Dry Risk of Hydropower

Heavy reliance on hydropower may appear to be a sustainable and clean energy solution, but it comes with a hidden vulnerability — less water means less power, and that can mean blackouts. As climate patterns become increasingly unpredictable, overdependence on hydropower exposes nations to economic, environmental, social, and energy security risks.

Hydropower, often seen as a “sweet and sour” energy source, has trade-offs that can no longer be ignored. Scientists warn that changing weather patterns — prolonged heatwaves, droughts, and excessive rainfall — have revealed its fragility.

Since 2023, global temperatures have consistently remained above average. Regions such as Antarctica, Greenland, eastern North America, eastern Russia, Central and South America, and southern Australia have experienced record heat. The year 2023 was officially declared the hottest year on record, and the trend has continued — with 2024 and 2025 expected to break further records. The world has entered what experts describe as “uncharted territory” in terms of climate change impact.

Climate Change and Hydropower: An Uneasy Equation

According to the International Energy Agency (IEA), rising temperatures, extreme rainfall patterns, melting glaciers, and the increasing frequency of extreme weather events are posing serious challenges to hydropower projects, particularly in South and Southeast Asia.

The IEA’s Climate Impacts on South and Southeast Asian Hydropower report warns that the consequences will be disproportionate for the region. Countries such as India, Pakistan, Sri Lanka, Cambodia, Lao PDR, Myanmar, Thailand, and Vietnam will be the most affected. Hydropower capacity in these nations is projected to decline steadily until 2100, with each degree of temperature rise further worsening the impact.

This is alarming for nations like Bhutan and Nepal, where over 90% of total electricity generation depends on hydropower. A sustained decline in hydropower output could directly threaten their energy security and economic stability.

The Global Picture: A Drying Power Source

Hydropower’s vulnerability is not confined to Asia. In Zambia, the government of Ethiopia spent over $5 billion to construct the Kariba Dam across the Zambezi River, which also connects Zambia and Zimbabwe. However, a devastating drought left the reservoir’s water levels critically low, drastically reducing electricity generation and causing widespread blackouts.

The IEA’s Clean Energy Market Report (March 2024) revealed that between 2019 and 2023, droughts severely disrupted global hydropower production. In 2023, global hydropower generation recorded its sharpest decline in history, primarily due to prolonged droughts intensified by the El Niño phenomenon.

The agency estimates that had hydropower output remained consistent with 2022 levels, the world could have generated an additional 200 terawatt-hours (TWh) of electricity — enough to avoid 170 million metric tonnes of CO₂ emissions from fossil fuel-based power plants.

Environmental and Geopolitical Fallout

• Hydropower projects can also worsen flood risks, both upstream and downstream.

• Upstream, dam construction and sediment buildup increase the likelihood of flooding.

• Downstream, sudden and large water releases from full reservoirs can cause devastating floods, especially under current climate extremes.

Beyond the environmental effects, geopolitical tensions can also arise. For instance, China’s hydropower projects on the Brahmaputra (Yarlung Tsangpo) have raised concerns in India over reduced water flow, potentially impacting agriculture and livelihoods downstream.

Rethinking the “Clean Energy” Narrative

Across Southeast Asia, hydropower has long been considered the default option for cleaner energy. However, the combination of high construction costs, project complexity, and vulnerability to climate volatility makes it increasingly risky to rely on.

The energy transition must therefore diversify beyond hydropower — integrating solar, wind, biomass, and energy storage solutions — to create a resilient, low-carbon energy mix that can withstand the challenges of a rapidly changing climate.

In conclusion, while hydropower remains a key part of the renewable energy portfolio, its reliability is being undermined by the very climate forces it aims to mitigate. Without diversification and adaptation, the world’s “clean” energy dream risks running dry.

The writer of this article is Dr. Seema Javed, an environmentalist & a communications professional in the field of climate and energy