These structures have often been created as responses to natural landmarks such as mountains and rivers, and no other type of monumental architecture has intersected with the natural world as profoundly as dams. Dams and hydro infrastructure have played a significant role in nurturing past civilizations and societies by connecting nature, energy, and long-term collective human effort. As we move to a more sustainable future, hydropower must reprise that nation-building, nature-enhancing role.

How Hydropower Builds Nations: Stability & Development

Long before the internal combustion engine and the solar panel, there was the dam.

Throughout history, dams have been instrumental in shaping the course of human civilizations. Virtually every major ancient civilisation has utilised dams, and their implementation has consistently been a catalyst for transformative change in society. Dams have facilitated irrigation and enabled industries to access a reliable source of power, whilst also providing protection from the unpredictable and often vicious nature of rivers. In contemporary times, dams continue to represent symbols of progress and aspiration. Mao Zedong, anticipating the construction of the Three Gorges Dam in 1956, poetically referred to the project as a “great plan”, expressing wonder at the transformation it would bring to the natural world. Similarly, in 1954, Jawaharlal Nehru, the founding Prime Minister of India, referred to dams as “temples of modern India,” revered places that embodied the nation’s hopes for a brighter future.

The construction of dams has inspired profound admiration from national leaders due to the extended timescales involved. Although the installation of hydroelectric power plants may incur considerable environmental and social costs, if not properly implemented, as well as require substantial upfront investments, the long-term advantages of this technology are spread out over many generations. Dams, which may require ten or more years to construct, can remain operational for over a century—a lifespan that is unmatched by any other form of power generation. Moreover, during this extended period, dams not only generate substantial amounts of electrical energy but also create reservoirs that supply water to a nation’s expanding population and can attenuate flooding risks in some cases.

Much of turbine-based power generation is largely fossil-fuelled today, but hydropower represents a compelling sustainable alternative source of turbine-based power and associated grid stability benefits. As the world continues to shed coal and gas generation capacity, hydropower plants are taking on a growing role in anchoring grid stability. From this cushion of stability and reliability, nation-building can progress and support important energy-intensive industrial activity.

Catalysed by access to hydropower, investments in heavy industry and manufacturing can propel national economic development by leaps and bounds. Emerging economies such as Indonesia are now tapping hydropower to move up the natural resource value chain. By employing ambitious hydroelectric projects to satisfy the energy appetites of smelting and mineral processing industries, nations can step beyond simply being raw material exporters.

These transformations shape economic trajectories at the macroscopic level but also fundamentally alter ground realities at the microscopic level of communities.

How Hydropower Builds Communities: Opportunities & Skills

Large hydropower projects have in the past uprooted and displaced some local communities. For any hydropower project, the impacts at a local level need to be weighed against the broader economic and environmental advantages at a national level.

Large hydro projects in emerging markets often require consortia that call in talent and practices from overseas. This is a golden opportunity to catalyse local skill development in important areas such as civil, mechanical, and electrical engineering but also project and construction management. The complexity and long gestation period for hydro projects provide a consistent training ground to upskill and upgrade local talent.

Standing still, dam infrastructure supports a great flurry of dynamic economic and cultural activity all around them, as people improve their lives and nations advance ahead.

How Hydropower Builds Sustainability: Decarbonisation & Synergy

Economic activity today, however, must square with the demands of global energy and infrastructure decarbonisation. And hydro is more than up to the task.

Hydropower is by itself renewable, even if it is sensitive to climate-change-induced changes in hydrology and river health. At a basic level, much of hydro’s carbon footprint is embodied within the dam structure itself. Recent developments in green construction materials—and especially concrete—have been exciting and promise to drastically lower the carbon intensity of new hydro projects. The reservoirs that dams hold also emit methane and carbon dioxide from decomposing organic debris. However, most methane generation of this kind occurs in deeper parts of the reservoir, and adjusting water withdrawal depths to counter this has been found to cut down reservoir emissions by as much as 90%.

Dams are an old technology, and many dams today have been up for several decades. Another approach to improving their sustainability, therefore, is in refurbishing older dams to be more efficient in sustainable power generation: even marginally better productivity over the very long service lives of dams can easily offset the hefty initial embodied carbon.

Augmenting existing dams with new technologies can make them more than simple stone walls and give them a more active role in local natural health and sustainability. Fish ladders or cannons have become famous for helping migrating fish cross dams on their journey upstream. Reservoirs can also double up as solar plants, with floating solar farms generating additional power for dam operations or grid export. Floating photovoltaic panels can also help dampen evaporation and protect reservoir water in a warmer world.

More importantly, the synergies between other renewable sources and hydro allows hydroelectric dams and their reservoirs to become gigantic water batteries to store surplus power. This is accomplished with renewably powered pumped storage that redirects excess solar or wind power to pump water from a lower-level reservoir to a higher one, storing the energy until it is needed when the sun is not shining or the wind is not blowing. Pumped storage can also help dams regulate reservoir water levels as weather patterns shift. This powerful complementarity helps hydro and other renewable sources bolster the strength of each and counteract weaknesses.

Looking Forward: How Hydro Projects Must Evolve

Creative uses of hydropower in this way can be achieved at scale if they are better translated into cost-benefit analyses that account for the many idiosyncrasies of hydro projects. Financing models must acknowledge the high capital investment and long payback period that dams entail, but also capture the smoothed out, dispersed economic benefits from these projects: whether in terms of national and community development or in terms of the augmentation multiplier effect with floating solar farms. Shorter return timelines and a narrow, conventional evaluation of something as broad (literally and figuratively) as a hydro project may hamper and not help innovations in sustainable hydropower. This space is evolving, however, and new models of public and private financing are emerging.

Finally, what makes a hydro project sustainable differs in different contexts, cultures, and countries. The next generation of greener hydroelectric infrastructure must respect local circumstances and endeavour to find solutions that fit the priorities and needs of the communities that are impacted or stand to benefit. Dams, like any construction project, are unique. But more than that, every hydro project is tailored to the wishes and visions of the communities it serves. When striving to achieve sustainability in hydropower, it is essential to avoid the temptation to recommend one-size-fits-all solutions. Instead, sustainability strategies must be tailored to reflect the unique circumstances of each local community, including their specific cultural and emotional connections to monumental structures.