Hydro reservoir levels hit lowest since 2023 as El Niño impact raises power generation concerns

According to the ministry, reservoir levels across the country remain lower than a year ago, with the sharpest decline recorded in the southern region. The energy content in reservoirs — representing the total electricity generation potential stored as water — has fallen 43% during April 1-July 30 compared with the corresponding period last year. It is also 39% lower than in 2024 and 17% lower than the same period in 2023, according to the data.

Southern India’s regional picture is particularly stark, where reservoir energy content is down 63% year-on-year. The decline stands at 25% in the north, 13% in western India, 28% in the eastern region and 22% in the north-eastern region.

Energy content in reservoirs

Source: Ministry of Power (Parliament answer)

The power ministry said it regularly monitors the country’s power supply situation and has “specifically reviewed” the likely impact of El Niño during the July-September 2026 quarter.

“Historically, El Niño events have been associated with significant temporal and spatial variations in monsoon rainfall, which can materially influence electricity demand, hydroelectric generation, renewable energy availability and overall power system reliability,’ it said.

“It has been assessed that electricity demand during monsoon season is expected to remain elevated owing to factors like sustained economic activity, agricultural irrigation requirements, and weather-related cooling loads,” the ministry added.

Reliance on coal

In our country’s power system, hydro power plays a key role in meeting evening peak demand during summer when solar output drops. However, rainfall deficit has altered the equation.

As hydro output weakened, India is relying more on coal-fired generation to bridge the gap. Coal-based power generation rose 9.49% year-on-year to 463,995.61 MU during April 1-July 30, 2026, from 423,764.78 MU a year earlier.

The reliance on thermal power was even more pronounced during July, with coal-fired generation rising 13.08% year-on-year to 111,095.89 MU during July 1-30, 2026.

Weak monsoon

The southwest monsoon, which lasts until September, has been affected by an intensifying El Niño, resulting in drier-than-normal conditions across large parts of the country.

Although rainfall improved in July after a significantly dry June, the recovery has been insufficient to erase the seasonal deficit, with cumulative rainfall still about 13% below normal. The weak monsoon has also kept electricity demand elevated for cooling and irrigation, pushing the country’s peak power demand to 270 gigawatts (GW) in July.

Meanwhile, India Meteorological Department (IMD) also predicts below normal rainfall from August to September. As per IMD, the country will receive under 94% of the normal rain expected for these months.

“During this period, below-normal rainfall is very likely over many parts of the country except some parts of the Peninsular India, Central India, northern parts of northwest India and East & Northeast India where normal to above-normal rainfall is likely,” IMD said in a statement on July 31.