Q7. Dam failures are always catastrophic, especially on the downstream side, resulting in a colossal loss of life and property. Analyse the various causes of dam failures. Give two examples of large dam failures. (10m) – Environment & DM
Introduction
Dam failure refers to the catastrophic or unexpected breach of a dam structure which may stem from diverse natural and anthropogenic causes. The impacts of dam failure can be severe and far-reaching, affecting both human lives, infrastructure and the environment.
Body
Causes of Dam Failures
- Natural disasters: Heavy rainfall (Tiware dam in Ratnagiri, Maharashtra, 2019), earthquakes (e.g. Koyna Dam failure, 1967) and landslides.
- Design and construction flaws: (e.g. Karam dam in Madhya Pradesh, 2022)
- Ageing infrastructure: Lack of regular inspections, maintenance, and repairs ( Pulichintala Irrigation Project on Krishna River, Andhra Pradesh, 2021)
- Foundation problems: Weak or unstable foundation soils beneath the dam
- Seepage and internal erosion
- Over-topping: When water rises above the crest of the dam
- Operational failures: Improper operation of the dam, including inadequate release of water during periods of high inflow or failure to adjust for changing conditions.
Examples of Large Dam Failures
downstream
- The Machhu Dam Failure ( 1979): Located in Morbi, Gujarat, India, the dam failed on due to excessive rainfall. The sudden release of water led to devastating floods that resulted in the loss of 2000 lives and extensive damage to infrastructure. It is considered one of the worst dam failures in India.
- Banqiao Dam failure (1975): Located in China, the dam collapsed under the influence of Typhoon Nina affected 10.15 million and inundated around 30 cities.
Conclusion
Proactive measures, such as robust maintenance, monitoring, and community preparedness, are imperative to prevent catastrophic dam failures and safeguard lives and property. India’s Dam Safety Act, 2021 and Dam Safety Rehabilitation and Improvement Project (DRIP) are steps in the right direction.
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