In the original Seattle Sourcebook (back from 1st Edition), the Shadowtalk comments mentioned that the Seattle Aquarium had a secret medical clinic underneath the aquarium. These comments didn't make it into the Seattle 2072 book but I've been treating them as canon anyway.
In reality, the Seattle Aquarium is built on a pier extending into Elliott Bay. (I also happen to live across the street, so I know it well.) There is an underwater dome for visitors to walk down into to see what's going on in Elliott Bay.
I wouldn't imagine that the clinic would need sump pumps on a regular basis, but for dramatic tension, sure. Maybe the underwater dome is cracked, or leaking, or otherwise threatening to flood the clinic. Or perhaps having a secret, underwater clinic always involves a "severe risk of flooding," even under the best of circumstances.
The Aquarium should meet the "unusual and unexpected" criteria too, I would think. Let us know if that works or if you want more ideas.
