By Kelly Maue
It ranks as one of the worst floods and among US modern history’s top ten natural disasters. The Great Flood of ’93 occurred from April to October, overflowing the Mississippi and Missouri rivers and their tributaries. Nine states were affected—the Dakotas, Nebraska, Kansas, Minnesota, Iowa, Missouri, Wisconsin, and Illinois all experienced significant flooding.
But conditions were taking shape months earlier, beginning in the fall of 92. A wet autumn and then heavy snows in the upper Midwest saturated the ground, while cooler temperatures hampered evaporation. Much of the excess water flowed downstream. And while the St. Louis area was on the receiving end, it was starting to get hammered with its own excessive rainfall. This was only the beginning.
April marked the beginning of the Great Flood of ’93, where more than a year’s worth of rain fell in just a few months. An atypical jet stream over the Midwest resulted in unseasonably cool air moving south from Canada, colliding with moist, unstable air from the Gulf of Mexico. This weather pattern persisted and was responsible for the flooding in the Midwest. Ironically, this same jet stream was also to blame for hot and dry conditions in the Southeast. Both floods and drought devasted farmers at the same time.
The seemingly continuous pattern of rainfall in the Midwest kept dozens of rivers in flood stage for months. The Mississippi and Missouri Rivers were the main waterways, but a network of others, including the Des Peres and Meramec Rivers, plus smaller channels, were all flooding. In all, about 150 rivers and tributaries were affected.
June and July of ’93 was the wettest two-month period in the Upper Mississippi basin since data started being recorded in 1895. July 31 was the only day of that month without rain in the area. Rivers were above flood stage at approximately 600 points across the region, and over 1,000 levees ultimately failed.
The Mississippi River at St. Louis crested nearly 50 feet on August 1, 1993, almost 20 feet above the flood stage threshold. Today, a marker shows this point, halfway up the grand staircase to the Gateway Arch. During this time, it’s estimated that 8 million gallons of water churned past the Gateway Arch each second. The Mississippi remained in flood stage for more than 150 days in St. Louis, finally ending in early October. Nearby Grafton, Illinois, remained flooded for nearly 200 days.
Fifty people died, 10,000 homes were destroyed, and tens of thousands more were damaged. Millions of acres of land flooded, and shipping and transportation ground to a halt. Towns, including Valmeyer, Illinois, and Rhineland, Missouri, were relocated after the flood. The effects of the Great Flood of ’93 have continued for years.
It would be nice to think this won’t happen again for a very long time, but as temperatures rise, the chances for severe flooding do too. A warmer atmosphere can hold more water vapor, so heavy and frequent precipitation is the logical result.
Unfortunately, there is no simple solution to prevent future flooding catastrophes. Wilder weather patterns are here.
