This has importance because FEMA requires that any building in the flood plain have a hole in two different walls, to the tune of 1 square inch of opening size for every square foot of interior area for the building. Which leads to the other fallacy - that there is substantial current on Lake Travis that would pose a danger to property, the way the Miss. River would certainly turn a floating house into a battering ram downstream. It is the interpretation of the inspector that the holes must be in two opposing walls, although the precise text does not say this. Flood dynamics on Lake Travis are different than a moving river. The lake gets you wet, but there is no current to speak of.
Hydraulic forces are MUCH different than a typical river flooding.
This means that simple doors or garage doors that would collapse under water pressure are not acceptable. The electrical sockets in the garages and other rooms would have to be made totally waterproof. NOT weather resistant, but totally waterproof. If they cannot be made so, they must be removed. All wall switches and lights must likewise be removed if they cannot be made totally waterproof.