system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are dams/structures in contact with water maintained?

How are structures that are constantly in contact with water repaired or maintained? I imagine there has to be some sort of preparation or specific process for this?
gpt
Concrete 100% submerged is significantly less susceptible to deterioration than concrete that goes through wet/dry cycles which would be in shallower depths. For shallow depth repair work, you can install temporary cofferdams around the work area to dewater the immediate area to complete the required work. Also divers can do many repairs, albeit slower/costlier in general.