Crocodiles Are Not Geckos: The Realities Of Run-Of-River Hydropower

Too often, proponents of a specific dam apply this faulty logic and tell decision makers that a crocodile is really just a gecko.  For example, the debate on the Xayaboury Dam on the Mekong River in Laos—a massive dam that, in terms of environmental and social impacts, is much closer to Tick-Tock the Croc from Peter Pan than that cute little Geico spokesreptile—was muddied from the start by the inaccurate claim that, by being a run-of-river dam, it would have very limited impacts.

Note that in addition to the flawed logic, the common assumptions about small and run-of-river hydropower stated above have two other problems.  First, small dams can, in fact, have serious impacts (as I explore at length in this earlier blog post) – akin to living in a world with diminutive, but fatally venomous, geckos and/or otherwise normal geckos that rove around in ravenous and aggressive packs.  Second, run-of-river dams very often do affect a river’s flow pattern, but in a way that slips through a loophole in the definition of run of river.  More on that later, but now let’s explore the overarching misleading assertion that run-of-river dams have little or no impact.

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Jeff Opperman