Originally Posted by restrac2000
Why are spillways so prone to this sort of damage? Isn't their primary purpose to be used in moments like this, ie shouldn't design incorporate these types of forces? Or are they assumed to perform well enough and repairs just assumed to be part and parcel?
Cavitation is a likely cause for these types of failures. A lot of these large dams were designed and constructed back in the 1950s or 60s or earlier, before engineers had a good understanding of cavitation and how to prevent it. Spillways can probably be retrofitted to prevent this, but it requires some infrastructure spending. Spending on such infrastructure has largely dwindled since these dams were built. For what money is spent on dam upgrades, my guess is that the Army Corps and other agencies that manage dams prioritize their projects based on risk. Overall, Army Corps is addressing some serious risks (e.g. seismic, flood, stability, etc.) at other dams and I don't know where spillways fall in the priority list.