The grade level of Chicago used to be many feet lower.
see City Streets: How Chicago Raised Itself Out of the Mud and Astonished the World
I forgot all about that! I'll bet some parts could be raised, IF the government could just possibly do it without jerks running the show.
I'm going to try and find pictures of this.
"Perhaps they should do like Chicago did in the mid 19th century - raise the city!"
I believe Galveston did the same thing after the 1900 storm.