That link says "Google designs zones to minimize the risk of correlated failures caused by physical infrastructure outages like power, cooling, or networking. T

That link says "Google designs zones to minimize the risk of correlated failures caused by physical infrastructure outages like power, cooling, or networking. Thus, if a zone becomes unavailable, you can transfer traffic to another zone in the same region to keep your services running." Which is clearly false if a single flood can take out an entire region.