Is Population increase in your area possible?

[Devonian]

Any evacuation would only be local, due to a specific threat or event.

With regards to the persistent comparisons to WWII, well that was a different time and age and the world today is a very different place and what applied then does not mean that the same will automatically happen tomorrow.

Culturally, I think it would be difficult to find any similarities between the UK of the 1940's and the UK of today.

Furthermore the nature of modern warfare has also changed and become far more sophisticated, the idea of widespread indiscriminate blanket bombing of our cities (the reason for the WWII evacuations) is crazy. It is far more likely to be one big nuke with little warning or a series of coordinated strikes against key infrastructure (Transport; Water; Power; Communications) and command/control centres.