Note here, that investing in infrastructure in many cases does nothing. Building a new road to nowhere or empty buildings is a net economic loss. We should be opening up bottlenecks, looking to where things aren't done because they are too hard and too slow, and make them easy and fast. Infrastructure investment shouldn't ever be a jobs program.
I think they mean more along the lines of maintenance/repairs. The water pipes in my city are fucked. I remember watching an interview where the expert said it would theoretically take 10 years to repair it all if we concentrated ALL our resources on it (so no other city repairs for the next 10 years). Based on its own data, Montreal loses upwards of 40% of its water... that's huge. We still have some wooden pipes and somebody will have to fix it all eventually. I would not mind the city investing more money into that.