Major Causes of Dam Failure Incident

Here is a list of some causes of dam failure incidents that occurred between 2000 and 2019:

  1. Poor Design and Construction: Deficiencies in the design and construction process can lead to dam failures. Factors such as inadequate engineering, improper materials, or substandard construction techniques can compromise the structural integrity of the dam.
  2. Severe Weather Events: Extreme weather conditions, including heavy rainfall, hurricanes, or cyclones, can exert significant pressure on dams. Excessive inflow of water, especially when combined with inadequate spillway capacity or poor flood management, can result in dam failures.
  3. Foundation Problems: Dam failures can occur when there are issues with the foundation upon which the dam is built. Weak soil conditions, improper soil compaction, or geological instability can undermine the stability of the dam and lead to failure.
  4. Overtopping: When water levels exceed the capacity of a dam’s spillway, overtopping can occur. If the spillway is insufficient or blocked, the excess water can flow over the dam, erode the embankment, and eventually cause a breach or failure.
  5. Piping and Internal Erosion: Piping refers to the process by which water seeps through the dam or its foundation, creating internal erosion. If not detected and addressed, piping can weaken the structure over time, potentially leading to dam failure.
  6. Insufficient Maintenance and Aging Infrastructure: Lack of regular inspection, maintenance, and rehabilitation of dams can contribute to their deterioration over time. Aging infrastructure, including the degradation of concrete or corrosion of metal components, can weaken the dam’s integrity and increase the risk of failure.
  7. Human Error and Mismanagement: Human factors, such as errors in operation, poor decision-making, inadequate emergency response, or lack of adherence to safety protocols, can contribute to dam failures.
  8. Natural Disasters: Beyond severe weather events, other natural disasters like earthquakes or landslides can trigger dam failures. The shaking or displacement caused by earthquakes or the destabilization of the surrounding environment due to landslides can compromise the integrity of the dam.
  9. Terrorism or Sabotage: Although relatively rare, intentional acts of terrorism or sabotage can result in dam failures. Deliberate damage or tampering with critical components can lead to catastrophic consequences.

It is important to note that this list is not exhaustive, and the specific causes of dam failure incidents can vary depending on the circumstances of each case. Additionally, advancements in engineering and risk management practices continue to improve dam safety and mitigate the likelihood of failures.

Overtopping is the No. 1 cause of dam failure

Here are few examples of significant dam failures caused by overtopping incidents:

  1. Banqiao Dam Failure (China, 1975):
    The Banqiao Dam failure is considered one of the deadliest dam failures in history. In August 1975, Typhoon Nina struck Henan Province in China, causing heavy rainfall and triggering widespread flooding. The Banqiao Dam and its subsidiary dams faced intense inflows of water, overwhelming their capacity. The dams were unable to release water effectively, leading to overtopping and subsequent catastrophic dam failures. The resulting floods caused the loss of an estimated 171,000 lives, with millions more affected.
  2. Machhu Dam Failure (India, 1979):
    In August 1979, heavy rainfall in the state of Gujarat, India, led to the failure of the Machhu Dam. The dam’s spillway was inadequate to handle the excessive inflows, resulting in overtopping and subsequent erosion of the dam. The failure of the dam unleashed a massive wave of water that devastated the town of Morbi and surrounding areas. The tragedy claimed the lives of thousands of people.
  3. Malpasset Dam Failure (France, 1959):
    The Malpasset Dam failure occurred in December 1959 near Fréjus, France. The dam experienced heavy rainfall, causing increased water levels in the reservoir. The dam’s inadequate spillway design and construction led to overtopping and subsequent failure. The released water surged downstream, causing significant damage and resulting in the loss of more than 400 lives.
  4. Vajont Dam Failure (Italy, 1963):
    The Vajont Dam failure is another notable incident caused by overtopping. In October 1963, a massive landslide occurred near the newly constructed Vajont Dam in northern Italy, causing a large volume of rock and debris to fall into the reservoir. The displacement of water from the landslide triggered a massive wave that overtopped the dam, resulting in catastrophic flooding. The disaster claimed the lives of approximately 2,000 people.

These examples highlight the devastating consequences of dam failures caused by overtopping incidents. It’s important to note that lessons learned from these incidents have led to advancements in dam design, construction, and safety practices to mitigate the risks associated with overtopping and improve the overall safety of dams worldwide.