thought she’d find herself in. In January 2014, after weeks of intense rain, floodwaters in Somerset reached record levels, affecting houses previously safe from flooding. The flood wrecked Bryony’s kitchen, damaged carpets and floor coverings, warped doors and skirting and even saturated the brickwork and plaster, all of which had to be replaced.
The cost of climate change and flooding
Bryony’s story is one that’s being repeated more and more across the UK, with flood risk now one of the UK’s top climate change risks.
Scientists predict that one of the impacts of our climate emergency will be heavier rainfall and greater frequency and strength of storms. Figures show that England had its fifth wettest autumn on record in 2019, according to evidence from the Met Office. It also shows the number of winter storms has increased in the North Atlantic and that they are getting stronger. Heavy rainfall events are also becoming more frequent; warmer air carries more moisture, which means rains falling in heavier showers.
The financial impact of these storms and the associated flooding is increasing. Estimates suggest that the cost to the insurance industry of the storms that battered the UK in early 2020 could hit £425 million. By the 2050s the annual average losses from coastal and river flooding in England Wales could rise to between £1.6 and £6.8 billion. Imagine what that money could otherwise be spent on.
In the area surrounding Moorland where Bryony lives 165 homes were flooded. Across the region, 600 houses and 17,000 acres of agricultural land were affected. The cost of damage ran into the millions. But the emotional and psychological damage was the hardest for Bryony to bear:
People’s mental states are so massively affected. Because you’ve been through so much it still really affects you and will do for years to come.'
Local resident Bryony Sadler and her daughter Elsa
Local resident Bryony Sadler and her daughter Elsa
What’s to blame?
Climate change isn’t the only reason we’re experiencing more flooding. Over the centuries, we’ve got rid of one of the world’s greatest flood busting habitats – wetlands. And we’ve done so at our peril.
One of the reasons the area around Bryony’s home on the Somerset Levels is so susceptible to flooding is because historically what was once marshes were drained to create productive farming land. Grassland has disappeared and been replaced with crops like wheat and maize. With fields often left bare over winter, there’s now much more surface runoff, which is causing increased flood risk downstream.
As the water was lost, the land shrank and its rivers and drains ended up being higher than the land itself making this area, which is known as the moors, at a high risk of flooding.
Previously, these moors were a saving grace. They acted like vast reservoirs, storing the water until it can be pumped away. Some of the moors flood every year; Northmoor, where Bryony lives only fills up when rainfall is particularly high. Unfortunately for Bryony so much rain fell at the beginning of 2014 that the moors kept filling up, eventually causing her village to be flooded.
The Somerset Levels
People have been living, fishing and foraging on the Somerset Levels for millennia, and draining and farming the fertile land since the time of the Domesday book.
The seasonally flooded nature of wetlands of the Somerset Levels means they can support a huge range of wildlife; they contain 32 Sites of Specific Scientific Interest (SSSIs).
Floodplains: the cradles of civilisation
Watching our news reports you’d be forgiven for thinking that flooding was something that has to be prevented at all costs. Yet it’s easy to forget that for millions living around the world, seasonal floods are natural and in many places are something to be welcomed. For with them comes life-giving water.
They replenish the land with nutrients, boosting agriculture and providing food, water, resources and grazing to sustain them and their livestock the rest of the year. People have chosen to live on these fertile flood plains since the dawn of civilisation.
The vast, seasonally flooded maze of rivers, swamps and islands of the Mekong Delta provides essential livelihoods for millions across the region. In Cambodia, 46% of the population work on the country’s seasonally flooded lands around the Lower Mekong valley.
Ker-Boeung Salakhang lives in the Thong commune in Cambodia where he is a council member for the commune. As he explains, the flooding season is very important for the people who live in the area.
‘The floods bring soil to restore their farms and rice fields. The floods also bring fish which are an important food source for people and wildlife. The floods also fill the wetlands which are the water resources during the dry season.’
During the recent pandemic, it was to these wetlands that millions of migrant workers returned when their jobs in the cities disappeared overnight. For them they offered their best chance of staying resilient throughout the pandemic.
Ang Moeun is Community Chief in Prey Kla, a village in Boeung Prek Lapouv, one of the largest remnants of seasonally inundated wet grasslands in the Lower Mekong. He explains what happened:
‘After the outbreak of COVID-19, many people from Boeung Prek Lapouv who used to work in garment factories had to return home because their work was impacted. Now many of them go to the wetland to get their food and collect necessary things.’
Water lily, lotus, mushrooms and other vegetables plus rats, frogs, snails and fish; just some of the resources people have been collecting from their local wetlands in order to help feed their families during local lockdowns.
Flood-mitigating wetlands under threat
But these critically important wetlands are now under threat. Cheung Ek is a sprawling wetland found just south of Phnom Penh in Cambodia. It plays an important role acting as a natural store for 70% of the capital’s rain and wastewater. But it’s now in danger of being destroyed to make way for the development of a new city. There are warnings that if the wetland is lost it could place one million Phnom Penh residents at an increased risk of flooding.
There are also concerns that if wetlands continue to be lost, the city would lose its natural wastewater treatment system. Instead, the capital’s raw sewage would end up polluting nearby rivers and contaminating fish stocks, as WWT’s Office Manager in Cambodia, Saber Masoomi explains:
‘Phnom Penh has very little in the way of infrastructure to help treat its wastewater. The wetlands are the primary and free sources of the city’s wastewater treatment. If they’re lost, it will be a major issue for the capital.’
Cambodia isn’t the only country that’s seen a dramatic loss of its wetlands.
Across the world, a third of wetlands have been destroyed since 1970.
This loss has brought with it devastating consequences, hampering our ability to deal with the increasing number of floods we now face. Physical flood barriers like concrete walls and dams have an important part to play in protecting our homes and businesses from flooding. But they’re expensive, and we can’t afford to build and maintain vast flood defence schemes for every village, town and property that floods.
The solution?
Slowing the flow, returning to nature
Carina Gaertner is passionate about hedges. Today she’s working in the Doniford Valley in the Quantocks in West Somerset on a flood prevention project planting 300m of new hedgerow as part of a project with wetland conservation charity WWT. This is just one of a mosaic of natural interventions across the catchment, an approach that sounds revolutionary but creates an impression of an older, wilder landscape.
For two hundred years we’ve followed the ‘getting rid of water as quickly as possible’ approach, clearing out watercourses, straightening and sanitising them; making water flow away as quickly as possible. But the problem with this is that those further downriver get flooded.
But as Carina explains, she’s following an alternative approach to floodwater management. And it’s one that’s gaining ground around the world. By using ponds, hedgerows and natural features, Carina aims to slow the flow of water.
‘The idea of Natural Flood Management (NFM) is not an entirely new one. It’s an umbrella term for a range of different techniques that use natural features in the landscape like ponds, flood plains and wet woodlands to manage water, slow it down and reduce flooding.’
The premise is to hold water in the landscape for as long as possible to allow it to slowly pass through the catchment over a long period rather than rushing off the land in a flash flood. It encourages a change of mindset, a degree of letting go, of being less tidy and to an extent, letting our rivers and streams ‘rewild’.
Using wetlands to manage flood risk isn’t intended as a stand-alone alternative. However, increasingly it is being recognised that in some cases, they can offer a more natural and more cost-effective way to manage this risk.
‘Storms Ciara and Dennis – and communities that have suffered repeated flooding events in recent years – have highlighted to me the importance of making nature’s power part of the solutions we urgently need to tackle the challenge of flooding.’
What are the different flood management examples
and how do they work?
Working with the landscape
Poor land management contributes to flooding in some areas. This graphic shows how the way uplands are farmed can cause soil and water to flush into rivers, by denuding slopes of natural barriers and compacting land with cattle and heavy machinery.
But NFM strategies offer an alternative way of managing the land by helping to slow the flow of water and so significantly reduce the impact of flooding on homes and businesses.
Working with the landscape
Poor land management contributes to flooding in some areas. This graphic shows how the way uplands are farmed can cause soil and water to flush into rivers, by denuding slopes of natural barriers and compacting land with cattle and heavy machinery.