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
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.