Hydropower is one those issues that can make a good green go pale with contradictory impulses. Abundant clean energy, sure, plus all that Woody Guthrie populist goodness. But also the potential for massive destruction to land and landscape, anywhere from hundreds to thousands of people displaced, and all sorts of downstream ecological and economic disruptions. About 140 countries have major dams, which generate about a fifth of the globe’s electricity and enable a sixth of its agricultural output. So while the idea of just tearing them down can have a lot of emotional appeal for some, it just ain’t that simple anymore.

Five years ago, jounalist Jacques Leslie wrote 12,000 words on the politics of water for Harper’s: “Running Dry: What Happens When the World No Longer Has Enough Freshwater?” He was intrigued enough to keep investigating once that assignment was done — and the result is a new book, Deep Water: The Epic Struggle Over Dams, Displaced People, and the Environment. Just one of his insanely alarming findings: “The world’s dams have shifted so much weight that geophysicists believe they have slightly altered the speed of the earth’s rotation, the tilt of its axis, and the shape of its gravitational field.”

(And here I’ve been freaking out about a little thing like global warming!)

An ongoing interview with Leslie is the current feature over at The WELL’s open-to-the-public inkwell conference, where readers from the wide world can send in questions for Leslie to tackle. His hopeful view is that big dams will someday be relics. Asked about the alternatives, he says:

… there’s a substantial list that includes both traditional and new technologies, including rainwater harvesting, water recycling, drip irrigation, desalination (for water supply) and solar, wind, fuel cells, and pump and turbine redesign (for energy). In the Indian state of Rajasthan, a fellow named Rajendra (my spelling may be off) won the Magsaysay Prize (a kind of Nobel Prize for the developing world) by developing a system of ponds and rainwater harvesting that recharged groundwater, revived streams, and rejuvenated villages in an arid area. I hope to write about this work some day.

This is a conversation worth checking out.

(Full disclosure: I’ve been a volunteer community host on The WELL for about a decade. This plug for inkwell may net me a warm “thanks!” in e-mail.)