MCE Challenges Corps on Flood Study

The Missouri Coalition for the Environment has formally challenged a study conducted by the U.S. Army Corps of Engineers that concludes flood heights have decreased in recent decades on the Mississippi River .   

The conclusions of the Corps' study, which were arrived at by running a highly complex computer model, are at odds with observed, worsening trends in flooding.  For example, the 10 highest floods in recorded history on the Mississippi at Thebes , Illinois , have occurred since 1972.  At St. Louis , the ten highest floods of all time have occurred in just the last 55 years.  Flood records exist as far back as 135 years on portions of the Mississippi .

The significance of the Corps' study, first released in February 2004, is that it could be used to guide floodplain management decisions, including the extent to which commercial development will be allowed in floodplains.  Unless the flaws in the study are recognized, the Federal Emergency Management Agency (FEMA) will likely use the new flood estimates to redraw floodplain maps that dictate where development can and cannot occur.  Maps that are drawn using flawed data could end up jeopardizing billions of dollars of public and private infrastructure along hundreds of miles of the river.

Ironically, the Corps study acknowledges in many places that there appears to be a significant trend of worsening floods on the Mississippi .  For example, at one point it states that “A majority of gages analyzed throughout the study area show worsening flood trends that are significant….”  Despite this acknowledgement, the agency chose to ignore this trend, and instead relied on the questionable outputs of its computer model.

The Coalition filed its challenge using the federal Data Quality Act of 2000.  It asks the Department of Defense to "withdraw and suspend from further use” the data presented in the study.

You can view a copy of the challenge here .