India's reservoirs are 31% below full capacity post-monsoon, with southern states facing acute water shortages.
Major reservoirs like Aliyar, Somasila, and Mettur report critically low levels, raising concerns over irrigation, drinking water, and hydropower.
Regional disparities highlight severe deficits in Pennar and Cauvery basins, while Narmada and Mahanadi basins show surplus storage.
Monsoon 2026 has ended, but many of India's reservoirs have not filled to capacity. Across the country's 178 major reservoirs, water storage remains about 31 per cent below full capacity, raising concerns over water availability in the coming months.
According to the Central Water Commission's (CWC) Reservoir Storage Bulletin released on Thursday, 15 October 2026, the 178 reservoirs held 126.717 billion cubic metres (BCM) of water, representing 68.58 per cent of their total usable storage capacity. This means that 31.42 per cent of their combined capacity remained unfilled.
The bulletin showed that water storage was 41.193 BCM, or 24.53 per cent, lower than during the same period last year. It was also 24.930 BCM, or 16.44 per cent, below normal levels, calculated using the average storage recorded over the past 10 years.
The CWC monitors water levels in 178 major reservoirs across India and publishes a weekly bulletin every Thursday. Together, these reservoirs have a usable storage capacity of 184.762 BCM, accounting for about 71.67 per cent of the country's total usable reservoir storage capacity of 257.812 BCM.
Reservoir levels fall sharply in southern and western states
Water levels in several major reservoirs have fallen to less than half their normal storage levels. Data from the bulletin showed particularly severe shortages in reservoirs across Andhra Pradesh, Karnataka, Maharashtra, Tamil Nadu and Telangana.
The Aliyar reservoir in Tamil Nadu, recorded no water storage relative to its normal level, placing it at the bottom of the list of reservoirs with less than 50 per cent of normal storage.
In Andhra Pradesh, the Somasila reservoir held 22.05 per cent of its normal storage, while Srisailam stood at 33.64 per cent. Tamil Nadu's Mettur reservoir had 32.49 per cent of normal storage, while Kerala's Idukki reservoir had just 10.62 per cent.
Several reservoirs in Maharashtra also recorded substantial deficits. Jaikwadi held 15.55 per cent of normal storage, Ujani 10.62 per cent, Manjra 12.45 per cent and Lower Terna 28.24 per cent.
In Karnataka, Ghataprabha, Tungabhadra and Sholayar recorded 22.56 per cent, 22.54 per cent and 23.62 per cent of normal storage, respectively. Kerala's Periyar reservoir held 46.43 per cent of its normal storage.
The figures indicate that water availability in several reservoirs across southern and western India remains well below normal levels.
The bulletin also identified 42 reservoirs with water storage between 50 per cent and 80 per cent of normal levels. Of these, 11 had between 51 per cent and 60 per cent of normal storage, 14 had between 61 per cent and 70 per cent, and 17 had between 71 per cent and 80 per cent.
Meanwhile, 12 of the 20 reservoirs associated with hydropower projects had storage levels at or below normal, raising concerns over potential effects on irrigation, drinking water supplies and electricity generation.
Pennar and Cauvery basins face severe deficits
A river basin-wise assessment showed that water storage in the Pennar and Cauvery basins fell into the highly deficient category.
The Indus, Mahi, Krishna and Sabarmati basins, along with the Kutch-Saurashtra and Luni river regions, were classified as deficient. Water shortages were also recorded in the east-flowing river basins between Pennar and Kanyakumari and the west-flowing basins between Tadri and Kanyakumari.
In contrast, water storage in the Narmada, Mahanadi and Swarnarekha basins was above normal.
Several other river basins, including the Ganga, Tapti, Godavari, Brahmaputra and Brahmani-Baitarani, had storage levels close to normal.
The figures highlight significant regional differences in India's reservoir storage, with particularly large deficits in southern river basins.
The Cauvery basin recorded a 60.50 per cent deficit compared with normal storage, while the Pennar basin had a deficit of 72.32 per cent. The Krishna basin recorded a 32.59 per cent deficit and the Sabarmati basin a 38.03 per cent deficit.
By comparison, water storage in the Narmada basin was 7.81 per cent above normal. The Mahanadi basin recorded a surplus of 2.95 per cent, while the Swarnarekha basin had 30.74 per cent more water than normal.