MY KOLKATA EDUGRAPH
ADVERTISEMENT
regular-article-logo Wednesday, 23 October 2024

A radical approach to flooding in England: Give land back to the sea

When a huge tract of land on the Somerset coast was deliberately flooded, the project was slammed as “ridiculous” by a local lawmaker. But the results have been transformative

Rory Smith Steart Marshes (Somerset, southwest England) Published 23.10.24, 06:07 AM
A flooded area in the Hingalganj block of the Sunderbans after the Amphan cyclone in May 2020.

A flooded area in the Hingalganj block of the Sunderbans after the Amphan cyclone in May 2020. (File picture)

The rain has fallen for what feels like two years straight: in drizzles, in showers and, with troubling regularity, in downpours.

The weather has always been Britain’s favourite topic of conversation. The clouds are familiar. Increasingly, though, they are also a threat.

ADVERTISEMENT

In September, a month’s rain fell in a single day in some parts of England. The 18 months to March 2024 were England’s wettest in recorded history.

Even on an island that has built at least part of its identity around tolerating inclement
weather, it has been impossible to ignore the deluge.

Flooding has submerged fields, ruined homes, and at times, cut off whole villages.

As sea levels rise and extreme weather becomes more common, experts say that Britain’s traditional defences — sea walls, tidal barriers and sandbanks — will be insufficient to meet the threat. It is not alone: in September, deadly floods in Central Europe led to the deaths of at least 23 people.

But on a tendril of land curling out from the coast of Somerset, in southwestern England, a team of scientists, engineers and conservationists have embraced a radical solution.

In a project costing around $26 million, tidal waters were allowed to flood the Steart Peninsula in 2014 for the first time in centuries.

Rather than attempting to resist the sea, the land was given back to it. It was, in the words of Alys Laver, the conservationist who oversees the site, a “giant science experiment”.

A decade on, its results might offer a blueprint for how some parts of Britain — and the rest of the world — might adapt to the reality of climate change.

‘Ridiculous scheme’

When Laver first visited the peninsula just over 10 years ago, it looked like a “moonscape”, she recalls. Acres of farmland, used as pasture for dairy and beef farming, were being churned up by bulldozers and excavators. Fences, hedges and ditches were being levelled. Almost half a million cubic metres of soil was being removed.

A new creek system was dug out, snaking inward from the river Parrett, whose waters flow into the Bristol Channel and out into the Atlantic Ocean.

Laver was there on behalf of her employer, the Wildfowl and Wetlands Trust, a charity that shaped the project alongside the Environment Agency, the government body responsible for protecting England’s land and coastline. The idea was to turn what had been farmland into salt marsh, an ancient ecosystem that soaks up water as the tide comes in and releases it as the sea retreats.

It was not a universally popular plan. Farmers were paid around £5,000 an acre to give up their land. “Not everyone was in favour,” said one local farmer, Andy Darch. “I thought it might bring opportunities. But there were plenty who wanted the traditional defences to be strengthened. They felt that the government was staging a managed withdrawal from the sea defences.”

One displaced farmer, Robert Pocock, told a local newspaper that the plan was “environmental vandalism”. Ian Liddell-Grainger, the area’s then Conservative Party lawmaker, denounced it in Parliament as “an extravagant, ridiculous scheme”. Describing flooding in Somerset as “an almost annual crisis”, he accused the Environment Agency of believing “the levels should be allowed to return to the swampy wilderness that they were in the Middle Ages”.

That was actually sort of true.

Salt marsh, which is created by the deposits of fine mud and silt left behind by retreating seawater, has been around for thousands of years. It was used for salt making and for grazing animals in the Roman period.

Over the centuries, marshland was increasingly viewed as unproductive. Thousands of acres were drained and turned into arable land or developed for housing and industry. Since 1860, Britain has lost 85 per cent of its salt marshes, according to the UK Centre for Ecology and Hydrology, a research institute.

Returning Steart to swampy wilderness was, in part, an acknowledgment that the overdevelopment of coastal land had made flooding more likely, not less.

And so, as the sun rose on September 8, 2014, the tide was allowed to flood the peninsula. Water flowed through a new gap, about 660 feet wide, and then into channels and rivulets that, from above, looked like the veins of a leaf. The land had been surrendered. The experiment had begun.

Selling mud

The thing with marshland, Laver acknowledged with a rueful shake of the head, is that it is not romantic. Objectively, it is wet mud. And wet mud is not the sort of thing that excites people.

Still, on an overcast day earlier this year, as we strolled through a world at least partly of her creation, she could not keep the wonder from her voice. Beneath the tranquil veneer of the marsh, pocked with pools and streams, there was a remarkable sense of activity. “It solves so many problems,” Laver said.

The marsh acts as a natural and hugely effective bulwark against flooding, absorbing and slowing tides before they can encroach inland. Even last winter — the wettest anyone in the area could remember — the village at one edge of the peninsula did not flood. Paths through the marsh remained passable. A steep bank, covered with grass and significantly higher than the old flood wall, now borders the river.

The area is also a haven for wildlife. Bird-watching blinds with giant windows offer glimpses of godwits, plovers, oystercatchers, egrets and herons. A growing population of avocets — black-and-white wading birds with distinctive, curling beaks — has gathered around the pools of brackish water.

And the marsh has, over time, become a source of pride to the local population. Darch, who spent much of his career as a poultry farmer, started grazing cattle there in 2019, at the invitation of the Wildfowl and Wetlands Trust.

It is not without complications: This year, Darch found himself watching the sky nervously, wondering when the weather would be dry enough to move his cattle back onto their pastures. If the ground is too damp, he explained, it might create health problems in the cows’ hooves. “They like to have nice dry feet,” he said.

But the rewards are plentiful. On the marsh, the cattle are not corralled by fences; instead, their movements are governed by digital collars, which play music to discourage them from drifting into certain areas. Their diets are varied and organic, meaning they provide high-quality, free-range meat.

The alliance between the conservationists and the local population has helped to overcome initial objections to the project.

Laver now oversees a small army of volunteers who help maintain the marsh — trimming hedges, clearing paths. So many want to help that there is a waiting list.

There is, though, another benefit to the project at Steart. The beauty of this wet mud, after all, is not in how it looks, but what it does.

Carbon sponge

The most obvious effect of the salt marsh at Steart is in how it counteracts some of the consequences of climate change: absorbing the increasing volume of water that pours from the sky and swells from the banks of the river Parrett.

But it also helps address the underlying cause.

As they planned the project at Steart, Laver and her colleagues knew that salt marsh trapped carbon. It does this in two ways. The plants that thrive in salt marsh grow quickly, drawing carbon from the atmosphere. And the soils in the marshes are largely anaerobic, meaning they break down carbon in the sediment left behind by retreating tidal waters very slowly — over hundreds, or thousands, of years.

What was not certain was how effective the marsh might be at trapping carbon.

The data that has emerged, a decade in, is encouraging. “We’ve been as high as 19 tonnes of carbon per hectare, per year,” Laver said.

That figure is meaningless to most, but she is used to explaining it: “It’s the equivalent to charging 15 trillion phones” every year, she said, or “heating 33,000 homes”.

That achievement comes with two caveats. One: Laver knows the marsh will not continue to capture carbon at such a prodigious rate.

And two: even that high-water mark represents a fraction of Britain’s total emissions.

“We have done studies on all of the natural marshes in Britain, and they capture somewhere in the region of 46,500 tonnes of carbon a year,” said Craig Smeaton, a lecturer in geography at the University of St. Andrews. “Britain’s carbon footprint is about 58 million tonnes each year.”

New York Times News Service

Follow us on:
ADVERTISEMENT
ADVERTISEMENT