from the new nei report (huge .pdf)
Amazing, the flood just missed the control room on the 2nd floor, 1st diagram I've seen that shows location of generator in basement of turbine building. Is this the first time. Why in the heck couldn't TEPCO or Generat Electric release this on day 1???? This certainly could have been made available, and the press/ / crowdsourcing could have figured out what went wrong and ways to fix the situation. Only now has TEPCO been releasing floor diagrams of the reactor buildings - they were trying to take down blueprints and diagrams rather than disclosing them in the first months.
This shows the intakes and condensors for normal cooling where completely inundated.
Generatros are in green, on the ocean side and you can see how they got flooded
Switchgear is next in yellow, also flooded.
Most amazing is that the control room in red just barely missed getting flooded by mere chance. If they were flooded, the most skilled operators would have also drowned, and could have shorted out and become totally useless even with car batteries hooked up to instruments. There is no offsite backup for the control room, and it is not flood proof.