A flood somewhere in Spain, can't remember which city. If it was some shithole country the buildings would have been damaged too. OP is 100% right, towns and cities flood primarily because of high density combined with lack of drainage for the water.
Normally you want urban forests, as unlike lawns or concrete or pavement, those can swallow up a large amount of water. If you don't mind noise pollution and ugliness and want to create an artificial water shortage you can also dig massive canals in concrete like LA does and drain all the water out into the ocean. These canals are empty and full of trash most of the year.