Thirsty farms, slowing turbines: how depleting dams threaten power, harvest

Scanty rains of the southwest monsoon have left India’s key reservoirs severely depleted, threatening irrigation, agricultural output and hydropower generation. Reservoirs that were over 90% full last year are now not even two-thirds full, official data showed, following one of the driest monsoon seasons in decades.

Water levels at India’s 178 reservoirs supplying irrigation canals, hydropower units and municipal drinking water are down 27% from a year ago to 121.9 billion cubic metres (bcm), official data showed. The dry spell is already rippling through the rural economy, where six states have declared drought, rabi crop sowing has dropped, and the Reserve Bank of India has warned of mounting risks to food inflation.

Apart from the central region where levels were marginally above last year’s, storage was lower in all other regions, data from the Central Water Commission showed.

The water scarcity was worst in the southern region, where reservoirs are only 42.6% full (against last year’s 89.97%), compared with north having 56.62% (86.32%), west 76.17% (96.10%), east 75.74% (81.66%) and central 84.23% (92.01%). While the southwest monsoon that brings most of India’s rains has concluded, the northeast monsoon remains active in the southern peninsula, raising hopes of further rains in catchment areas.

Farm trouble

Not surprisingly, sowing has slipped. Crops were sown across 11.7 million hectares till 6 November, 2.43 million hectares below last year’s 14.1 million at this time. To be sure, rabi sowing is still on, and typically continues till end of December. India’s average rabi acreage in the FY21 to FY25 period was 70.1 million hectares.

Less water for irrigation may impact sowing and harvest, experts pointed out.

“Low reservoir levels, particularly in the western and southern regions, could affect rabi crop cultivation, as farmers in these areas depend heavily on reservoir water for irrigation. Crops such as wheat, paddy, pulses and oilseeds could face irrigation constraints if water availability remains limited during critical growth stages,” said Sudhir Panwar, a farm policy expert and former member of Uttar Pradesh Planning Commission.

Wheat acreage has slipped 12% to 1.97 million hectares, rice 3.10% to 673,000 hectares, and pulses 14.4% to 3.2 million hectares, agriculture ministry data showed.

However, some said the impact will be limited in the northwestern region.

“The impact of lower reservoir levels on rabi crops is likely to be negligible in northwestern India, as the region is well-irrigated. Moreover, wheat, a major rabi crop in the region, requires relatively less water and all the growing areas are irrigated. The impact is likely to be concentrated in areas where farmers depend heavily on reservoir water for irrigation,” said AK Singh, former director, Indian Agricultural Research Institute (ICAR).

The World Meteorological Organization (WMO) warned in September that the 2026 El Niño could be unprecedented in strength, potentially taking Pacific Ocean temperatures 3.8°C above average, with its peak expected towards the end of 2026 and climate impacts extending well into 2027. For India, it means below-normal rainfall, higher temperatures and prolonged drought conditions. India’s southwest monsoon rainfall in 2026 stood at 87% of the 50-year average, making it the fourth-lowest since 2001 and the 13th-lowest since 1901, according to the India Meteorological Department (IMD). October rainfall saw a deficit of 31.4%.

In late October, Maharashtra expanded drought relief to 305 of the state’s 358 talukas and approved a ₹7,500-crore package, including ₹5,000 aid for eligible farmers.

Power pangs

While coal dominates India’s power sector, hydropower plays a critical role in supporting solar and wind power. Turbines can be quickly turned on and off; so, hydropower can step in or dial down when the sun doesn’t shine and the wind doesn’t blow.

“In the case of run-of-the-river hydro projects, the lesser discharge of water may impact hydropower generation and the decline in reservoir levels would also bring hydro power generation below what is generally witnessed during these months,” said Raj Kumar Chaudhary, former chairman and managing director, NHPC Ltd.

India has 20 reservoir-based hydropower projects, monitored by the CWC. Gobind Sagar dam in Himachal Pradesh, with a generation capacity of 1.3GW as of 5 November had storage of 56.87% of the full reservoir level (FRL), compared to 85.09% in the corresponding period last year. It is also way below its 10-year average of 73.52%. Similarly, the reservoir level in the Koyna dam (1.9GW) in Maharashtra is currently at 87.67% of the full reservoir level, while last year it stood at 100%. The current level in Tehri dam (1GW) in Uttarakhand is 92.91%, compared to 95.28% last year.

Chaudhary added that heating demand may add to overall consumption. The former NHPC chief noted that although solar and thermal would play a key role in these winter months, pollution and heavy smog in northern states could impact solar power generation in the region, affecting overall power supply.

“Thermal power generation is expected to be adequate, and in states like Rajasthan, solar power generation should help. But in Delhi-NCR and neighbouring areas, instances of pollution, smog and cloud cover may reduce solar power generation. That may hit overall solar generation,” he said.

This year, India witnessed a record power demand of 270.8GW in May, and instances of shortfall during peak demand hours also reached multi-year highs of 30 million units a day in September. Experts suggested that despite the fall in decline, such high shortfalls may not be seen in the winters.

Queries mailed to the ministry of jal shakti, power, NHPC and SJVN remained unanswered till the press time.