Its quite an interesting story about Venice Beach.  There were many more canals that were filled in during  the late 1920's mostly because of the automobile (also difficult to maintain).  If you recall when visiting Venice that sometimes there were random wide roads for no particular reason, those were likely canals that were filled in.   Check this out [Original Venice Canals](https://www.dailymail.co.uk/news/article-3114848/Venice-America-s-history-shows-canals-hidden-pavement.html)