Volunteers clear 250 tonnes of floating pennywort from the Lee Navigation

Paddle UK has reported the latest results of its River Lea Floating Pennywort Project, which ran a series of community clean-up sessions along the Lee Navigation over the summer of 2026. Floating pennywort is an invasive non-native species (INNS) that forms dense mats across the surface, smothering habitat, slowing the flow and stripping oxygen from the water — and making stretches of the navigation hard to paddle or sail through.

What happened

• Paddle UK led the project with the Canal & River Trust, Angling Trust, Environment Agency, the Leaside Trust and Thames Water.
• Volunteers were joined by teams from Coca-Cola, the Animal and Plant Health Agency, the Camping and Caravanning Club and Whoosh Canoes, with instructors from the Leaside Trust on the water.
• Across 2025–26 the project has cleared 22.5km of waterway and taken out 250 tonnes of the plant; more than 600 volunteers from 30 community groups gave 6,800 hours in the past year.
• Work this year included Mossop's Creek, a tributary near Enfield, which was mechanically cleared in December 2025 but has already grown back substantially.
• In warm weather the plant can put on 20cm a day, and even small fragments will root and spread.

Why it matters

• Clearance is temporary: regrowth at Mossop's Creek shows why repeat sessions are needed on any affected water.
• Boats, boards and kit move fragments between sites, so Paddle UK asks everyone leaving the water to Check, Clean, Dry — remove mud and plant material, wash kit in hot water, then dry it for as long as possible.
• Clubs on the Lea can volunteer for future sessions through Paddle UK's environment team.

Source: Volunteers tackle floating pennywort on the Lee Navigation, Paddle UK, 19 October 2026. Summary by Pushing the Boat Out.