Background:

The River Erewash and the surrounding floodplains, wetlands, and marshes form a rich tapestry for wildlife that is of value to not only Derbyshire, but also Nottinghamshire. For a large proportion of its length the river forms the boundary between the two counties, with important wildlife sites in both, whether that be Erewash Meadows in Derbyshire, or Nottinghamshire’s Attenborough Nature Reserve. 

The River Erewash catchment is relatively small and mostly urban. Arising in Kirkby-in-Ashfield it flows southward, snaking along farmland, and through a series of towns including Ilkeston, Stapleford and Long Eaton. It is culverted though many of the towns and hidden from view – both detrimental for wildlife and a loss to local residents. It eventually flows into the Attenborough Nature Reserve, a series of lakes and wetland and a Site of Special Scientific Interest - a great spot to see many wading bird species. These lakes then feed into the grandeur of the River Trent and onto the Humber Estuary.

The name “Erewash” is thought to derive from the Old English term meaning a “wandering, marshy river”, a reference to its rich floodplains and meandering, “flashy” nature. Mining activities, agricultural intensification and urbanisation over a number of decades have since altered the nature and behaviour of the river. Various urban and industrial developments in the catchment have meant that many wildlife-rich areas are often isolated, others are in ecological decline due to a lack of management. Large stretches of unmodified and naturalised river do remain intact, and surrounding areas of wetland and floodplain have been preserved due to the difficulty in draining the floodplain for farming. A number of tributaries feed into the main river Erewash including Nethergreen Brook, Bailey Brook, Nut Brook and Gilt Brook – these act as important pathways for wildlife into the wider landscape.

Pressures.

The river Erewash has had a difficult past and has been subjected to every pressure man can throw at it - industry, urbanisation, rural and urban pollution. The most overwhelming pressure on the river currently is that of nutrient enrichment – and phosphate in particular.

Phosphates occur naturally in the environment but can be found in fertilisers, manure, sewage waste, detergents and industrial effluent. Whilst this nutrient is essential for plant life – too much of it in the water can cause environmental damage. It encourages large amounts of algal and plant growth which can stop light penetrating to the bottom of watercourses, and leads to a process known as eutrophication. This reduces the amount of oxygen that is dissolved in the water, negatively impacting fish and aquatic insect – and ultimately anything which predates them.

The majority of this phosphate in the Erewash comes from waste water. There are a number of sewer treatment works along its length, and whilst they are all equipped with facilities to strip out excess phosphate from the water, large amounts are still entering the watercourse. There is still a lot of progress to be made in this area and a number of organisations are working together to address this and get our waters pristine again.

Biodiversity

The Erewash is a great example of a recovering landscape, once peppered with mines and industry the land and watercourse are steadily improving in quality and wildlife is returning. Like many waterways the river Erewash and its banks form a valuable “blue corridor” for wildlife. They link many patches of nationally important habitat, allowing animals to migrate between them. Maintaining these wildlife highways is extremely important to allow unhindered access to breeding, foraging, and resting sites for many of our protected species, such as otter. 

Many organisations, including Derbyshire Wildlife Trust, are working together to restore lost links along the river and help return it to its former wandering, marshy glory. And these efforts are starting to reap their rewards. Otters have been recorded in greater numbers along the lower reaches of the river. This species saw a national decline during the 1960s and ‘70s largely attributed to a build-up of a toxic insecticide called Dichlorodiphenyltrichloroethane, commonly known as DDT.  Since this chemical was banned, increases in water quality and reduced persecution have allowed otters to recolonised areas from which they had been lost. 

The Erewash also contains a pondweed that is extremely rare in Derbyshire. Grass‐wrack pondweed is only known to be present in a handful of sites in the county where it grows under water in slow-flowing rivers and canals. It was formerly widespread in the area, but historic deteriorations in water quality have meant it is all but lost from the county. This makes the Erewash an extremely valuable refugia for this species. 

Water voles are in the ascendency on the Erewash. They have suffered a drastic decline and populations are now few and far between in the county, confined primarily to small watercourses and along canals. Derbyshire Wildlife Trusts Living Rivers Officer Kath Stapley is involved in the habitat improvement of monitoring of water vole. Kath says “the water vole population on the River Erewash is doing well; if you take a quiet stroll along the footpaths that run alongside the river you may be rewarded with a glimpse of these elusive creatures. We have volunteers monitoring the population by carrying out regular surveys, looking not only for the animals themselves but also for their droppings, footprints and other signs of where they have been.”

There are a number of barriers on the river preventing fish passage up and down the river. This is mostly an issue for migratory fish, such as salmon and eel. However, coarse fish are also affected as once washed over a weir it is extremely difficult to get back over, particularly for smaller or younger fish. This is another issue where partners and stakeholders are adapting a collaborative approach to solve the issue. Erewash Catchment Co-ordinator for the Environment Agency, Dr Ryan Taylor, says “I love the Erewash, I think it’s partly because it has so much potential, the river has quietly been improving and boasts water vole, white clawed crayfish and otter populations and I have seen Osprey feeding at Erewash Meadows  … Superb! My aspiration for the river is to return Atlantic Salmon, we are working on projects which would see this happen as soon as next year. Working with Derbyshire Wildlife Trust is brilliant, we have shared ambitions and the professionalism and commitment from the Trust means we are able to protect the river and also develop long term projects.”

The Erewash supports many invertebrate species that are recolonising this once polluted river. They have been historically reduced in number due to the presence of heavy metals in the mine water entering the river. These animals form the cornerstone for a healthy river system and it’s wonderful to see the large number of dragonflies, damselflies and mayflies darting or floating through the air on a summers evening. 

The habitats surrounding the water play a pivotal role in the health of the river. Many animals move between the habitats in search of food and refuge, and are therefore integral to a biodiverse landscape. Formerly widespread habitats, such as floodplain grazing marsh, can be found around the River Erewash and support distinct plant and animal communities. Other wetland features, such as lakes and ponds, can be found close to the river, these offer complementary habitat to the river allowing species to move between them in search of food or breeding habitat – great for osprey, water vole and a wide variety of insects. Areas of wet woodland and reedbed also border the Erewash creating important habitat for some of our most threatened bird species such as willow tit and bittern. This connected landscape is vital if we are to conserve our wildlife at a large scale – by reducing the fragmented nature of these habitats we can provide a home to a wealth of flora and fauna that would be a real asset to Derbyshire and Nottinghamshire.

The future of the Erewash

The Erewash still has a way to go to return her to her former glory. We’ve come a long way in improving the water quality in our rivers nationally, with restrictions about what chemicals can be used in pesticides and industry as well as improvements in waste water treatment. There are many gains to be made in further reducing the pollution in the river Erewash – as Dr Taylor says “it has so much potential” and we at the Trust agree. 

Our members and the general public can play a huge role in the recovery of this river. Even if it’s just noticing things about the river when you are out-and-about. For example, you can help to record pollution incidents. The first step is knowing what a pollution incident looks like, on the whole, rivers shouldn’t be foaming, opaque, or chocolatey brown after heavy rainfall – this may be a sign that something is entering the watercourse that shouldn’t be, whether it is detergent, sewage or sediment. You can report these incidents to the water companies and the Environment Agency and together we can clean up our rivers. 

Another key way to get involved is by telling us what you’ve seen! Send us your wildlife sightings to help us understand better the species that live along the river and this will help us track any changes in populations. Some of the most important wildlife to tell us about are protected species and invasive non-native species. One of the largest threats to our native wildlife along the Erewash is in the form of invasive species, such as mink, Himalayan balsam and signal crayfish, so it’s vital we know where they are so they can be addressed quickly.  

Finally, you can get involved in work parties or volunteering schemes to help us tackle issues and monitor wildlife – it’s a great way to support the trust and Derbyshire’s wildlife and does wonders for your wellbeing.