Forget the dams proper, target their power plants and substation. WW2 and the attacks on the Roer dams showed just how hard it is to take one down. taking out the power plants is a far easier task with equally devastating effects.
I would target those elements of Iranian society that oppress their people (e.g. those military and police organizations that put down rebellions). Also take out their nuclear facilities and missile research.
Well, I might think that way too, if limited to WW2 weaponry and techniques.
GPS = one 5,000 lb. bomb placed correctly (that’s the key), dam failure initiated, the water will do the rest.
Really big dams (China’s 3 Gorges) are tougher, but Iran has a lot of medium size, high dams - much easier to initiate failure, and then the electricity is gone too.
Plus, living in an area often subject to major floods, I have to disagree on “equally devastating”. That esp. since Iran has fresh water shortage problems to begin with. Electric out + flooding + no fresh water will get attention in a hurry.