Ageing Dams in India
Kartavya Desk Staff
Syllabus: Infrastructure
Source: TH
Context: India faces an ageing dam challenge — over 1,065 dams are 50–100 years old and 224 are 100+ years old (2023 data).
• Experts warn that many dams are nearing the end of their design life, raising safety, irrigation, and hydropower
About Ageing Dams in India:
History of Dams in India:
• Pre-Independence: Kallanai (2nd century CE) is one of the world’s oldest functioning dams, built for irrigation; Mettur (1934) and Nizam Sagar (1931) were among the earliest large modern reservoirs.
• Colonial Era: British built Krishna and Godavari anicuts to boost canal irrigation; conceptualised Damodar Valley Corporation on the Tennessee Valley model.
• Post-Independence Era: Bhakra-Nangal (1963), Hirakud (1957), Rihand, Tungabhadra and Koyna dams symbolised Nehru’s “temples of modern India,” fueling Green Revolution.
• 1951–1971 Expansion: India started work on 418 large dams in two decades, marking a massive nation-building push for irrigation, power, and flood control.
• Modern Era: Shift to multipurpose projects integrating irrigation, power, tourism, navigation, and inland fisheries for holistic water resource development.
• Current Phase: Focus on rehabilitation, modernization, and climate resilience to extend lifespan and ensure safety of ageing infrastructure.
Laws & Policies for Dams in India:
• Dam Safety Act, 2021: Provides a legal framework for dam surveillance, operation, and maintenance; establishes NDSA, National Committee on Dam Safety, and State Dam Safety Organisations (SDSOs).
• Mandatory Inspections: Requires pre- and post-monsoon inspections, Emergency Action Plans, and inundation maps to prevent disasters and ensure preparedness.
• Dam Rehabilitation and Improvement Project (DRIP I–III): Covers 736 dams across 19 States with World Bank & AIIB funding for structural strengthening, gate replacement, monitoring equipment, and staff training.
• Central Water Commission (CWC) Guidelines: Issue technical protocols for periodic safety reviews, risk assessment, and remedial action to maintain dam health.
• No Formal Decommissioning Policy: India currently focuses on extending lifespan; lacks a structured framework to safely retire obsolete or unsafe dams.
Challenges to Dams in India:
• Ageing Infrastructure: Over 4,200 dams will cross the 50-year mark by 2050, raising risks of structural fatigue and safety lapses. Old spillway designs are inadequate to handle present-day floods, increasing overtopping risk.
• Over 4,200 dams will cross the 50-year mark by 2050, raising risks of structural fatigue and safety lapses.
• Old spillway designs are inadequate to handle present-day floods, increasing overtopping risk.
• Sedimentation & Loss of Capacity: Bhakra, Hirakud, and Lower Bhavani lost 20–30% storage due to siltation. Reduced live storage hits irrigation potential, hydro generation, and drinking water supply.
• Bhakra, Hirakud, and Lower Bhavani lost 20–30% storage due to siltation.
• Reduced live storage hits irrigation potential, hydro generation, and drinking water supply.
• Climate Change & Extreme Events: Cloudbursts, GLOFs (Sikkim 2023), and intense monsoons strain ageing dams. Flood routing capacities often lag behind probable maximum flood estimates.
• Cloudbursts, GLOFs (Sikkim 2023), and intense monsoons strain ageing dams.
• Flood routing capacities often lag behind probable maximum flood estimates.
• Seismic & Geotechnical Risks: Dams like Mullaperiyar & Koyna lie in seismically active zones; cracks & seepage are recurring concerns. Foundation erosion and piping threaten earth-fill dams’ stability.
• Dams like Mullaperiyar & Koyna lie in seismically active zones; cracks & seepage are recurring concerns.
• Foundation erosion and piping threaten earth-fill dams’ stability.
• Institutional & Governance Gaps: Inadequate data transparency and limited citizen participation. Absence of decommissioning policy and slow implementation of rehabilitation projects.
• Inadequate data transparency and limited citizen participation.
• Absence of decommissioning policy and slow implementation of rehabilitation projects.
Case Studies:
• Mullaperiyar Dam (1895): 120+ years old, inter-state safety dispute between Kerala & TN, seismic vulnerability flagged by experts.
• Hirakud Dam (1957): Lost 25% capacity and near-overtopping in 1982 prompted auxiliary spillway creation.
• Bhakra Nangal (1963): Sedimentation reduced reservoir capacity by 23%; seismic reanalysis underway.
• Tiware Dam Failure (2019): Breach killed 19 people and highlighted need for robust inspection regime.
Way Forward:
• Risk-Based Prioritisation Focus on high-consequence dams first (downstream population, economic value). Independent third-party safety audits.
• Focus on high-consequence dams first (downstream population, economic value).
• Independent third-party safety audits.
• Strengthening Infrastructure Retrofit spillways, reinforce structures per latest seismic & climate standards. Catchment area treatment to slow silt inflow.
• Retrofit spillways, reinforce structures per latest seismic & climate standards.
• Catchment area treatment to slow silt inflow.
• Decommissioning & Repurposing Develop formal policy for safe decommissioning when risk > benefit. Explore alternate water storage systems (aquifer recharge, check dams).
• Develop formal policy for safe decommissioning when risk > benefit.
• Explore alternate water storage systems (aquifer recharge, check dams).
• Community Engagement & Transparency Downstream hazard mapping, public warning systems, mock drills. Open-access dam safety database for citizen oversight.
• Downstream hazard mapping, public warning systems, mock drills.
• Open-access dam safety database for citizen oversight.
• Climate-Resilient Design Incorporate probable maximum flood (PMF), GLOF risk, glacial retreat modelling in dam management plans.
• Incorporate probable maximum flood (PMF), GLOF risk, glacial retreat modelling in dam management plans.
Conclusion:
India’s dams are both lifelines and liabilities as they age. A science-based, risk-informed, and climate-resilient approach to dam management is vital. Long-term sustainability lies not just in preserving dams, but in prioritizing safety, minimizing risks, and ensuring intergenerational water security.