Leakage from small raised reservoir
Publish date
02 September 2025
Case ID#
3261
Title
Leakage from small raised reservoir
Nation
England
Regulator reference no.
523
Legal status
Non-statutory
Reservoir type
Impounding
Reservoir capacity
10M+ m3
Year of construction
Unknown
Main construction type
Unknown
Dam height
5 - 9.99 metres
Dam flood category
Other / Not applicable
Hazard class
Undesignated / Unclassified
Reservoir use
- Other
Owner type
Unknown
Date & Time of incident
09 December 2024 - 12:00
Date incident closed
Observations that caused the incident to be declared
- Leakage or seepage from a new leakage point
Describe the incident
This incident occurred at an unregistered SRR. An operative from an undertaker of a nearby LRR noticed water from the SRR running through a wall and over the towpath into a canal. There was also significant leakage through an embankment and into the river. The operative contacted the Environment Agency incident team. Local Environment Agency staff attended site and confirmed the wall was bulging and leaking. As this site was unregistered, there was no knowledge of design, maintenance or any surveillance. Attempts to contact a potential landowner were unsuccessful.
Supporting photos
Natural processes which initiated or contributed to the incident
What were the main contributing factors to the incident occurring?
Dam factors
- Deterioration of materials
- Instability
External factors
- None
Shortcomings
- Design shortcoming
- Maintenance shortcoming
- Surveillance shortcoming
What was the root cause of the incident?
Impacts on the reservoir
- Internal erosion (adjacent to structures)
- Settlement / deformation (outside normal or expected parameters)
Supporting photos
Describe any human factors which influenced the incident
Describe any instrumentation at the reservoir and how this was used in warning of the incident or providing monitoring during the incident
Was instrumentation effective leading up to and during the incident?
Not Applicable
Describe any assistance by external parties and impacts on the downstream population
None
Summary of studies or investigations undertaken
Supporting photos
Lesson 1
- Operation and maintenance
SRR can pose risks to local infrastructure and the public. Although not required by law, they should be maintained appropriately to reduce risks of failure.
Lesson 2
- Records and studies
If the SRR were to fail, there may be impacts on a nearby LRR. Owners of LRR should be aware of hazards surrounding their site so that they can mitigate the risk.