Canals need regular maintenance and repair, and occasionally they need a major overhaul. The photo shows repairs currently taking place on Bloemgracht.First all the boats had to be moved somewhere else, and now a “dry” work area has been created so that the canal wall can be repaired. You can see the hose from one pump which is keeping the area relatively dry.
You can also see that the scene in Ocean’s 13 where someone swims under the canal to raise a canal house is utter nonsense
I am not a tourist 
I like this…I always wondered. Thanks for posting the picture and story!