Storm & Flood Damage Recovery in Johnstown, NY

A confined channel draining a small watershed behaves exactly that way. There is very little room to spread between built-up blocks, so the level rises sharply instead of the water spreading out, and it falls just as fast. The practical consequence is that there is no useful interval in which to move anything, so protection for property near the channel has to be permanent rather than deployed on the day.

In balloon-framed pre-war housing that is normal. The stud cavities run uninterrupted from the sill to the roof, so water entering at an upper window or a roof junction falls the full height inside the wall and appears at the bottom with nothing wet between. Tracing it means starting at the top of the cavity rather than at the stain, and opening a small area high up saves a lot of guessing.

Usually yes, which is a more achievable target than a finished room. A stone wall has no continuous surface to seal and coatings applied inside tend to move the water elsewhere. Keeping roof and surface water away outside, then handling what still arrives with an interior drain and a sump, produces a space that stays dry enough for storage and mechanical equipment. That is a reasonable objective for this stock.