It has long been established that the dams raid was more psychological in it's impact than much else. Even if that were true (which it isn't), it's an outcome whose importance shouldn't be underestimated.
But it is true.
The Dambusters
Extract from the above link.
How successful was the raid?
Severe flooding occurred where the Möhne Dam was breached. 1,200 people were killed including nearly 600 forced labourers from Eastern Europe who were housed in a labour camp near Neheim. Six small electricity works were damaged and rail lines passing through the Möhne Valley were disrupted. But industrial production was not affected in the long-term. When the Eder Dam broke, there were similar results. Kassel, an important arms producing town, was reached by the floodwater, but little actual damage was done. Had the Sorpe Dam been breached, then the damage would have been much greater. The potential for a major disaster was recognised by Albert Speer who commented that:
"Ruhr production would have suffered the heaviest possible blow."