The hydraulic power utility is fascinating - the sheer amount of water lost via leaks from water piping in this century is huge, and so keeping a high pressure system running back then must have been tremendously difficult. Especially given a similar sized leak will have a much larger impact in a higher pressure system.
My wife did some work at a municipal water utility and they did find some wooden pipes in service in the early 2000s. The active ones are all gone, but they still find buried ones, especially around an old reservoir that was in the downtown area.
On the other hand, a leaking high-pressure pipe is extremely noticeable [1], so any damage was probably fixed asap instead of being neglected for ages.
