Dam failures are always catastrophic, especially on the downstream side, resulting in a colossal loss of life and property. Analyze the various causes of darn failures. Give two examples of large dam failures. (150 words) (UPSC GS 3 2023/10 marks)

Introduction

Dam failures are relatively rare events. Throughout history, there have been numerous dam failures that have resulted in significant loss of life and property.

Causes of Dam Failures:

1. Poor Design and Construction:

   - Inadequate engineering design or construction methods can lead to weak dams that are prone to failure.

   - Factors like improper materials, foundation issues, or insufficient spillways can contribute.

2. Hydraulic Failures:

   - Over-topping: When a dam is unable to handle excess water flow during heavy rain or flooding, it can lead to over-topping and eventual failure.

   - Erosion: Water erosion can weaken the dam's structure and erode its foundation.

3. Structural Deficiencies:

   - Aging Infrastructure: Older dams may deteriorate over time, leading to structural weaknesses.

   - Lack of Maintenance: Poor maintenance practices can result in undetected issues that worsen over time.

4. Foundation Problems:

   - Settlement: Uneven settlement of the dam's foundation can lead to structural stress and potential failure.

   - Seepage: Excessive seepage of water through the foundation can erode the soil and weaken the dam's base.

5. Natural Disasters:

   - Earthquakes: Seismic activity can induce dam failures, especially in regions prone to earthquakes.

   - Landslides: Dam failures can occur when landslides impact the dam structure or block drainage channels.

6. Human Error:

   - Operational Mistakes: Errors in dam operation, such as improper release of water or failure to respond to changing conditions, can lead to failure.

- Inadequate Monitoring: Neglecting regular inspections and monitoring can result in undetected issues.

7. Climate Change and Extreme Weather: Increasingly extreme weather events, such as heavy rainfall and prolonged droughts, can strain dam infrastructure and contribute to failures.

8. Sabotage and Terrorism: Deliberate acts of sabotage or terrorism can compromise dam integrity and lead to catastrophic failures.

9. Inadequate Emergency Response: Poorly planned or executed emergency response measures can exacerbate the consequences of a dam failure.

10. Siltation and Sedimentation: Accumulation of silt and sediment in reservoirs can reduce a dam's storage capacity and affect its overall stability.

Two Examples of Large Dam Failures:

1. Libya Dam Collapse (2023):

   - Eastern Libya experienced devastating flooding triggered by heavy rains from Mediterranean storm Daniel.

   - Two dams were overwhelmed by the deluge, unleashing a towering wall of water that surged through Derna's heart, causing widespread destruction to entire neighborhoods and sweeping individuals out to sea.

2. Banqiao Dam, China (1975):

   - The Banqiao Dam failure stands as one of the most lethal dam collapses in history.

   - This tragic event unfolded during a typhoon, with the dam proving unable to manage the excessive rainfall. The ensuing catastrophe resulted in catastrophic flooding, leading to the loss of an estimated 26,000 lives and affecting millions more.

Conclusion

Understanding the causes of dam failures is crucial for improving dam safety measures, designing resilient structures, and preventing catastrophic incidents in the future.