Are huge reservoirs something of the past? Today, a significant few the world's recommended dams are now being billed as "run of river, " which feature smaller reservoirs and, presumably, smaller impacts. Can we believe the industry buzz that run-of-river systems leave streams in a somewhat all-natural state, or tend to be such projects simply “engineering gimmicks” as previous WCD commissioner Ted Scudder has actually known as all of them?
Run-of-river dams are marketed quite like low-tar cigarettes or "lite" beer. They promise electrical energy, however with far fewer messy unwanted effects. Even the term “run-of-river” evokes pictures of free flowing, cascades of water rushing unhindered towards ocean. It seems to mean that the river is in cost, unaltered and uncontrolled. Actually, dam proponents usually utilize the terms “run-of-river” and “minimal social and environmental impacts” interchangeably whenever marketing a project. Run-of-river projects can, however, have large dam walls, significant social and environmental effects, and huge prices. Indeed, although usually run-of-river means an inferior reservoir and more normal flows, the word is not clearly defined.
Most huge dams tend to be storage space dams, meaning they store water during wet season and release it during the dry season, or hold water whenever electricity demand is low and launch it when it is high. Run-of-river projects, on the other hand, are in theory built to make certain that the quantity of water-flowing into all of them constantly equals the total amount of water flowing out of all of them (and even though many shop liquid all day, days, and even weeks at any given time).