Kaligandaki Hydroelectric Power Station in Nepal. Photo: Wikimedia Commons, Eken7
Kaligandaki Hydroelectric Power Station in Nepal. Photo: Wikimedia Commons / Eken7

Leaders from around the world recently spent two weeks in Glasgow hammering out an agreement on the next 10 years of global climate action. The representatives who gathered for the 26th UN Climate Change Conference of the Parties (COP26) focused primarily on the much-needed transition from fossil fuels to clean energy alternatives.

But as leaders return to their home countries and begin the hard work of delivering on their commitments, they need to understand that some alternative energy sources have larger ecological footprints than others.  

Hydropower in particular brings with it certain hidden costs that nations should be aware of, lest they end up irreparably harming rivers in the name of clean energy.

Generally viewed as a  low-carbon energy source, hydropower makes an enticing alternative to fossil fuels. And yet poorly conceived hydropower dams can lead to flooded communities, declining fisheries, degraded or destroyed wildlife habitats, and other major disruptions for people and nature. 

To be clear, hydropower has played a critical role in stabilizing electrical grids and enabling the expansion of the world’s renewable energy supply, and will continue to do so for the foreseeable future. But if we aren’t smart about implementation, we risk squandering precious natural resources that have undergirded human health and well-being for millennia. 

Infrastructure development and other man-made changes have already fragmented or disrupted two-thirds of the world’s longest rivers. Dams, including hydropower dams, are the leading cause of this loss in river connectivity.

They can block upstream-downstream fish migration and cause other disruptions that place pressure on ecosystems already pushed to the breaking point by destructive fishing, excessive or inefficient irrigation, toxic pollution and climate change.  

It’s hard to overstate just how dire the situation has become for Earth’s rivers, streams and other freshwater ecosystems. Since 1970, freshwater wildlife populations monitored by WWF’s Living Planet Index have experienced a staggering 84% decline on average. This decline has serious implications for the 200 million people who depend on freshwater fisheries for food and the 60 million who depend on them for their livelihoods. 

Dams also can negatively impact downstream deltas, which are home to 500 million people and produce 4% of the world’s food, making them among the most productive agricultural regions on the planet. Free-flowing rivers carry sediment and nutrients that help maintain these fertile regions; without them, deltas are more vulnerable to rising seas.   

The problem is in the planning

Environmental reviews of hydropower projects are generally conducted at the level of an individual dam and rarely factor in the system-level or cumulative impacts that such projects can have on river basins and even entire countries. Such reviews also tend to only occur after a project has significantly progressed, thereby hamstringing efforts to avoid, minimize or mitigate negative impacts on rivers.  

Given the risks involved, how can nations chart their course to a clean energy future without sacrificing the rivers and other freshwater ecosystems that sustain them? For the answer to that question, we must look to the small South Asia nation of Nepal.

Nepal’s remaining free-flowing rivers have cultural significance for its people and provide them with a wide array of ecosystem goods and services, including water supply, biodiversity, tourism, recreation and more. But the immense value of these “natural assets” is rarely factored into cost-benefit analyses, and top priority continues to go to water use for irrigation and hydropower production, which generates nearly all of Nepal’s electricity.  

Last year, the government submitted Nepal’s second Nationally Determined Contribution (NDC) document to the United Nations. The document, which outlines Nepal’s climate ambitions over the next decade, includes a commitment to expand clean energy generation from less than 1,400 megawatts to 15,000MW, nearly all of which is currently planned to come from hydropower.

Chance for balance in Nepal

Nepal has committed to supplying 15% of the total energy demand from clean energy sources, though that term remains vaguely defined.

Technical studies funded by the United States Agency for International Development (USAID) and conducted by World Wildlife Fund (WWF) and partners recently examined how Nepal could balance the protection of its rivers with its development of low-carbon, low-impact and low-cost power systems.

The studies found that it’s possible for Nepal to keep its rivers free-flowing with a minimal increase in financial costs for energy-system development – but only if the government embraces early and comprehensive planning that moves away from single projects and toward whole systems.  

System-level planning involves looking at different pathways for meeting a country’s future electricity demand and comparing the costs and benefits of each pathway – not just in terms of energy costs, but also in terms of impacts on fisheries, river-related recreation, biodiversity and other social-cultural values.

The goal is not to identify a perfect solution, but rather to help decision-makers better understand the tradeoffs involved and plan accordingly.  

For example, WWF’s studies showed that keeping the Karnali River, the country’s largest remaining free-flowing river, and its major tributaries free of hydropower development would result in only a 1% increase to the nation’s total electricity-system costs.

By comparison, a pathway that avoids dams in Nepal’s protected areas would increase costs by 2%, while a pathway that avoids dams on all of the nation’s free-flowing rivers would increase costs by 9%.  

Collectively, these studies provide Nepal’s government with the insights needed to preserve many of its most important rivers – along with their diverse cultural, economic and environmental values – while also building a low-carbon and low-cost power system that can meet the country’s growing needs for electricity.  

We hope Nepal seizes this opportunity to choose a sustainable path forward for its people. In doing so, Nepal could show the world that it’s possible to balance scientific insights with the objectives of diverse stakeholders and forge balanced solutions for energy and development.

If other nations follow their example, the world will be one giant step closer to a clean, stable future in which people and nature thrive.  

Nik Sekhran

Nik Sekhran is chief conservation officer, WWF-US.

Ghana Shyam Gurung

Ghana Shyam Gurung is country representative, WWF Nepal.