Launch Recite Me web accessibility software

We work hard to stop the spread of invasive non-native species (INNS) which threaten our natural world.

Broadly speaking, non-native species are anything which didn't evolve in the UK, including well-loved species such as rabbits and horse chestnuts. But for something to be an invasive non-native species, it has to damage the economy or the environment. In addition to providing 520 million litres of water every day, we own or manage dozens of rare or protected habitats, including Sites of Special Scientific Interest, Areas of Outstanding Natural Beauty, National Parks and nature reserves.

Working alongside partners such as Natural England, the Angling Trust, British Canoe and local wildlife trusts, we carefully manage watercourses, reservoirs and other company-owned sites to protect them from the harm that invasive species can cause.

Some of the most common species we combat are:

  • Zebra mussels can clog the inside of water pipes and it has been estimated that the removal of this species alone costs the water industry more than £1 million per year.
  • Signal Crayfish carry a disease known as crayfish plague, which is 100% lethal to the native White-Clawed Crayfish if contracted.
  • Himalayan Balsam was introduced in the Victorian era as a garden plant but can now be found along riverbanks and ditches where it spreads quickly at the expense of native flowers.
  • Rhododendron was also introduced by the Victorians and today is usually found in woodland or heath land habitats. It spreads quickly, smothering rare or precious native plants, which some animals rely upon to survive.
  • Giant Hogweed has poisonous sap which can cause severe burns if affected skin comes into contact with sunlight.
Giant Hogweed c. NNSS

Innovative rust fungus trial to combat Himalayan Balsam

To stop the spread of Himalayan Balsam, a plant native to the Himalayas which is often found near rivers, we’ve teamed up with CABI Bioscience to trial the use of a rust fungus as a natural method of weakening the plant.

Protecting the wider environment and maintaining the quality of water in rivers, aquifers and reservoirs is our number one priority so we avoid using chemical herbicides wherever possible, in favour of natural control methods.

The trial involves infecting Himalayan Balsam with spores from a rust fungus which weakens the plant. We hope this will allow other, native, species to flourish.

Not only will this improve the biodiversity of the land but also reduce the effects of sedimentation in the rivers which we use to provide clean drinking water.

We began the trial in 2020 and hope to have initial results by the end of 2021.

Himalayan Balsam c. NNSS

Top tips to stop the spead of invasive species

There are three really simple yet important things that people can do to protect the environment from invasive species.

  1. Anyone using rivers, lakes or reservoirs for activities such as water sports and angling should follow the Check, Clean, Dry procedure. Simply put this means check your equipment and clothing for anything that may be attached, clean it with fresh water and a water-safe disinfectant, then leave it to dry.
  2. If you are in the countryside, we always ask people to leave the area as they found it - so don't be tempted to pick any flowers or plants as they may belong to an invasive species or even be dangerous.
  3. When choosing plants for your home or garden, or disposing of those you already have, ask your local garden centre for advice on all aspects of growing, managing and disposing of plants.