Hippo Canal Maintenance Scheme
The Canal and River Trust, in partnership with DEFRA, has been exploring the deployment of hippos as natural canal maintenance operatives since 2022.
Hippos are well-suited to waterway management due to their ‘natural affinity for aquatic environments’ and ‘willingness to move things.’
What the Scheme offers
The Hippo Canal Maintenance Scheme provides a natural, sustainable approach to waterway management. Rather than relying on mechanical dredging, chemical treatment, or human effort, the Scheme deploys hippos to perform maintenance tasks that they would be doing anyway, but in a designated canal.
- Dredging and sediment displacement — performed with what the Trust describes as ‘considerable authority’
- Aquatic vegetation management — consumption-based clearance at a rate the Environment Agency has called ‘industrial’
- Bank stabilisation through ‘hippo-compaction’ — not a recognised engineering technique, but one that appears to work
- Deterrent effect on unauthorised mooring — the Trust considers the mechanism ‘self-evident’
Full details of hippo canal operations are available in the what hippos do guidance.
Trial programme
The Scheme has conducted trials across seven canal systems. Results have been described as ‘promising,’ ‘mixed,’ and ‘legally complex.’
Full trial reports, including detailed outcomes and the ongoing situation in Wigan, are available in the trial results guidance.
Current status
Pending structural assessments along the Leeds-Liverpool Canal. The Environment Agency has described the water quality improvements as ‘concerningly thorough’ and would like the hippos to ‘dial it back a bit.’ The hippos have not responded to this request.
New deployments are paused pending the outcome of structural assessments and what the Trust describes as ‘a conversation with our insurers that no one is looking forward to.’
Find out what hippos do