Dams, although greener in some senses than coal factories in terms of their electric output, almost always have other serious environmental repercussions in the form of habitat destruction and river flow interruptions that adversely affect fish species. Hydropower from giant dams on rivers has been described as a brute force technology, and the construction of new dams can create public outcry as well as political issues in water distribution. The publication of new research, in part by The Nature Conservancy, shows how hydroelectric projects, often so destructive, can be less harmful if planned thoroughly beforehand to take the whole river basin and water system into account, rather than just a small tract of river. Jeff Opperman reports for TNC in a blog article that describes the elements of concentration, confrontation, and collaboration involved in pairing new hydropower with river conservation:
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.
Read the rest of the article, including the sections on Confrontation and Collaboration, at the Cool Green Science blog.