For centuries meandering rivers have been straightened – but experts say restoring their natural bends and curves can prevent flooding and create healthy habitats for wildlife.

Swindale Beck, a stream in Cumbria, in the heart of the UK’s Lake District, meanders through fields, farmland and valleys. However, not long ago, the river took a far more linear course.
A healthy river should be sinuous, free flowing and replete with wildlife. In Britain, however, 97% of rivers are fragmented by artificial barriers like weirs. Now, there is at least one artificial barrier for every 1.5km of stream in the country. And for centuries rivers have been slowly canalised – or artificially straightened – to stop water from flooding and spilling onto farmland and houses.
But removing a river’s natural meanders has, in fact, achieved the opposite effect. Instead, it’s disrupted the flow of rivers and degraded aquatic habitats, water quality and heightened flood risk. As the poor health of Europe’s rivers and streams continues to make news – due to dwindling wildlife, sewage pollution and agricultural runoff – communities are turning towards natural solutions to restore their rivers.
RSPB It took a team of diggers three months to put Swindale Beck’s wiggles back where they should be (Credit: RSPB)RSPB
It took a team of diggers three months to put Swindale Beck’s wiggles back where they should be (Credit: RSPB)
Some rivers are being restored with natural flood management techniques (NFM), such as leaky woody dams, tree planting and beaver pens. One idea is to add wiggles back into rivers, streams and tributaries. Across the world, from the Netherlands, the US and the UK, rivers are slowly being re-wiggled, to return them to their natural course. And, in the UK, the rewards are starting to pay off, with fish, birds and invertebrates flocking back to rivers in Cumbria and West Sussex.
You want riffles where the water flows over stones and gravels, making bars and islands – Glen Swainson
Two hundred years ago, Swindale Beck was straightened out to create more space for farmland. But since 2016, a project has been underway to undo this process and restore the river to its natural state. Led by the Royal Society for the Protection of Birds (RSPB) the goal is to create more diverse habitats, structures and morphology.
The ideal river is “very dynamic, messy and chaotic”, says Glen Swainson, the RSPB’s Site Manager at Wild Haweswater. “You want riffles where the water flows over stones and gravels, making bars and islands,” he says. “When the river is more braided you have multiple channels across the floodplain that separate and rejoin each other.”
After studying the valley to locate the original path carved out by the river, the charity enlisted a team of diggers to reshape and create new channels. The project was in conjunction with the Environment Agency, Natural England and the water company landowner (United Utilities) and cost over £200,000 ($260,000) to re-wiggle the 1km (0.6-mile) stretch.
David Morris Birds like the dipper are flocking back to re-wiggled rivers (Credit: David Morris)David Morris
Birds like the dipper are flocking back to re-wiggled rivers (Credit: David Morris)
First, they conducted a study of the area to map the original path of the river, before recruiting a team of diggers, who spent three months carving out this bendy path as closely as possible. Swindale Beck is now about 180m (590ft) longer than the canalised stream that had flowed through the valley for over two centuries.
According to Tom Hayek, a natural flood management specialist at the Wildfowl and Wetlands Trust (WWT), adding meanders into rivers has two draws – it alters both the speed and the volume of water. Firstly, it decreases what’s known as flow conveyance. “This is the amount of water that a river can move downstream,” says Hayek. “When the length of the river is increased, you spread water over a wider area. “This allows more water to sit up in the headwaters, which is where re-wiggling usually happens, rather than in a pinch in towns downstream.”
The second impact is on speed. Put simply, the more structure you add to the morphology of a river, the slower the water will move down it. If it’s straight, water will “fly” through, says Hayek. “The speed and the volume that builds up as tributaries feed in means at some point in the river there’s no capacity to hold the water and flooding occurs,” he adds.
In the past, it was common to dredge rivers to create more capacity to cope with floods but, says Hayek, this does little to stop the root of the problem. Instead experts are moving towards natural flood management techniques, to restore rivers to their full floodplain.
Devastating floods spread across Europe

Rivers are in the spotlight in Europe this week after catastrophic floods left a trail of devastation across Austria, Poland, the Czech Republic and Romania. More than 20 people have died and thousands of people have been evacuated, including the entire town of Nysa in Poland – more than 40,000 people.
While restoring rivers could help reduce the impact of smaller floods, experts say it wouldn’t be enough to prevent the kinds of extreme floods seen in Central Europe in the past few days, as the masses of water are too large to be absorbed.
Scientists warn that climate change is leading to increased rainfall and more floods in some areas of Europe as the warmer air holds more moisture. Restoring rivers to their natural state, removing dams and managing floodplains could help us cope with that higher flood risk, according to experts, and various restoration projects are planned or underway across Europe as part of this effort.
When the flow of water is slowed, it creates deeper pools for fish to congregate and rest. Areas of the river where finer gravel has accumulated are a perfect spawning habitat for salmon that would have swum past before, says Swainson.
After Swindale Beck was straightened the results were “mind blowing”, says Annabel Rushton, the visitor experience manager at Wild Haweswater. “A lot of nature conservation is a long game. You plant a tree, you’re not going to in your lifetime see that it reached its full potential. But within three months of that river being re-wiggled the salmon were spawning in that one kilometre stretch for the first time in over 150 years,” she says.
Although the salmon was the poster boy of river restoration, they also noted an increase in trout and minnows congregating. Then, there were the knock-on-effects. Water-loving vegetation returned, providing cover for young fish to feed and hide.