Interesting! One of the slightly counter-intuitive solutions the city has implemented in recent years are flow restrictors in catch basins that service street storm drains. The rationale is that the sewer system can't handle the combined volume of rainwater from the street and from peoples homes (mainly runoff from gutters or sump pumps), so they opt to let the streets flood instead of people's basements.

Oddly though flooding in the city proper where there building density is high is generally not a problem. This past year when we had very heavy rains, it was the northern suburbs that had real get out your boat type flooding.