Causes of Dam Failures
Natural Factors
Extreme Rainfall – Flooding causes 44% of dam failures in India (CWC). Eg- Tiware Dam breach in 2019
Chungthang Dam in Sikkim was washed away in 2023 due to glacial lake outburst of South Lhonak Lake.
Earthquakes cause cracks, foundation instability, or slope failure. Eg- liquefaction in the foundation of Chang Dam after Bhuj EQ (2001)
Geological Weaknesses – Fault zones, weak rock strata, or unconsolidated foundations beneath dams.
Climate Change – Increased frequency of high-intensity rainfall events beyond historical norms.
Human Factors
Faulty Design and Planning – Eg- Underestimation of Probable Maximum Flood (PMF).
Aging – 1,065 large dams 50-100 years old, 224 are over a century old. Eg- safety concerns over Mullaperiyar Dam (130 year old)
Weak Regulatory Oversight – Eg- poor dam safety audits (CAG report).
Poor maintenance and sedimentation – Eg- Around 3700 dams in India will lose 26% of the total storage by 2050 due to sedimentation (UN).
Examples of dam failures
Machhu dam disaster, 1979, in Morbi, Gujarat – 2,000 people died and 12,000 houses were destroyed.
Banqiao Dam Failure, China (1975)
Extreme rainfall from Typhoon Nina
Cascade failure of multiple dams due to poor design
Estimated 1,70,000 deaths (direct and indirect)
Initiatives Taken for Dam Safety in India
Dam Safety Act, 2021 – Statutory framework for surveillance, inspection, operation, and maintenance of dams.
National Register of Large Dams (NRLD) complied and maintained by CWC.
Dam Rehabilitation and Improvement Project (DRIP) for rehabilitation of 736 dams across 19 States.
Dam Health and Rehabilitation Monitoring Application (DHARMA)- application of Artificial Intelligence (AI) in dam safety.
Rigorous dam safety audits, climate-resilient design and real-time monitoring is essential to protect the ‘temples of modern India’