To: FJB who wrote (9731 ) 1/11/2011 12:00:54 PM From: Sam Read Replies (1) | Respond to of 16955 ot -- recent 500 year floods Fifteen years after the Great Flood of 1993, floodplain development is booming grist.org It's been fifteen years since the Great Flood of 1993 put this land under 10 feet of water. Since then, thousands of acres of floodplain in the St. Louis area have been built up with strip malls, office and industrial parks, and 28,000 new homes. And all this infrastructure depends on miles and miles of levees to hold back the Mississippi and Missouri rivers the next time they try to retake the land. If you ignore the historical tendency of the Mississippi and Missouri to periodically drown it, this vast, flat landscape does present an appealing canvas for building. "When you have such an expansive floodplain, people don't have a problem with building on the fringes," says Dan Burkemper, director of the Great Rivers Habitat Alliance. "And then the fringe moves closer to the river every day." The Flood of 1993 was one of the most destructive in the recorded history of the Mississippi Basin: nearly 50 people were killed, over 70,000 evacuated, and 50,000 homes damaged on over 17 million acres (close to 27,000 square miles) across nine states. Over 16,000 square miles of working cropland was flooded, at a loss of more than $5 billion. All told, the flood caused around $16 billion in damage.... more at link above -------------------------------------------------------------------------- Here is Fox News reporting on the 500 year flood in 2008: Flooding Hits Historic 500-Year Levels in Iowa The National Weather Service called flooding in Cedar Rapids, Iowa, a "historic hydrologic event" Thursday as the swollen river poured over its banks at 500-year flood levels, forcing the evacuation of nearly 4,000 homes. The National Weather Service issued a flood warning for the Cedar River in east central Iowa Thursday, saying residents should expect "unprecedented river crests" and calling the situation serious. One of the Cedar Rapids, Iowa, levees already has broken. Read more: foxnews.com ----------------------------------------------------------------------------- Here is a more generic article on 500 year floods, written in the aftermath of the 2008 flooding:agiweb.org ----------------------------------------------------------------------------- Here is an article on flooding in GA last year that reached the "500 year" level: The United States Geological Survey (USGS) has called the flooding in Georgia “epic” in proportion. According to the USGS, the rivers and streams had flood stages so great that the odds of it happening were less than 0.2 percent in any given year. In other words, there was less than a 1 in 500 chance that parts of Cobb and Douglas counties were going to be hit with such an event. That makes the Georgia flooding a 500-year flood.... Rain began to fall on Monday, September 14, 2009 and continued to fall for over a week. During that time, several major flood records were set. Some areas got over 20 inches of rain as reported by the COCORAHS network. One record on the Chattahoochee River has not been broken since 1919. The storm system was as a result of a low pressure zone that persisted in the Southeast. Warm, moist air from the Gulf of Mexico was pulled in to create a long-lasting rain event. Ground saturation was at a high level due to previous rain events meaning the fresh rains had nowhere to go. The rain water caused runoff into streams, rivers and creeks in and around Atlanta. Interestingly, the rains were not a welcome site even after the droughts that have been associated with the region for the last 2 years.weather.about.com I hadn't heard about that one. There are more. I'm not going to bother looking though.