There are actually seven rivers buried underneath the city of Detroit. There have been periodic efforts to get the city to surface some of them. The French settlers of the city envisioned it as a Venice of the Midwest.
Sorry, but this is another really bad comparison to Venice.
These cities have nowhere near the history of Venice as a medieval trade metropolis, nor are they actually built on islands in a lagoon. If you must compare a city with lots of canals to a European counterpart, at least take Amsterdam.
But the name of the Californian city really is Venice (https://en.wikipedia.org/wiki/Venice,_Los_Angeles), which I guess makes it kind of awkward to compare it to Amsterdam. Not sure if the article was a "comparison" at all, though, it read more like a history piece.
Mexico City once had many canals and it was built over a lake. Today, not much of that is left, save in street names and in Xochimilco.
Thanks, hard to imagine a young L.A. it's mind blowingly big, from a little Brit's perspective.