Of dragons and damsels

Just around the river bend

River valleys are a key landscape feature in Suffolk, home to some of our most iconic species, like water voles, otters, and kingfishers. They act as blue wildlife corridors, connecting different habitats and provide multiple ecosystem services. And yet, humans have abused rivers by changing the way they flow through the landscape or releasing waste into them. Suffolk Wildlife Trust is working to change this. BY ALICE WICKMAN

OTTER: TONY PHELPS ALAMY Otters are a keystone species in rivers and waterways.

Our rivers are home to a myriad of species and provide a vital resource for humans, and yet they have faced years of degradation. Even though we know the damaging impacts we are having on these fragile ecosystems, sewage and other pollution enters our rivers, including making national headline news last year. Suffolk Wildlife Trust wants to change this and has been working on river conservation projects for over 20 years. Our earlier work focused on water vole conservation, which helped lead to the recovery of water voles across every major river catchment in Suffolk. In more recent years, our work has focused on river restoration projects, which aim to repair some of the damage done to our rivers through human modifications and pollution.

Restoring natural processes

In a healthy river system, with natural meanders, pools, and riffles, a wide range of species will thrive. Some prefer the sheltered waters on the inside of a river bend, while others benefit from faster-flowing sections. Plant material in the river channel provides cracks and crevices for invertebrates to hide in, in turn providing food for fish and other animals.

It was once thought that rivers should carry water away from towns and villages as quickly as possible, so they were diverted, straightened, confined to concrete channels, or even forced underground. When our rivers are engineered in this way, the brilliant variety of flow patterns and habitat structures are taken away. Through our river restoration work, we aim to

recreate this variety and allow rivers to recover their natural processes.

In 2018, Suffolk Wildlife Trust completed two river restoration projects at our Knettishall Heath and Black Bourn Valley Nature Reserves, and in 2019, three more at different sites in the River Blyth Catchment. During each, we worked in partnership with the Environment Agency to create different habitat features and flow patterns by either physically recreating a meandering river channel using machinery or the installation of woody material into the river channel.

A whole-catchment approach

Looking beyond our nature reserves, and thinking bigger, river restoration depends on enlisting the support of groups of landowners within a catchment. Since 2019, we have been working in the River Blyth catchment, taking a whole-catchment approach to improve the river habitat and address water quality issues. A catchment-wide approach is necessary as no single site along a river valley is isolated: farms, communities and businesses are all connected by the river.

As well as the in-channel work on the River Blyth, we have engaged with over 30 land managers and advised on sensitive river management, as well as methods for preventing pollution and sediment runoff entering the river. Over 20 volunteer River Wardens have been trained to monitor the health of the river through invertebrate surveys and water quality monitoring. This gives us a picture of what is going on in the catchment and can help us to identify pollution incidents in the future.

The River Warden volunteers also planted over 1,000 trees and shrubs along the banks of the River Blyth to improve the river habitat and help mitigate the impacts of climate change. As well as their amazing carbon storage potential, trees on the riverbank serve an important function for wildlife, with their extensive root systems providing shelter for young fish and protecting the riverbank from erosion. The trees also offer shade, which helps regulate water temperatures in the summer. We used locallysourced native species like alder, oak and willow. These interventions, combined with others across the whole river catchment, allow us to tackle the issues at scale, rather than at isolated sites.

New ways of working

A whole-catchment approach to river restoration is a new way of working for Suffolk Wildlife Trust, but our successful work on the River Blyth will act as a model for future projects. We aim to deliver

Marsh harriers were hunted to extinction and then badly impacted by pesticides like DDT. Wild rivers blend into the countryside, twisting with the ebb and flow of the landscape.

Suffolk has great potential water vole habitat with river valleys, coastal grazing marshes, ponds, ditches, lakes, fens and reedbeds. The River Deben is one of Suffolk's iconic rivers. The Deben Estuary is nationally protected as a SSSI, and internationally as an SPA.

RIVER WORK

Our successful work on the River Blyth will act as a model for future projects

Alice Wickman

is Wilder Rivers Adviser for Suffolk Wildlife Trust.

larger-scale river restoration projects that will link the river to its floodplain, benefiting wildlife in the wider landscape as well as the river channel. All this amazing river restoration work helps us ensure that species like the water vole continue to have a home in Suffolk. Our work on rivers forms a key part of our vision, including our goal to see 30% of Suffolk managed for nature by 2030. Much more hard work will be needed to ensure that Suffolk’s rivers recover and our wildlife thrives.

Get in touch

If you own land within a river catchment, our Wilder Rivers Adviser can offer advice on how you can manage your land for wildlife. Contact alice.

wickman@suffolkwildlifetrust.org

TREE PLANTING ON RIVER BLYTH: SARAH GROVES

Brushwood

mattresses on the Little Ouse at Knettishall Heath were built using local timber secured to the riverbed. These form an area for wetland plants to provide cover for young fish.

Major works at Black Bourn Valley nature reserve created a more natural

meandering channel

A flow deflector and reconnected it to the floodplain.

on the River Blyth, made from timber fixed to the riverbed diverts the flow of water, encouraging natural meanders to form. These structures are used by wildlife, including otters.