We love and care for your canals and rivers, because everyone deserves a place to escape.

Invasive species control

Our waterway network is home to many invasive species, which cause a variety of problems. From interfering with navigation and water control to reducing water quality and habitat availability, invasive species can have a huge impact on our canals and rivers.

Floating pennywork covering most of canal with boat moored at side Floating pennywort, copyright GBNNS

Non-native invasive species are considered the second greatest threat to native wildlife and they cost the UK economy as a whole up to £1.7 billion a year.

Every year we spend around £700,000 treating invasive weeds. However, these direct control costs are likely to represent a small proportion of the wider impact invasive species cause.

As non-native invasive species are often introduced to the waterway network by well-meaning members of the public, we have been working with Defra and the Non-Native Species Secretariat to raise awareness of the problems they cause.

If you’re concerned that an invasive species has not been dealt with on our waterways please get in touch with your [local office] and we’ll look into it.

The main offendersClose up of Japanese knotweed growing out of water

We’re fighting a brutal battle against Japanese knotweed. One of the most invasive weeds in Britain, Japanese Knotweed’s dense growth crowds out native vegetation, erodes riverbanks and causes structural damage.

We spray it twice a year to try and keep it under control. However, it’s impossible to eradicate it completely as it can grow from the smallest fragment of root.

Floating pennywort and water fern are also a problem for us as they can grow and spread rapidly, causing operational and safety concerns. It can cost up to £25,000 a year to treat a single infestation of floating pennywort.


What should I do if I spot invasive weeds by the canal?
As a responsible landowner we manage potentially damaging invasive plants such as giant hogweed and Japanese knotweed.

In the case of Japanese knotweed, if you believe that it is not being treated near you please contact us on 0303 040 4040 or let us know here.

What should I do if I spot ragwort on your land adjacent to horse grazing?
We comply with our duties in accordance with the responsibilities identified in the 1959 Weed Act, with regards to ragwort close to horse pasture. Contact us on  0303 040 4040 if you spot ragwort near a horse pasture.


Last date edited: 25 October 2016