Wildlife experts warn that the threat to the first wild beaver colony living on an English river for over 400 years is raw sewage. 

Sewage from Honiton treatment works in Devon is contaminating the beaver colony along the River Otter, according to Devon Wildlife Trust. 

River Otter is the site of a successful official beaver trial reintroduction, where the creatures were given permanent right to remain in 2020 by Defra.

But the sewage plants spilt 137 more times last year, totaling 2,442 hour of spillage into river. This can lead to fatal infections and diseases for beavers.  

The trust’s announcement follows footage last week showing untreated waste pouring into Langstone Harbour in Hampshire, for 49 hours straight. 

A Eurasian beaver (Castor fiber). Castor includes two extant species, the North American beaver (Castor canadensis), native to North America, and  the Eurasian beaver. Beavers are native to the UK and used to be widespread in England, Wales and Scotland

A Eurasian beaver (Castor fiber). Castor includes two extant species, the North American beaver (Castor canadensis), native to North America, and  the Eurasian beaver. Beavers are native to the UK, and were once common in England, Wales, and Scotland.


Scientific name: Castor fiber

Head-body lengthFrom 30 to 35 inches 

Tail length: 11-15 inches

Weight: Maximum 38kg

Lifespan: 7 to 8 Years

Diet: Aquatic and herbaceous plants in summer and bark of broad-leaved trees in winter.

Source: PTES 

Mark Elliott, who leads the beaver project at Devon Wildlife Trust, told the Times that the discharges into the River Otter were ‘a massive concern’. 

He said that there are a lot of nasties in sewage that could potentially have an impact on them, such as bacteria and viruses. 

MailOnline has contacted South West Water, which operates the sewage overflow site, for comment.  

The excessive rainwater causes Britain’s sewer system to fail, which can lead to the destruction of natural wildlife.

Water companies are legally permitted by law to release rainwater and a smaller amount untreated sewage directly into rivers and seas to stop waste from backing up in homes and streets.

It was revealed last week that water companies will soon be required to reduce the amount they dump in this way, following a public outcry. 

Many of the opposition was caused by the cost to replace a national sewage system that was built during the Victorian era. Despite the potential impact on the environment, it was still affordable.  

MPs recently voted against amending a bill to stop water firms dumping raw sewage into Britain's rivers and seas (stock image)

Recent vote by MPs against amendment to a bill that would have stopped water companies from dumping raw waste into Britain’s rivers or seas (stock illustration)

There are two species of living beavers: the North American beaver, (Castor canadensis), which is native to North America, as well as the Eurasian beaver, (Castor fiber). 

The Eurasian bear is a native British species that used to be common in England, Wales, and Scotland. 

According to the RSPB, they were extinct in 16th-century England, primarily because of the hunting for fur, meat, and ‘castoreum’ (a secretion used as medicine and food).    

Now, beavers are expanding their range naturally in Britain and are seen as ‘nature’s engineers’ for their ability to restore wetland habitats through dam-building and felling trees.

This activity slows down, stores, and filters water in the landscape. It attracts wildlife and reduces flooding downstream. 

More than a decade ago, Beavers appeared on the River Otter in Devon. At first, there were calls for their removal. 

The Eurasian beaver faced extinction Britain but there have been reintroductions in certain areas including Scotland, Devon, Cornwall and Kent

The Eurasian beaver was threatened with extinction in Britain. However, there have been reintroductions in some areas, including Cornwall and Kent.

After a five year environmental assessment, the Government determined that beavers can remain for good and will continue to expand their range naturally. 


Avon Wildlife Trust revealed that three generations of beavers were discovered wild in the Avon catchment, Bristol and Bath, for the first-time in 400 years.

The ‘family’ of beavers in Avon includes three children, all born this year and at least one year old from last year. 

The sightings were made by both the public as well as Avon Wildlife Trust staff working in the area. However, it doesn’t know the exact numbers.

Avon Wildlife Trust said that it won’t reveal the exact locations of beavers to ensure their security.

The origins of the beavers living in this area are unknown. However, it could be traced back at a release that occurred in 2000 on the Somerset-Avon border or the wild population in Devon along with the River Otter.  

A University of Exeter five-year study published last spring shows that beavers have been reintroduced back to the river. We have been able to reduce the risk of flooding, and we have also seen an increase in wildlife.   

River Otter is home to England’s only wild beaver colony. However, they have been introduced into enclosures throughout a number English counties to help with flooding and provide habitat for other wildlife. 

Avon Wildlife Trust announced in September that three generations of beavers were found in Bristol and Bath, for the first-time in 400 years. 

Another reason they were found on rivers is illegal releases or escapes. They can also be found in parts of Scotland, where the population now exceeds 1,000, according to a recent report. 

According to Scottish Wildlife Trust the Eurasian beaver populations are now widespread and estimated at 1.2 million across Europe.

Both the North American beaver and the species are known for their sharp teeth, which they use to cut down trees and shrubs and create dams.

These dams provide protection for semi-aquatic animals from predators like wolves and bears by creating large bodies of water.

They don’t eat fish, contrary to common belief. Instead, they prefer to eat aquatic plants, grasses, and shrubs in the summer months, and woody plants in the winter. 

They will often keep food underwater to be able to access it in case the water freezes. 

Beavers are good swimmers and a reservoir of water allows them to play to their strengths, escaping from those higher up in the food chain.

The biggest beaver dam ever discovered measured 2,790 feet (850m) – more than twice the length of the Hoover dam between the US states of Nevada and Arizona.

The woodland construction, found in the southern edge of Wood Buffalo National Park in Northern Alberta, Canada, was so expansive it could be seen from space.


There is some debate about whether Beavers should have gone into the wild. 

This is why the illegal wild animal rewilding in Scotland occurred, despite concerns that the government wouldn’t support an official project. 

These are the points that either side of the argument has to offer:


Together with beavers, the UK’s wetlands fauna and flora evolved.

They reduce siltation which can pollute waterways and cause silt and clay to build up.

Their dam-like habitats help reduce flooding downstream after heavy rain.

Beavers create ponds that are used by two-thirds (or more) of the UK’s wildlife.

The public is supportive of restoring wild animals to their natural habitat.  


The UK’s rivers have changed drastically since the disappearance of beavers.

British waterways are in poor condition, potentially putting beavers at danger.

Beavers can spread foreign tapeworms to humans and dogs.

They can cause damage to both local infrastructure and forests.

Sometimes, dams can cause flooding to worsen than they prevent.