In the past few weeks, we've examined various types of infrastructure, for a couple of reasons. First, it's getting old, and we as a society have not been making the investments necessary to keep it in good condition. An example of this would be roads and bridges, which are suffering excessive wear and in some cases are nearing failure.
Second, we need to recognize that some of the technology was not well thought out to begin with. Whether limited by the state of engineering of the day, or whether unintended consequences were not envisioned, some of the infrastructure we built now requires replacement with modern technology. Examples of these would be our levees and dams.
Dams in particular are problematic. When we built most dams in the country, we could not visualize that they would bring about the extinction or near-extinction of important food resources such as salmon. They also over time have been shown to actually make flooding worse rather than better, defeating one of the main purposes for their creation in the first place. Recognition has been slowly building that many of them should be taken out in order to restore the health of the ecosystem.
Progress has been made. Per the American Rivers Network, 62 dams were removed in 2015. The largest dam removed to date is the Elwha Dam in Washington State, which was constructed without fish ladders and destroyed an entire subspecies of salmon. The good news is that salmon began returning to the river almost immediately after removal of the dam, and over time, the river should return to its previous health.
Presented for your consideration today is a fine resource to use in understanding the process of river restoration.
Recovering a Lost River: Removing Dams, Rewilding Salmon, Revitalizing Communities by Steven Hawley examines the potential for restoring the Snake River in the Western US. Not just an environmental issue, there are economic issues that also point towards dam removal as being the wise choice. Like most tough decisions, there are strong factions with vested interests on both sides of the issue, and Mr. Hawley examines the positions of each.
Emergency management and environmental protection go hand in hand in our ongoing effort to protect and serve the public. It is quite likely that sometime in your career, you may become involved in a discussion of dams, so it's a good idea to understand the issues.