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3 Examples of Recent Catastrophic Hydro-Dam Accidents
Fig. 3.1 Erosion of a large area of concrete and underlying rock in the main Oroville Dam spillway.
Photo Dale Kolke/California Department of Water Resources
behind the dam had stabilized, the authorities downgraded the order to an evacuation
warning and gradually allowed residents to return to their homes.
While the main embankment dam did not fail, its integrity was significantly threatened, as indicated by the decision to evacuate 180,000 people, which would not have
been taken lightly. The consequences of 4400 million cubic metres of water being
released are hard to imagine. Referring to the spillway problems as an incident does
not properly express the seriousness of what happened and the need to use it as a
learning opportunity.
In response to this incident, the Federal Energy Regulatory Commission required
the DWR to engage an Independent Forensic Team (IFT) to develop findings and
opinions on the causes of the incident. Two leading dam engineering and dam safety
associations in the United States were asked by DWR to recommend a team of six
members, all of whom were accepted DWR and subsequently engaged. The terms
of reference adopted by the IFT are as follows:
To complete a thorough review of available information to develop findings and opinions on
the chain of conditions, actions, and inactions that caused the damage to the service spillway
and emergency spillway, and why opportunities for intervention in the chain of conditions,
actions, or inactions may not have been realized. Evaluations of actions, inactions, and
decisions for the various stages of the project (pre-design, design, construction, operations,
and maintenance) will consider the states of practice applicable to the various time periods
involved.
3 Examples of Recent Catastrophic Hydro-Dam Accidents
Fig. 3.1 Erosion of a large area of concrete and underlying rock in the main Oroville Dam spillway.
Photo Dale Kolke/California Department of Water Resources
behind the dam had stabilized, the authorities downgraded the order to an evacuation
warning and gradually allowed residents to return to their homes.
While the main embankment dam did not fail, its integrity was significantly threatened, as indicated by the decision to evacuate 180,000 people, which would not have
been taken lightly. The consequences of 4400 million cubic metres of water being
released are hard to imagine. Referring to the spillway problems as an incident does
not properly express the seriousness of what happened and the need to use it as a
learning opportunity.
In response to this incident, the Federal Energy Regulatory Commission required
the DWR to engage an Independent Forensic Team (IFT) to develop findings and
opinions on the causes of the incident. Two leading dam engineering and dam safety
associations in the United States were asked by DWR to recommend a team of six
members, all of whom were accepted DWR and subsequently engaged. The terms
of reference adopted by the IFT are as follows:
To complete a thorough review of available information to develop findings and opinions on
the chain of conditions, actions, and inactions that caused the damage to the service spillway
and emergency spillway, and why opportunities for intervention in the chain of conditions,
actions, or inactions may not have been realized. Evaluations of actions, inactions, and
decisions for the various stages of the project (pre-design, design, construction, operations,
and maintenance) will consider the states of practice applicable to the various time periods
involved.