[ExGeeEye]

Was it cheaper or otherwise more desirable than digging a canal?

Or would that have messed up the proper current of the Elbe and caused problems downstream?

[supercat]

Was it cheaper or otherwise more desirable than digging a canal?

Well, it would only seem to make sense if it's connecting canals on either side of the river. Even then, I wonder whether the traffic, outside of opening-day festivities, will justify the cost as compared with other alternatives (e.g. building locks to connect the canal to the river).