When we were there 9/15-22, they were doing one of the bridges and just had it blocked off. It didn't affect the rest of SAB at all. So, just one section at a time with as little disruption as possible.
We also did not notice much disruption when we were there on September 24. It's a little harder to walk from one end to the other with the bridge blocked, but the pool itself seemed to be completely open.