This article first appeared in the St. Louis Beacon, June 17, 2011 - It's only June but one thing is certain: 2011 is another extraordinary flood year. The record high water levels just experienced on the Mississippi from Cairo to Baton Rouge will soon be joined by new record levels on the Missouri River at numerous sites above Kansas City. The vagaries of rainfall delivery will dictate how bad things will become and how far downstream serious problems will propagate, but indications are that many dozens of levees will fail, either by overtopping, under-seepage or simply because they will be water saturated for long periods of time.
How is it that this extraordinary flood year came so soon after the extraordinary flood year of 2008, which came so soon after the extraordinary flood years of 2001, 1995 and 1993? The explanation is that damaging episodes of high water are no longer statistically extraordinary, but rather represent the new norm. Describing these events as "50-year," "100-year" or "500-year" floods grossly mischaracterizes what's happening.
Understated flood risk is not an academic matter. Faulty risk calculations are used by FEMA to set flood insurance rates that are too low and to define flood zones that are too narrow.
Understated risk promotes development projects that place property and lives in hazardous areas. Ironically these same developments encroach on rivers and floodplains in a way that amplifies flood frequency and increases floodwater levels. At the same time, valuable farmland is destroyed, habitat is eliminated and surface water and ground water resources are degraded.
In cases where floodplain development projects are encouraged by TIFs and other inappropriate financial inducements, tax revenues can actually go down, even as municipal responsibilities to provide services such as police and fire protection go up.
Counterproductive enough? Not for some. Now combine the high and progressively increasing likelihood of flooding with the placement of nuclear materials in floodplains. Let's examine two examples.
Incredibly, large volumes of the oldest radioactive waste materials of the Atomic Age were dumped at West Lake landfill in Bridgeton in 1973. From every conceivable viewpoint, the situation is deplorable. Radwaste does not belong in the most populous county in Missouri, near the Missouri River, upstream of several water intakes and within 1.5 miles of Interstates 70 and 270.
This site has high risk factors for flooding and is underlain by soils that have high potential to undergo liquefaction during seismic shaking. USGS maps indicate that the potential for strong shaking is significant in this area, so the possibility for slumping of the landfill or the protective levee is significant, particularly during flood years when shallow sediments become saturated. Moreover, the landfill does not have a clay liner or any other protective barrier, nor does it have the leachate collection and drainage systems that are standard in modern landfills.
The landfill is not capped, so wind erosion and rainwater penetration can disseminate radwaste. Historical slumping of the landfill has already spread radwaste over adjacent fields. The waste has not been adequately characterized, but enough is known to establish that its level of radioactivity will increase approximately tenfold over time. This can occur because the systematic decay of the radionuclides produces several additional short-lived "daughter" radioisotopes that will cause the radioactivity of this waste to grow for thousands of years. Few things are as absurd as burying such waste in a substandard landfill in a floodplain in a populous area.
As another example, two nuclear power plants in Nebraska have been constructed in the Missouri River floodplain where new records for flood levels are expected to be set this June. The Fort Calhoun Nuclear Plant has been recently sandbagged, only a year after the plant was cited for having inadequate flood protection. Floodwaters are already adjacent to several of the buildings, and water levels are projected to increase by at least five feet. Fortunately, the reactor was recently shut down for refueling, but about 300 tons of spent fuel rods have accumulated onsite over the years. Make no mistake; some of the most serious, recent problems and explosions at the Fukushima Daiichi nuclear plant involved spent fuel, not just the active reactors.
Of course, the NRC and power industry promoters routinely assure us that the risk of nuclear accidents is incredibly low, something akin to the probability of being attacked by a shark while riding a ski lift. The historical record provides a more realistic and vastly higher assessment of nuclear risk. More than 2 percent of the world's 440 nuclear power reactors have been irreparably harmed by nuclear accidents during their operating lifetimes - prominent cases are Chernobyl, Three Mile Island and Fukushima.
The bottom line is that understated risk is rampant and the consequences can be economically and environmentally disastrous. Understated risk fosters inappropriate land use in high-risk geologic areas, causing harm that can spread far beyond the boundaries of the offending properties. In contrast, realistic risk calculations and improved economic assessment of construction projects will promote wise land use and resource conservation, while reducing the economic burden caused by flooding or other disasters. Thoughtful stewardship will increase opportunities for research, innovation, enterprise and job creation, and ensure a brighter and more equitable future for all.
Bob Criss is a professor in the department of Earth and Planetary Sciences at Washington University. He is the coauthor of the 2003 book, "At the Confluence: Rivers, Floods, and Water Quality in the St. Louis Region." .