Review: 'River Restoration', Holnicote Estate, Somerset

'Three-year project on the National Trust's Holnicote Estate, Somerset was the first large-scale attempt to reset a UK river to fully reconnect its waters with the surrounding floodplain by filling in a 1.2km managed, straightened and deepened section of the River Aller to transform the area and dramatically create seven hectares of waterscapes and wetlands (equivalent to moire than ten football pitches)'.

(This photograph (left) shows the site during the early stages of the project.)

Sadly, the UK has lost over 90 per cent of its wetland habitats in the last 100 years, this dramatic loss is because of unsustainable farming and development practises, urbanisation and abstraction. 

Wetland environments protect us from extreme weather events and aid in the recovery post natural disaster, soaking up rain acting as a natural solution to flooding. Plant matter steadily decays and accumulates in the waterlogged conditions of wetlands, helping carbon sequestration and reducing air temperatures by up to 10 degrees celsius. Most wetlands are peat-forming, this organically-rich habitat is slow growing material, a crucial habitat for plants such as sundew and marsh violet, in turn supporting invertebrate and bird populations. Peatlands are not only sponges for rainwater, snowmelt and mist, but purify this water gradually releasing it back into the environment, regulating the flow of rivers, reducing flooding and maintaining flow in dry weather.

Home to a wide range of species from carnivorous plants to birds of prey, wetlands support an abundance of species, creating a diverse mosaic of ecosystems. These types of restoration projects can help downstream communities at risk of flooding.

The results of this 3 year project out of have been confirmed to be incredibly positive within 12 months of completion, with numerous inspiring outcomes which are granted to benefit the environment and our lifestyle as humans. With climate change altering Earth's atmosphere, resulting in extreme temperatures and weather changes, this it is an crucial time to prepare for theses changes as effectively as possible. Nature-based solutions play a pinnacle role in subsiding the upcoming weather issues we are guaranteed experience.  

Spanning more than ten football pitches, the development of the project has been monitored for the past 12 months by researchers from several universities (Exeter, Loughborough, Nottingham and Umeå in Sweden), studying the water flow and quality and changes to the habitat. Dr Richard Mason, researcher from Umeå has said:

"Put simply the system has moved from a very tidy area with little for wildlife to a messy complex jumble of waterscapes and diverse habitats that is full to the brim with a huge variety of plants and animals." 

They have experienced dramatic changes in the amount of aquatic habitat, "a huge 1780 per cent increase, with developed diversity, slower flow of wetlands and an overall increase in areas of faster flowing water and ponds, resulting in new habitat types providing opportunities and refuge for wildlife leading to greater abundance and resilience".

This project ultimately signifies a great success with "reduces downstream, flood peaks (38 per cent lower), meaning during storms less water is leaving the site at a slower rate, demonstrating such river restoration projects can help downstream communities at risk of flooding." Although wetlands must be carefully crafted, these positive results can still be transferred into other locations where they are flooding issues with little time pressure as wetlands are able to establish themselves so quickly.