First off there is a huge difference between a massive storm that hit several states and major population centers, and a middle of no where flood (relatively speaking) that happens all the time. There is only 6 million people in Missouri and far far from all of those live in the areas effected.
Secondly, these floods are hardly new... they happen every year to some degree or another, and people continue to choose to live there. Yes it is more than normal, but come on.. blame Obama for anything related to this, when the governor of the state has not even asked for federal assistance yet.. is just a tad too partisan for my taste. If the feds get involved, then I fully expect the Obama administration to do their jobs way better than Bush.. and if not then burn them at the stake including Obama.
Finally, what happened after Katrina is well documented and Bush deserved all the hatred and backlash for his response and that of his administration. Now he was not alone.. Nagen could have done much better in New Orleans, and so could have the various governors, but ultimately when they asked for federal help, it came late, was disorganized, expensive and full of Bush cronyism. I remember reading that FEMA was giving out tarp for roofs that cost them hundreds of dollars, but you could go down to the local hardware store and get the same tarp for 1/10 of the price...