There are plenty of projects we should follow up with our city and state planners that could help. Like building over flow areas for rivers, keeping sewers clean, having separate sewer/drainage pipes, and adding infiltration/attenuation tanks along main road ways. CLICK HERE FOR MORE ON THAT
However, there are things we can do on our own property. Experts recommend we help the land go back to being a sponge as much as possible. While rooftop gardens may not be something your home is capable of supporting; Whenever possible it is a good idea as it helps with flooding issues and keeps your home better insulated. But probably the one of the simpler things to do is what they are doing in Europe. They have far too many very old homes and drainage systems to change at one time so instead they are encouraging sustainable drainage.
Our concrete sidewalks and driveways are not permeable. So they block and redirect rainwater in to the drainage systems. Those systems then get clogged and overflow, with considerable force, back onto our roads, sidewalks and back up our driveways into our homes.
We replaced solid concrete driveways with permeable materials such as grass and gardens, only crisscrossed with concrete. This allows rainwater to drain into the soil. Cobblestone sidewalks help too.