I have some family in the large public works business, so I have some persepctive here.
Large public works projects are really expensive and take a lot of know-how to get done properly. It's only been since the 70's that we've had the engineering chops to even understand how ground water works around a dam [0] let alone what to do with the older dams. The computer models of how the soil works around the transbay tube duing an earthquake is basically guessing, we just don't have good data. Heck, even with good models and good firms, you still have to just pray that the rain isn't too bad for a few years.
One of the main issues is that we just do not have a good idea what the ground/climate is doing over a 50 year timeline here in the US. Look at all the cliff-side houses in Santa Barbara, or the houses along the Mississippi, or the houses in Paradise. As such, it's very hard to insure, plan, and estimate what kinds of tolerances the public works should be built to.
To do things properly is basically a guess most of the time. As such, when that gamble fails, the clean-up is really something.
People have lived along the Mississippi for hundreds of years and the river reliably floods beyond its banks every. single. year.
The problem with dwellings along the Mississippi is the "moral hazard" by allowing the US Federal Government to insure these houses without preconditions and never denying a claim, despite the fact that one property has flooded more than 53 times in the last 50 years (claiming on flood insurance every single time).
I would argue that it's just not politically sexy to say "I am going to maintain this X" as it is to say "We are going to build this Y". They are the "blocking and tackling", but the voters are in the stands waiting for the quarterback drops back to pass long.
Large public works projects are really expensive and take a lot of know-how to get done properly. It's only been since the 70's that we've had the engineering chops to even understand how ground water works around a dam [0] let alone what to do with the older dams. The computer models of how the soil works around the transbay tube duing an earthquake is basically guessing, we just don't have good data. Heck, even with good models and good firms, you still have to just pray that the rain isn't too bad for a few years.
One of the main issues is that we just do not have a good idea what the ground/climate is doing over a 50 year timeline here in the US. Look at all the cliff-side houses in Santa Barbara, or the houses along the Mississippi, or the houses in Paradise. As such, it's very hard to insure, plan, and estimate what kinds of tolerances the public works should be built to.
To do things properly is basically a guess most of the time. As such, when that gamble fails, the clean-up is really something.
[0] https://www.youtube.com/watch?v=0EzoHXEzdwY esp. around minute 3.