Transcript for Flood-prone Houston hit by historic rain levels
reach out and help one another. To our senior meteorologist rob Marciano. He is just outside of Houston. We just saw, rob, people have never seen anything like this but Houston is prone to flooding. No stranger to flooding. For one thing it's the fourth largest city in America so the sheer size of it contributes to why it floods so much. Houston defines urban sprawl. We are 40 miles outside of the city. This used to be farmland and just on the other side of this road you have a massive shopping center. You've got houses and roadways. That's concrete. That does not absorb water so all that has to drain into the small bayous and creeks. This was a small creek yesterday that tried to get underneath this roadway but the culvert could not handle the pressure, the volume of the water so a huge sinkhole just unraveling this pavement here. The larger rivers here are rising, many of which will go into record levels. The other issue with southeast Texas, it is flat. So all this water that wants to drain into the gulf of Mexico does it painfully slow and many will be at their banks or over into next week and close to the gulf of Mexico so when it rains here, it pours especially in a slow-moving tropical storm the likes of which we've not seen here. George. Boy, tough to watch. It certainly is. And we want to thank rob for all of his incredible reporting and
This transcript has been automatically generated and may not be 100% accurate.