By Jeff Opperman
As power project owners the world over become more cognizant of legitimate concerns raised by a number of international organizations, the cost many hydropower project operators have faced in providing environmental improvements for waterways is a reduction in generating capacity. However, a new initiative from The Nature Conservancy seeks to show companies how system-scale approaches can lead to balanced outcomes between river health and energy generation.
Addition by subtraction
For millennia, Atlantic salmon made an annual appearance in the Penobscot River in the state of Maine in the USA, swimming into its mouth from the Atlantic Ocean, surging up its main stem, and then scattering to spawn in the cold gravels of its rivers and streams.
Then, between 1829 and 1910, over 100 dams were built on the river, including several dams and hydropower plants on the lower river. Owners of some of the facilities began adding fish passage structures in the 1920s, but these were largely ineffective – both as individual structures and because the cumulative challenge of climbing above multiple dams was too great. As a result most of the basin lost its annual visits from these migratory fish.
Recently, another creature began to make annual appearances in the Penobscot River. Each summer, they emerged from the forest, large and yellow. And with a shuffling, halting gait, they worked their way out into the river. With long swinging necks and powerful heads, they chipped away at and eventually tore down two of the dams that had blocked the salmon.
The creatures were demolition machines that delivered a tangible outcome to years of negotiations and planning. When they were finished in 2013, the 8 MW Great Works and 8.4 MW Veazie dams and hydropower plants were gone. Meanwhile, a third plant on the Penobscot River, the 1.875 MW Howland, has been decommissioned. The dam (only 6 m tall) remains because the local community preferred to maintain the existing reservoir. The dam is now bypassed by a “nature-like” channel.
Susan Wells, national coordinator for the U.S. Fish and Wildlife’s Fish Passage Program, was recently quoted in Portland, Maine’s, Press Herald praising the Penobscot River dam removals as “the largest river restoration project in the country.”
Biologists forecasted that removal of these two dams would transform the Penobscot basin’s ability to support salmon and 11 other species of migratory fish, and early monitoring suggests this is happening. The number of river herring moving up the river has already surged from about 1,000 fish to over 900,000, and American shad numbers increased from less than a dozen to more than 1,800.
The salmon run is larger than in recent years, however, a population response to the increased habitat will not be detectable for several years because of their relatively long life cycle – with several years of growth in the ocean before returning to spawn.
Although the dam removals represent an impressive river restoration project, perhaps an even more valuable lesson can be learned by focusing on the dams that will remain on the Penobscot River. That’s because alongside the river’s rebounding fish populations, dams and their associated facilities will continue to generate hydropower.
|For more information about The Nature Conservancy and its initiatives, watch an interview with author Jeff Opperman by Hydro Group editor Michael Harris on YouTube.|
In fact, the hydropower system in the Penobscot basin will generate as much hydropower – or even slightly more – after the dam removals as it did before (about 300,000 MWh/year). The story of how diverse groups forged an agreement to rebalance energy generation and fish in the Penobscot River – and the large scale of their solution – provides a great illustration for how hydropower development and management can move toward more sustainable performance around the world.
Rebalancing energy and fish on the Penobscot River emerged as an option because all the players involved agreed to a transformation in how decisions about the river would be made.
The river had witnessed decades of battles over individual dams between hydropower companies, such as Bangor Hydro, and those advocating for the fish – including the Penobscot Indian Nation, government fisheries agencies and conservation organizations – and those battles left the parties entrenched in their positions.
In 1999, PPL Corp. purchased eight dams – all the dams on the lower river- setting the stage for another confrontation about the dams and migratory fish. But this time around, PPL, the Penobscot Indian Nation, government agencies and conservation organizations agreed to look for solutions at the scale of the entire river system.
In this case, the two lowermost dams that were most problematic for fish migration were removed and a third further upstream bypassed, while the dams that remained – which have lower impacts on fish – will see an increase in generation from their hydro facilities due to capacity upgrades and operational changes, as well as increased fish passage through fish lifts.
The scope of this win-win solution could never have emerged from a debate centered on a single dam. But by moving to the scale of the overall system, a broader set of potential solutions became possible.
To implement the solution, a coalition called the Penobscot Restoration Trust purchased the dams from PPL, funded engineering and environmental impact studies, and implemented dam removal and monitoring. Included in the trust are the Penobscot Indian Nation, American Rivers, Atlantic Salmon Federation, Maine Audubon, Natural Resources Council of Maine, Trout Unlimited and The Nature Conservancy.
The Penobscot River story illustrates a basic principle: within a river basin, there may be multiple ways to achieve a given energy target, and these alternatives can have dramatically different environmental impacts. This basic principle holds the promise that hydropower can be developed and managed more sustainably, meaning in ways that generate energy while maintaining a broader balance of other values from rivers. Examples of sustainable approaches are urgently needed because hydropower is developing rapidly in river basins around the world.
Applying the lesson worldwide
The Nature Conservancy’s Great Rivers Program is working with partners in several countries where hydropower is already rapidly expanding or is on the cusp of major expansion. In these countries, the Conservancy is working to encourage governments and financiers to adopt system-scale approaches that can contribute to meeting demands for low-carbon electricity while striving to protect rivers that are important for their environmental, cultural and/or economic values. The Conservancy also engages with hydropower developers, pursuing collaborative research and guidance on how they can lead and contribute to these solutions.
In Mexico, the Conservancy partnered with Comision Federal de Electricidad (CFE) and the Mexican Commission for the Knowledge and Use of Biodiversity on a pilot project for system-scale planning of hydropower to balance energy, environmental and social resources.
Focused on the Coatzacoalcos River basin in southeastern Mexico, the partners combined a broad range of data sources and analyzed 30 different alternatives, each representing a different combination of potential dams from CFE’s inventory.
The scientists then compared how those alternatives performed across social, cultural and environmental values. Similar to the basic lesson of the Penobscot River, the results showed the impacts to social and environmental resources varied dramatically across a range of capacity development levels.
|Veazie Dam, located on the Penobscot River in Maine was home to an 8.4 MW hydropower plant before its removal beginning in 2013.|
To illustrate, several alternatives would develop about 70% to 80% of the Coatzacoalcos Basin’s total hydro capacity. A scenario that could achieve a development level of 80% of total capacity cut off only 30% of the channel network, meaning 70% (or 1,000 km) of the basin’s river channels could remain connected and free-flowing.
However, other alternatives with slightly lower levels of energy development would have more than doubled the impact on the channel network, disconnecting 70% – leaving only 400 km connected and free-flowing.
The partners are now examining how these system-scale analyses can be used to inform national and basin scale planning for new hydropower development in Mexico, which recently announced a goal of generating 40% of its electricity from renewable sources.
CFE has recognized the value of this process, commenting via a statement that, “Through comprehensive planning, the conservation of ecosystem services can be ensured along with the welfare and preservation of the cultural heritage of the towns of the region, and the economic development of the country.”
Assessing the global impact
At less than 20,000 km2, the Coatzacoalcos is one relatively small basin. What is the international potential for system-scale approaches to hydropower development? The Conservancy recently released a white paper, The Power of Rivers, to summarize research that explores this question.
Using a global database of planned dams – compiled by Christiane Zarfl and colleagues at the Leibniz Institute of Freshwater Ecology – the Conservancy modeled hundreds of thousands of scenarios for developing hydropower in river basins, comparing business-as-usual development with “Hydropower by Design” scenarios, which strive to balance energy development with environmental and social values.
The findings showed that at a global level of development that approached projections for 2050, hydropower by design scenarios could maintain more than 100,000 km of rivers in a free-flowing condition, compared to business-as-usual approaches, for the same energy level.
Achieving these balanced outcomes in any given river basin will require collaborative solutions involving corporate practices, science, funding incentives and policy. But the global potential for balancing energy generation with free-flowing rivers is huge and should give all those involved – including governments, funders, developers and civil society – strong motivation to collaborate and forge these better outcomes.
The benefit for developers
In addition to the potential for significantly improved environmental and social outcomes, hydropower development that seeks more balanced outcomes at the system scale should also convey a range of financial and economic benefits. Individual projects developed through this approach will have lower risks of controversy, delay and conflict. Because uncertainty and delay both add to the cost of financing and developing projects, better risk management for projects will convey real financial gains for developers.
|The undertaking was hailed as “the largest river restoration project in the country” by officials from the U.S. Fish and Wildlife Service. Photo courtesy Cheryl Daigle, Penobscot River Restoration Trust|
Further, financiers will benefit from a pipeline of better-vetted and lower-risk projects. For countries, planning for more balanced outcomes at the system scale has the potential to deliver a better overall deal for development – a set of projects that work together more effectively to accomplish energy and water management objectives, along with improved social outcomes and ecosystem services from rivers.
But what about regions of the world with mature and extensive existing hydropower systems? The lesson of the Penobscot River is also relevant to these systems. For already developed basins, the frame may more appropriately be called “Hydropower by Redesign,” but the same principle applies – that some different scenarios other than the status quo may offer a better balance across values.
Planning for the future
The breakthrough on the Penobscot River was clearly facilitated by the fact that a single company had come to own all the dams on the lower river. Finding balanced, system-scale solutions on rivers with multiple project owners will no doubt pose greater challenges.
However, in a paper recently published in the University of California-Davis Law Review, professor of law Dave Owen and The Nature Conservancy’s Colin Apse proposed the concept of “trading dams,” in which system-scale approaches to mitigation could emerge through a trading system.
Trading systems have been applied to other aspects of environmental regulation, such as wetland mitigation and reducing air pollution, and the authors suggest a similar approach could help move mitigation for dam impacts, such as during relicensing processes, from the current focus on single projects toward a broader scale.
Finding opportunities for mitigation at broader scales might allow more economically efficient mitigation that can also promote other dramatic outcomes to join the example set on the Penobscot River.
“Bringing environmental trading system concepts to dams will be challenging, and so we identify a variety of policy reforms that could make those challenges more surmountable. But we see great potential for environmental and economic gain, and the Penobscot River Restoration Project exemplifies the possibilities,” Owen said.
Demand for low-carbon energy will continue to drive hydropower expansion. However, diverse stakeholders – and, increasingly, many in the sector itself – believe that hydropower must improve its environmental and social performance to ensure its place in a sustainable energy future.
Hydropower can make important contributions to a low-carbon energy mix, but to be truly sustainable it must be developed and managed in ways that recognize the diverse values of river systems. System-scale approaches to balance – or rebalance – across economic, social and environmental values are one fundamental way that hydropower can move toward this goal.
Jeff Opperman is director of The Nature Conservancy’s Great Rivers Program.