You are all missing the simple solution: construct another canal next to it, so the other ships can continue to pass.
( I'm joking, do not take this as a serious solution )
( I'm joking, do not take this as a serious solution )
Haha, no. Just no.
The length of the whole canal is 200km and it took 10 years to build. I don't claim that it's exactly linear, but it sounds reasonable to assume a few weeks for just a 1km segment. The soil is soft and the canal isn't deep.