https://en.wikipedia.org/wiki/New_York_City_Water_Tunnel_No._3 https://en.wikipedia.org/wiki/New_York_City_Water_Tunnel_No.... was under construction from 1970

https://en.wikipedia.org/wiki/New_York_City_Water_Tunnel_No._3 https://en.wikipedia.org/wiki/New_York_City_Water_Tunnel_No.... was under construction from 1970. I believe it's had 3 generations working on it.