I watched a recent video about the dam and it was designed to handle a 10 year flood. Gonna spend a lot of money to accomplish next to nothing because the problems are floods greater than the 10-year. Plus, as climate changes and develop more, the 10 will become the 5; if it hasn't already, and they will still have plenty of damage.

If you really want to protect things, build it at least for the (current) 100 year flood.