What Happened
- Water storage in India's key reservoirs has dropped significantly, with the southern region slipping below 50% of capacity
- Over 70% of the country received deficient rainfall since the beginning of the year (January-February 2026)
- As of March 5, 2026, the 166 monitored reservoirs held only 56.73% of total live storage capacity, declining further in subsequent weeks
- Southern reservoirs are the worst affected, raising concerns over summer water availability for irrigation and drinking water
- Several individual reservoirs have critically low levels: Sholayar (Tamil Nadu) at 31.58%, Vaigai (Tamil Nadu) at 38.16%
- The situation is expected to worsen as pre-monsoon temperatures rise and agricultural water demand increases
Static Topic Bridges
Central Water Commission (CWC) — Reservoir Monitoring System
The Central Water Commission (CWC) is a premier technical organisation in India in the field of water resources, functioning under the Ministry of Jal Shakti (Department of Water Resources, River Development and Ganga Rejuvenation). The CWC monitors the live storage status of 161 major reservoirs across the country on a weekly basis and publishes a weekly bulletin every Thursday.
- Established: 1945 (as Central Waterways, Irrigation and Navigation Commission); reorganised in 1946 as CWC
- Monitors 161 major reservoirs (expanded from earlier 150) across five regions: Northern, Eastern, Western, Central, and Southern
- Total live storage capacity of monitored reservoirs: 182.375 BCM (billion cubic metres), which is approximately 70.74% of total estimated live storage capacity created in the country
- The Web-based Reservoir Storage Monitoring System (RSMS) portal provides real-time data
- Weekly bulletins are sent to PMO, NITI Aayog, Ministry of Jal Shakti, Ministry of Power, Ministry of Agriculture, IMD, and disaster management authorities
- CWC also handles flood forecasting (operates 325+ flood forecasting stations) and interstate water dispute data
Connection to this news: The CWC's weekly reservoir bulletin is the authoritative source for the data cited in this report, and its regional breakdown (with the Southern Region below 50%) directly informs state-level water management decisions.
India's Monsoon Dependence and Rainfall Classification
India's agriculture and water resources are overwhelmingly dependent on the monsoon system. The India Meteorological Department (IMD) classifies rainfall departure from the Long Period Average (LPA) into five categories: Excess (above +20%), Normal (-19% to +19%), Deficient (-20% to -59%), Scanty (-60% to -99%), and No Rain (-100%).
- Southwest monsoon (June-September): contributes approximately 75% of India's annual rainfall
- Northeast monsoon (October-December): critical for Tamil Nadu, Andhra Pradesh coastal regions, and parts of Karnataka and Kerala
- Winter rainfall (January-March): driven by Western Disturbances; critical for rabi crops (wheat, mustard, gram) in North India
- The IMD uses 1971-2020 as the Long Period Average (LPA) baseline for classification
- El Nino years typically associated with deficient monsoon rainfall; La Nina with excess rainfall
- Over 70% of regions receiving deficient winter rainfall in 2026 is significant because winter rains replenish reservoirs used for summer irrigation and drinking water supply
- India's total water storage capacity: approximately 257 BCM across ~5,700+ dams (National Register of Large Dams)
Connection to this news: The 70% deficient rainfall figure since January 2026 falls in the "deficient" category under IMD classification, directly explaining why reservoir levels — especially in the rain-shadow and peninsular regions — are declining ahead of the summer season.
Inter-State River Water Disputes and Water Governance
India's federal structure creates challenges for water governance, as water is a State List subject (Entry 17, State List) while the Centre has regulatory power over inter-state rivers (Entry 56, Union List). The Inter-State River Water Disputes Act, 1956 (amended 2002) provides the legal framework for resolving disputes through tribunals.
- Constitutional basis: Article 262 — Parliament may provide for adjudication of inter-state water disputes; bars Supreme Court jurisdiction over such disputes
- Inter-State River Water Disputes Act, 1956: Centre constitutes ad hoc tribunals for specific disputes
- Major tribunals: Cauvery Water Disputes Tribunal (1990, final award 2018), Krishna Water Disputes Tribunal (I: 1969, II: 2004), Narmada Water Disputes Tribunal (1969, award 1979)
- National Water Policy: Latest version 2012 — prioritises drinking water, then irrigation, then hydropower, then industrial use
- Jal Jeevan Mission (2019): Aims to provide functional household tap connections to every rural household by 2024 (extended); flagship programme under Ministry of Jal Shakti
- Dam Safety Act, 2021: Provides for surveillance, inspection, operation, and maintenance of dams to prevent dam failure disasters
Connection to this news: Declining reservoir levels in the southern region intensify inter-state water tensions, particularly in the Cauvery (Karnataka vs Tamil Nadu) and Krishna (Andhra Pradesh vs Telangana vs Karnataka) basins, where summer allocations become contentious.
Key Facts & Data
- CWC monitors 161 major reservoirs with total live storage of 182.375 BCM (~70.74% of national capacity)
- As of March 5, 2026: overall storage at 56.73% of capacity; southern region below 50%
- Over 70% of India received deficient rainfall since January 2026
- Sholayar (Tamil Nadu): 31.58% storage; Vaigai (Tamil Nadu): 38.16% storage
- Southwest monsoon contributes approximately 75% of India's annual rainfall
- Water governance: State List subject (Entry 17) but Centre regulates inter-state rivers (Entry 56, Union List)
- Article 262: Parliament may adjudicate inter-state river disputes; bars Supreme Court jurisdiction
- India has approximately 5,700+ large dams with total storage capacity of ~257 BCM