Energy

Concentration, Confrontation, Collaboration: The Future of River Conservation and Sustainable Hydropower

January 28, 2016

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Waterfalls at Canaima National Park, located in south-eastern Venezuela along the border between Guyana and Brazil. A UNESCO World Heritage site; The sheer cliffs and waterfalls, including the world's highest (1,000 m), form a spectacular landscape. Photo © Ana Garcia/TNC
Waterfalls at Canaima National Park, located in south-eastern Venezuela along the border between Guyana and Brazil. A UNESCO World Heritage site; The sheer cliffs and waterfalls, including the world's highest (1,000 m), form a spectacular landscape. Photo © Ana Garcia/TNC

Concentration.

That’s what makes rivers so valuable — both for fish and for energy.

A river is the concentrated water of a whole region as rain and snow across an entire basin becomes runoff, is funneled into cataracts, creeks and canyons, and collected into the narrow ribbon of a river channel (narrow in a relative sense — even a river channel several kilometers wide is incredibly narrow compared to its basin which may be hundreds of thousands of square kilometers in area).

Fishes use these concentrated pathways to move throughout a river basin—a fluvial highway network—their travel driven by shifting patterns of resource availability and water conditions. The highway network allows migratory fishes to access habitat types and capture productivity from throughout much of a river basin, rather than being restricted to the food and conditions of one place.

Hydropower also relies on these same concentrated pathways. Water is the “fuel” for hydropower and the river basin does all the work of delivering fuel to the power plant, with topography and gravity working together to shepherd far-flung water molecules into a concentrated pathway of power.

Confrontation.

That’s what happens when the fish traveling the narrow ribbons collide with the structures designed to harness the concentrated pathways.

A recent paper in Science highlights this confrontation. In a Policy Forum article, Texas A&M fish biologist Kirk Winemiller and several dozen colleagues (including The Nature Conservancy’s Paulo Petry) describe the looming confrontation between hydropower and fish in three of the world’s great river basins: the Amazon, Congo, and Mekong.

Itaipu Dam, a binational hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay. The dam is the largest operating hydroelectric facility in terms of annual energy generation. Photo © Erika Nortemann/The Nature Conservancy
Itaipu Dam, a binational hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay. The dam is the largest operating hydroelectric facility in terms of annual energy generation. Photo © Erika Nortemann/The Nature Conservancy

Together, these basins hold one-third of world’s fish species, much of them endemic, along with some of the most important freshwater fish harvests in the world (with migratory fish generally representing the majority of harvests). Currently, these basins contain relatively few dams, but Winemiller et al. report that 450 hydropower dams are under construction or in the planning pipeline for the three basins. They review the multiple ways that dams cause losses of fish species and productivity—not just as barriers to migration but also by changing the flow patterns of a river, such as by capturing and storing the flood pulse that otherwise causes downstream rivers to swell, connecting the narrow ribbon of a river channel to the vast and productive floodplains that flank it.

Winemiller et al. suggest that project-level environmental review and mitigation cannot adequately produce balanced solutions between a basin’s ability to produce both fish and energy. Ultimately, they say, what is needed is “Integrative, strategic planning…applied at the basin scale, with the goal of finding balance between tapping hydropower potential and sustaining key natural resources.” The authors emphasize the importance of site selection and comparing alternative configurations for dam development.

Last year, The Nature Conservancy released a report that explored this recommended approach. In The Power of Rivers we produced analyses that demonstrate the potential benefits of integrative and basin-scale planning, examining alternative spatial configurations of dams within river basins and quantifying the tradeoffs between generating energy and maintaining free-flowing rivers.

For example, we compared 30 different configurations of how hydropower could be developed in Mexico’s Coatzacoalcos River basin. Several of these alternatives would develop between 70% and 80% of the basin’s total hydropower capacity (a high level because development almost never reaches 100%).   We found that several of these high development scenarios would disconnect almost 70% of the basin’s channel network, leaving only 400 kilometers in a connected and free-flowing condition. However, other scenarios that avoided the dams which had the biggest impacts on connectivity could achieve the same energy generation but would disconnect only 30% of the channel network, meaning 70% (or 1,000 km) of the basin’s river channels could remain connected and free-flowing (Figure 1).

Figure 1. Two scenarios with similar hydropower development for the Coatzacoalcos River basin in Mexico (approximately 70% of basin capacity), but considerably different levels of connectivity: Scenario 7 (far right) has 452 km affected by fragmentation compared to Scenario 21 (left) with 970 km. Analysis conducted in collaboration with Mexico’s Federal Commission for Electricity (CFE) and the National Commission for Knowledge and Use of Biodiversity (CONABIO).
Figure 1. Two scenarios with similar hydropower development for the Coatzacoalcos River basin in Mexico (approximately 70% of basin capacity), but considerably different levels of connectivity: Scenario 7 (far right) has 452 km affected by fragmentation compared to Scenario 21 (left) with 970 km. Analysis conducted in collaboration with Mexico’s Federal Commission for Electricity (CFE) and the National Commission for Knowledge and Use of Biodiversity (CONABIO).

These results, and similar results from two other river basins, illustrate the clear benefit of moving beyond project-level planning, review and mitigation and toward understanding the cumulative impacts, tradeoffs, and opportunities that are revealed by considering an entire basin or system – an approach we call “Hydropower by Design.”

The benefits of widespread application of this approach could be huge. In The Power of Rivers we drew on a global database of planned dams (compiled by Christiane Zarfl and colleagues at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries) and ran hundreds of thousands of scenarios for developing hydropower in river basins around the world, comparing business-as-usual development with “Hydropower by Design” scenarios.

Our results found that for the same level of energy development—a level that approached global projections for hydropower by 2050—Hydropower by Design scenarios could maintain 100,000 more kilometers of river in a free-flowing condition worldwide compared to business-as-usual approaches.

Finding solutions to achieve this potential for more balanced outcomes is urgent. Global hydropower capacity is projected to roughly double in the next few decades. In our report we calculated that if all the planned dams were built that there will be a global reduction in free-flowing rivers (river segments not affected by dams through fragmentation or flow alteration) of more than 300,000 kilometers, with dramatic declines in the river basins highlighted by Winemiller et al (Figure 2).

Figure 2. Changes to length of rivers (km) not affected by dams within four river basins. Changes in kilometers reflect completion of dams currently under construction and those planned from the global hydropower dams database. Note that y-axis values for the Amazon should be multiplied by 10 (e.g., the baseline length of unaffected kilometers in the Amazon is 288,000).
Figure 2. Changes to length of rivers (km) not affected by dams within four river basins. Changes in kilometers reflect completion of dams
currently under construction and those planned from the global hydropower dams database. Note that y-axis values for the Amazon should be multiplied by 10 (e.g., the baseline length of unaffected kilometers in the Amazon is 288,000).

While hydropower development will always have impacts, the results in our report, along with analyses such as those by Ziv et al. for the Mekong, show that dramatically improved outcomes are possible through application of system-scale planning.

In many ways, the technical challenge is relatively easy. Aligning decision making around potential balanced solutions is far harder. For that we’ll need to go beyond concentration and confrontation and add one more word to the fish-energy vocabulary list.

Collaboration.

There will always be a need for campaigns against dams with unacceptably high impacts. But, for conservation organizations, campaigns alone will not produce the widespread changes needed to achieve more balanced outcomes at a global scale. For that, we also need to work directly with those who plan, fund, build and operate hydropower dams and find collaborative solutions.

Fish market in the Mekong Delta, Vietnam. The Mekong River and its tributaries and floodplains support the largest freshwater fish harvest in the world. Photo © Jeff Opperman
Fish market in the Mekong Delta, Vietnam. The Mekong River and its tributaries and floodplains support the largest freshwater fish harvest in the world. Photo © Jeff Opperman

The Nature Conservancy is working in range of places, with diverse partners, to promote the kind of system-scale analyses and planning recommended by Winemiller et al. In Mexico, we are working with the Federal Commission for Electricity and other partners on basin-scale approaches to hydropower planning that balance energy generation with maintaining environmental and social resources. In Gabon we are collaborating with government agencies and providing them tools and methods to compare hydropower development scenarios to help them achieve their ambitious goals for both renewable energy expansion and conservation of ecosystems. With the International Hydropower Association and stakeholders from finance, government, industry and civil society we helped write the Hydropower Sustainable Assessment Protocol to provide a standardized tool for evaluating the relative sustainability of a hydropower project or system.

Achieving more balanced outcomes through system-scale planning won’t be easy, due to a lack of regulatory examples and structures, sector inertia and complexity, and political hurdles. These challenges are compounded in trans-boundary river basins such as the Amazon and Mekong. But based on the rate of hydropower expansion and where it’s happening—concentrated in basins where rivers support high biological diversity and are most closely linked to rural livelihoods and food sources—solutions are urgently needed. Science can point to better potential pathways, but only collaborative problem solving can deliver on that potential.

Jeff Opperman

Jeff Opperman, Ph.D., lead scientist for The Nature Conservancy’sGreat Rivers Partnership, has been working to protect rivers and lakes for more than 15 years. He has provided strategic and scientific guidance to freshwater conservation projects across theUnited States as well as in China, Africa and Latin America. Through strategy development, scientific research, and support to field projects, Jeff focuses on protecting and restoring river-floodplain ecosystems and improving the environmental sustainability of hydropower. More from Jeff

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6 comments

  1. I am a great admirer of the conservation efforts of TNC. But it is not clear to me why development projects (hydropower or others) are equated with conservation. Development and conservation seem quite opposite activities. Another question I have is how do you measure success of hydropower by design projects? Are there any successes you can point out to me?
    Thank you.

    1. From Jeff Opperman: Hi Henk, Thanks for your support and your interest in this topic. In this strategy, we don’t equate hydropower with conservation. Rather, hydropower development is a major driver of change to rivers around the world. Given the scope and pace of that change, we are trying to find solutions to promote river conservation in places where hydropower is being built. So hydropower development is the challenge we are trying to solve. Think of it as analogous to how the Conservancy works in places undergoing rapid suburban sprawl – we look to protect the most important areas with direct action, such as conservation easements, and to influence decisions about future development that can lead to landscapes with more habitat and more connections between key areas. We measure our success in the same way – in a river basin undergoing development, can our strategy lead to protection of rivers that otherwise would not be protected? Can we influence development decisions so that more rivers stay connected to promote fish migration? This is a new strategy and so our best examples are places where government planning agencies have agreed to incorporate our ideas into their planning. In the United States we have a great example on the Penobscot River in Maine, in which the Conservancy and several other NGOs and government agencies removed two hydropower dams and bypassed a third. This will dramatically improve the basin for migratory fish. Meanwhile, operational changes at the dams that remain will result in the basin producing as much electricity after dam removal as it did before. The dams have come out in the past few years and the fish are starting to rebound. Rather than hydropower by design, you could call it hydropower by redesign and it’s a great example of how a river basin can achieve more balanced outcomes between energy and environmental health.

  2. The concept of producing power generation from sea or ocean tides could be applied to rivers , and the rivers that have seasonal flows could be provided with artificial water sheds in the upstreams to hold water that can released in low flow rates of the river in order to keep a constant energy production, that way we would avoid the obstruction that dams create , and the turbines can be laid on the whole length of the river to be able to produce enough energy as from the dams .

  3. One key to solving the challenge of providing sufficient energy to meet peoples’ needs around the world (aside from wise use of it; do we really need all the electric gadgets we use? Or to light up the night sky? Or…) – is the *de-centralize* power production . Produce power in smaller amounts right where the people need it – via solar, wind, and ***micro-hydro***. Micro-hydro power production is significantly less disruptive to river ecosystems than massive hydroelectric dams.
    Not only does this save massive amounts of infrastructure needed to move electrical power over long distances, with correspondingly high costs in negative impacts on the environments, as well as in money- but the losses of power unavoidable when transferring power over long distances could also be avoided.