Ok so the modern thinking is not to use a bouncing bomb from 60ft agl and the cushioning effect of the water, but to rely upon the high kinetic energy of a weapon guided onto the dry side of the dam, and hope it makes more damage than a nicely drilled 2ft diameter round hole.
Just looking at some American ordnance, they have a GBU-28, then a bigger MOAB, then the 15 ton MOP, which could create the desired effect. All of which can be dropped from several tens of thousands of feet, so no low level flying required...
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