At one point or another, you have probably heard that you won’t find straight lines in nature. As it happens, this little bit of wisdom is incorrect. While they may not be the norm, many examples of straight lines exist in the natural world. See the silken segments of a spider’s web and the trunk of a pencil pine tree, for two examples.
Residents of the UK may be tempted to add one of the country’s many stretches of straight-running rivers to this list. But they would be wrong. Rivers running in a straight line are not natural phenomena, but evidence of human intervention. And they are numerous. Only 3% of UK rivers remain “free-flowing,” or without modification.
As is true of so many of our efforts to control nature, the straightening of rivers has had disastrous environmental consequences. In this article, we will look into how we got to this point, what can be done, and the work being done to rewiggle our rivers.
How did we get here?
Rivers are an inescapable enabler of the UK’s economic development. They are natural arteries for transportation and have long been powerful drivers of trade and industrial growth. Many are naturally navigable by boat, but many require modification before they can be exploited.
The process of modifying rivers is known as “canalising,” whereby they are artificially straightened, deepened, and/or reinforced. The golden age of canalising came during the Industrial Revolution when massive increases in coal, iron, and textile production necessitated efficient transport. But the practice didn’t stop there. Between 1933 and 1983, 8,500 kilometres of rivers were significantly altered in England and Wales.
Why mess with rivers in the first place?
In some ways, our obsession with altering rivers makes a lot of sense. Removing their wiggles, or meanders, not only makes rivers easier to travel but also separates them from surrounding floodplains. This makes huge tracts of land available for agriculture. As much as 60% of agricultural land in the UK has been drained in one way or another.
Canalising also provides a temporary form of flood protection. By deepening and widening a river its flow capacity is increased. A smoother, straighter, deeper river can move a lot more water out of an area much faster. This reduces the risk of the river overflowing, protecting nearby infrastructure and enabling urban development.
Spot the problem? All that water keeps on moving downstream. So rather than preventing a flood, canalising can increase the risk of flooding downstream. This postponement of consequence is emblematic of our attitude towards the environment in general. Immediate benefits are enjoyed at the expense of future generations and anyone further downstream.
Unfortunately, we have made a habit of designing solutions that cannot meet the demands of our changing climate. In 2022 we learned the hard way that our runways, roads, and railways are incapable of withstanding periods of extreme heat and Aviva published a report this year showing that one in thirteen homes built in the last decade were built in a flood zone.
The negative effects of canalisation.
Flooding isn’t the only problem that arises when a river loses its wiggle. The meanders of a river should slow the flow of its water, allowing sediment to settle and creating ideal conditions for fish spawning. Without natural curves, the now faster-flowing water erodes river banks and strips the riverbed of essential nutrients. The result is an epidemic of depleted freshwater ecosystems driving a decline in fish populations and damaging the UK’s biodiversity.
Perhaps more alarmingly, by separating rivers from their floodplains we have sabotaged our climate resilience. Wetlands are incredibly effective contributors to global carbon sequestration but the UK has lost 90% of its wetlands, and canalisation is partly responsible.
The propensity of canalisation to worsen climate change-related events is particularly relevant at the moment given the flooding caused by Storm Bert. The River Calder in West Yorkshire, where flood warnings have been issued this week, has been subjected to significant canalising in the past. Fortunately for the River Calder, it has also been the beneficiary of a restoration project aimed at reviving the river’s ecosystem – and there are many more projects like this.
What can we do now?
We owe a lot to our rivers. As we have seen they played an important role in the UK’s economic growth and they still provide essential benefits, like hydropower energy and transport links. Sure, they also expedited inland Viking raids, but no one is perfect.
Believe it or not, previously straightened rivers can be rewiggled and restored to their former glory. Rewiggling is a major undertaking that involves extensive excavation works to restore natural meanders, remove artificial obstructions, and create renewed freshwater habitats. Here’s a look at some of the most impactful rewiggling projects in the UK:
- Swindale Beck, Cumbria—This river was straightened over 200 years ago to create farmland, leading to dramatic damage to habitats along the river and higher flood risks downstream. At a cost of £212,500, natural meanders and gravel beds were reintroduced, allowing salmon to return to spawn for the first time in centuries.
- Goldrill Beck, Lake District—Extensive flooding in 2015 prompted the restoration of Goldrill Beck’s natural floodplain in 2021. By removing artificial obstructions and reintroducing meanders over 1.6km of the river, peak flood flows were slowed by two to three hours. The restored floodplain now holds 1,800 cubic meters of sediment and provides living space for species like otters and wading birds.
Projects like these showcase the potential power of rewiggling and its role in reversing the ecological damage of river modification in the UK. As climate crises worsen, rewiggling does offer an effective way to address multiple challenges: carbon storage, flood resilience, and habitat loss. Unfortunately, rewiggling also comes with many challenges. Not the least of which is funding, which has to be in place for a long time after work is completed to ensure that restored rivers are monitored and maintained.
These projects also highlight a dangerous pattern of postponed accountability in our approach to the environment. Addressing the resulting challenges requires systemic solutions that link progressive government policy with financial support and a more holistic take on environmental management. Frameworks like the Environmental Land Management Scheme (ELMS) are a good start – but more change is needed to reshape our landscape and rewiggle our rivers.
Be curious!
- Look for opportunities to donate or get involved with local river restoration efforts here.
- Explore detailed case studies of river restoration projects across the UK and Europe here.
- The Natural History Museum is an incredible place to visit for anyone interested in learning more about freshwater habitats.
Featured image by K. Mitch Hodge, via Unsplash.
