Series of SRR weirs came close to breaching in flood event

Basic details

Publish date

02 September 2025

Case ID#

3120

Title

Series of SRR weirs came close to breaching in flood event

Nation

England

Regulator reference no.

310

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

Incident details

Date & Time of incident

02 July 2007 - 12:00

Date incident closed

Observations that caused the incident to be declared

  • Slope or face deformation (slippage, cracking, slumps, mounds, depressions)
  • Deformation or instability of crest (settlement, cracking, depressions)

Describe the incident

A series of weirs, already in a poor condition, were damaged during a flood event. One weir in particular, about 1.5m high and impounding about 12,000m3 , came close to breaching due to erosion around an abutment. It was not possible to access the sluice gate to lower the water level until the flood subsided

Supporting photos

Causes and impacts

Natural processes which initiated or contributed to the incident

  • Flood - within dam design capability

What were the main contributing factors to the incident occurring?

Dam factors

  • Deterioration of materials

External factors

  • None

Shortcomings

  • Surveillance shortcoming
  • Maintenance shortcoming

What was the root cause of the incident?

Impacts on the reservoir

  • External erosion

Supporting photos

Supporting contributions and studies

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

Unknown

What are the lessons learnt from the incident

Lesson 1

  • Records and studies
  • Surveillance and Monitoring
All tunnels under dams should be regularly inspected and any information on the design and inspection of these tunnels should be kept with the reservoir records.

Closing comments

Supporting photos