One of the most interesting questions I was ever asked was this, “Will the Columbia River dams still exist in 200 years?” This was for a conference on the future of the river system, held some years ago, and sponsored mostly by Native American tribes as I recall. My job was to answer that question.
The question was put to me at that conference within the context of the challenge that dams pose to the historic importance of salmon in the Pacific Northwest, with their spawning runs diminished to the point that their existence can be threatened. But it is a very complex question – the dams enabled the electrification of the Northwest, and today provide not only renewable energy without carbon emissions (unless you factor amortize the amount of carbon emissions that went into all the concrete manufactured when they were built). In many ways the dams contributed greatly to building the communities of the greater Northwest. In addition they provide irrigation, cheap transportation for bulk commodities like wheat, and some lake-based recreational opportunities. On the other hand, recent studies of reservoirs suggest they may emit other green house gases such as methane.
But, I was forced to consider, if we had free flowing rivers today, with the electricity generation options available now, would we build all of them again? We might build some of them, but not all of them is my guess.
In 200 years, on the other hand, electricity from solar, wind, battery storage, fusion, space-based solar, etc., may provide plenty of electricity without requiring the dams. If so, in 200 years would we keep the dams operating just for the transportation and recreation they provide (plus a bit of flood control)? My best guess in that case was probably not, and that instead we would gradually remove or modify them to allow for a free or at least more free flowing river and/or management that is aimed primarily at irrigation, and enhancing salmon runs if these fish still exist. (If the salmon are gone, all bets are off.)
Sometimes events and developments confront local communities with the same question. This week the Seattle Times featured a story on the Enloe Dam in Okanogan County near the Canadian border. This dam is on a Columbia River tributary called the Similkameen River. Built 100 years ago to provide electricity, it became unprofitable and has not produced electricity since 1958 and provides no flood control It is simply now a 53 foot high barrier to what could be 340 miles of free flowing, cold water for fish. The local Public Utility District that owns the dam would like to remove it, but does not have the money to do so.
Perhaps a philanthropist will take on the project and enable it to happen. People 200 years from now may say thank you.