As usual, people are not waiting for the disaster to finish happening before blaming someone for it. In this case, it is the h-ll and high water swamping the Missouri River watershed. Some have pointed at anthropogenic climate change and are saying that humanity (OK, the free market system and fossil fuels) are to blame. Others suggest that the Army Corps of Engineers is at fault.
I don’t believe the climate change argument, at least the human-caused aspect, because if you look at the terrible floods of the 1920s on the Mississippi and Missouri River watersheds, we were still in the tail end of the effects of the Little Ice Age in terms of temperatures and precipitation patterns.
Heavy snow-pack and a series of relatively warm storms that dumped rain onto snow-covered, still-frozen ground are the immediate causes for the inundations. However, the Missouri River itself and its major tributaries are highly controlled by the Army Corps of Engineers and to a lesser extent by the Bureau of Reclamation. This article (click link to read) pins a large part of the current problem on the priorities of the Army Corps’ Master Control Plan.
A little background: In the 1950s, a bureaucratic turf war developed over water control west of the Ohio River Basin. The Bureau of Reclamation and Army Corps of Engineers both wanted access to dam sites and rivers in the Midwest and West. Congress ordered them to come to an agreement. To paraphrase a whole lot of books and a rather cynical professor, each group dropped one dam, merged their wish-lists, and created the Pick-Sloan Plan. Congress blessed it into existence. The Army Corps was in charge of most of the Missouri River proper, and the Bureau got irrigation dams and projects. The job of the Army Corps was navigation and flood control, in that order, with everything else a distant third. And so it remained for decades. Then environmental protection and remediation became the first priority for the Corps on the Missouri.
As a result, the Corps changed from releasing water in summer for barge traffic (keep water levels higher than in the past so that shipping could continue into August-September) to larger, faster spring releases that simulated the old “spring rise” of the unrestrained river. This meant reducing or ending preemptive releases that had lowered reservoir levels in order to prevent flooding. So the reservoirs are full (for duplicating the spring rise) just as lots of water comes in from spring melting.
This means that if we get a year such as this one, when a sudden slug of runoff hits the river from its tributaries before the usual date for the spring floods, there’s no storage space left unless the Corps (and others) do preemptive releases. Then you have minor flooding, but not long-lasting severe flooding (one hopes. Sometimes Mother Nature doesn’t cooperate.) However, that would mean that the ACoE and other entities put flood control above other interests.
The levee system is another bugbear. Levees do prevent flooding where they are intact. They also cause the channel to deepen and flow to accelerate between them because of the Bernoulli Effect. Where the levees end, and the water can spread out again, the flooding will be worse than if there had never been levees. Rivers build their own levees with silt and sediment deposits, but the modern system constrains rivers far more and straightens them out. This also accelerates flow. And when a levee fails or is overtopped, then the damage is greater because all that water really wants to reclaim its floodplain and is going to do it. You can deliberately blow levees in order to protect downstream property, as was done in 1927 in Louisiana and Mississippi, but the cost in property and human lives was very high. Now, with better warning systems, people should be able to get out of the way. Their livestock and crops, though…
I suspect, based on what facts I know and trust, that the ACoE policies exacerbated this year’s flooding. I remember growing up in Nebraska and hearing explosions from the Missouri and Elkhorn Rivers as the ACoE dropped dynamite on ice-jams to break them up and save the bridges, as well as reduce flooding. Rivers flood. That’s what rivers do. But how reservoir systems are managed, and how the rivers are channeled and directed can make enormous differences in the degree of flooding. In an ideal hydrologic world, the Missouri and Mississippi would be allowed to return to being meandering, relatively warm streams that rose in the spring and sank in late summer and fall, spreading their waters more widely but also having a lot more room for flooding. However, that doesn’t take into account people and the needs and desires of those living in the watershed.
I’d love to see Congress and the American people revert river management back to the watershed level, as John Wesley Powell proposed in the late 1800s. Let those most affected by the rivers determine what their priorities are and how they will be managed and used. If local people favor environmental restoration over flood control and are willing to live with the potential consequences, then so be it. If they decide that flood control and irrigation come first and some critters have to be given the back seat, so be it. We managed that in the Texas Panhandle, although it took a lot of work, cash, and using up a reserve of political favors. We also live in a place where downstream flooding due to releases from the local dams is, well, ah, let’s just say there’s so much room in the main-stem reservoirs that ark building will start here last if the Most High ever changes His mind about repeating the Flood.
No one is to blame for the weather. Enviro-centric river management policies have, in my opinion, made life worse along the main Missouri than it might otherwise have been.