Environment Agency Update on River Crane pollution incident  – December 2012

The River Crane is an important river for West London. Not only does it provide a valuable green corridor for wildlife, it also gives local people a rare opportunity to get close to nature within an urban environment. On the last weekend of October 2011, we were informed of a major pollution incident. A seven mile stretch of the River Crane and parts of the Duke of Northumberland’s River had been polluted with crude sewage.

The severity of this pollution incident and its impact upon the river only became apparent during the days that followed. Our officers worked with other organisations around the clock to minimise the environmental damage. The pollution had a devastating effect on wildlife and was responsible for killing thousands of fish. The clean-up that followed has taken many months, many people and a lot of hard work.

One year on

We remain committed to restoring the River Crane and Duke of Northumberland’s River. We are also committed to holding to account those responsible for the pollution. Our criminal investigation is progressing well and a number of our staff are involved in gathering evidence and assessing the incident’s severity. We are working hard to complete our investigation as soon as possible, however the case is very complex and involves a number of parties. We are unable to confirm if or who we will be prosecuting at this stage, as this may prejudice the case. In the meantime, we continue to assess the incident’s long-term impact on the ecology of the river.

We are working with members of The Crane Valley Partnership and other community groups to prioritise what work can be carried out to assist the recovery. Today there are early but encouraging signs of returning life. This has included natural recolonisation of shrimps, other invertebrates and fry (small fish) downstream of where the pollution entered the river.

Future restoration of the River Crane

Recently, we have carried out a number of surveys of the river. The data we have gathered will help shape the proposed actions in our restoration programme. We also hope that the programme will include ideas from local people and members of The Crane Valley Partnership. The Crane Valley Partnership includes expertise from organisations such as the London Wildlife Trust.

This partnership has a proven track record of delivering environmental projects that have improved the river over a number of years. We see the partnership taking on the crucial role of prioritising the work that will help bring about the recovery of the river. We have drafted a four year fish restocking strategy and are starting the first phase of restocking this December. We will be using fish from our Calverton Fish Farm, including 1,500 Chub, 1,500 Dace, 1,500 Roach and 1,000 Barbel (at a cost of around £5000). These fish will be released throughout the affected reaches of the river.

Small fish are stocked in larger numbers so the fish populations can shoal and spread out throughout the affected stretches. Over the years to come, a new fish population will eventually develop. The fish restocking strategy forms part of our vision for the river. We hope it evolves further as we continue to work in collaboration with the Crane Valley Partnership and local communities. The species we have selected to release are representative of those lost as a result of the incident. However, we do not have all the original species available at our fish farm. We have therefore selected those species that are available, were originally present in the river and are suitable for restocking. We will, however, check for other potential sources of fish. We have specifically chosen to release the fish in winter as the low temperatures and high levels of oxygen in the river make the process less stressful for the fish, increasing their chance of survival. In addition, there are lower numbers of naturally occurring parasites and pathogens, posing less of a threat to the fish as they adjust to their new environment.

What happens next?

Once we have completed our investigation, we will present the results to our legal department. They will then decide what enforcement action should be taken. We want to ensure the River Crane is restored, as far as possible, to the condition it was in before the incident, and that polluters are held accountable where an offence has been committed. By continuing to work closely with The Crane Valley Partnership and other local groups, we will make the best use of available resources and will get the best result for the environment. It is our continued aspiration that in further years the condition of the river is better than it was before the pollution incident.