It may sound like something from a dystopian movie, but ‘Stage Zero’ has just created a paradise.

By Daniel Graham

Published: Saturday, 19 October 2024 at 15:51 PM


Something remarkable is happening in a quiet corner of Somerset in south-west England: the creation of an Eden. And it’s all thanks ‘Stage Zero’ – or ‘Stage 0’ – an innovative river restoration technique originally developed in Oregon, USA.

A year after completing an ambitious Stage Zero project on the Holnicote Estate in Somerset, rangers say the site is unrecognisable.

 “It has gone bananas in terms of the amount of wildlife and lush vegetation growth that we’ve seen,” says Holnicote Estate ranger Jack Siviter. But it’s not just nature that has benefited from the project – the work has improved water quality and reduced flood risk for downstream communities, too.

Rangers sowed and planted a variety of plants and wildflowers suitable for wetlands, which are now thriving at the Stage Zero site on the Holnicote Estate/National Trust Images (View It 360)

The objective for the Holnicote team was to reconnect a 1.2km section of the River Aller – the estate’s main watercourse – to its natural floodplain. The process involved filling in a straightened, artificially deepened stretch of the river, transforming the area into a thriving seven-hectare wetland – roughly the size of ten football fields.

Wetlands are critical habitats, not only for their biodiversity but also for their ability to store water, reduce flood risk and capture carbon. Yet, more than 90% of the UK’s wetlands have been lost over the past century, contributing to the decline of many freshwater species. By restoring the natural dynamics of the River Aller, the Holnicote project has provided a powerful example of how we can begin to reverse this trend.

Despite facing England’s wettest 18 months on record shortly after completion, the restored floodplain proved its worth.

It absorbed floodwaters, slowed their flow, and reduced downstream flood risks, safeguarding local communities. “We had just the worst winter you can imagine post restoration in terms of the number of storms and sheer volume of rain,” says Ben Eardley, the National Trust’s project manager. “The site responded really well… demonstrating the value of the restoration in providing resilience to hydrological extremes.” 

Sparrow hawk
A sparrowhawk surveys its hunting grounds at Holnicote Estate/National Trust Images (Richard Bradshaw)

Researchers from several universities, including Exeter, Nottingham and Umeå in Sweden, have been closely monitoring the site. Their findings are impressive. Groundwater levels have risen significantly, in some places by over a metre, turning the floodplain into a vast, natural sponge that stores water during floods and releases it gradually in dry periods. This not only helps mitigate droughts but also filters sediments and pollutants, improving water quality downstream.

The restoration has also brought a burst of life to the river system. “There is a huge variety of plants and trees starting to shoot up across the wetlands, such as greater tussock sedge, which can grow to over two metres tall,” says Siviter. “This will provide a rich landscape for wildlife to thrive within.   

“Thanks to the increased wetted area we’ve seen loads of water-loving creatures, like wild waterfowl, water voles, eels, lamprey, grass snake, trout and birds such as red kite, buzzard, kestrel, sparrowhawk, swallow, swift and sand martin.  

“The martins, swifts and swallows are all using the site for feeding and nest building, while the birds of prey are using the site for foraging – which is in part due to the rewetting but also the longer sward. 

“The constant supply of water has also resulted in the site being very green and lush with thousands of wildflowers, like wild carrot, providing food for pollinators.   

“As a consequence, we’ve seen raptors such as kestrels, herons and deer and even barn owls

“One of the coolest species we’ve seen is a green sandpiper – which is a great indicator species for healthy, lowland wetland habitat,” Siviter adds.

Water voles, a species at risk in the UK, are also returning, with signs of a growing population throughout the wetland.

The success of the Holnicote project offers hope for the future of river restoration in the UK. By allowing rivers to follow their natural courses, we can create resilient, wildlife-rich landscapes that benefit both nature and people.

Main image: Deadwood at the Stage Zero site is a valuable habitat for insects, while the greater tussock sedge growing in between is an important refuge for species such as water voles/National Trust Images (James Beck)

More wild stories from around the world