You can laugh at the news about their predictions of the hurricane, but Houston is known to flood even with a little rain. Harris County won't spend the money to clean all the trash, trees, and brush out of the bayous and creeks. This is part of the reason for some of the flooding.
@CC1974:
Cleaning the trash and things can help, but it won't when tides are high, as they often are during tropical storms. There is nowhere for the water to go. Also, Houston has flooded since it's been a city, (and probably for thousands of years before that) so no matter what technical innovations there are some flooding will still happen. It is going to happen - we live in a wet, humid environment that gets a boat load of rain at times. Houston was a swamp before being made a city. 4951