Not exactly a basement but...
Basements are rare in my part of the country but we do have a storm cellar and hope someone here can offer a clue to solve the mystery:
Previous owners said they'd never had water in the concrete block storm cellar but year before last, during a very severe drought (rainfall 29" below average) the darn thing suddenly had 3" of water in it. When rainfall is heaviest, it is totally dry! WHY?
I keep mosquito dunks in it since West Nile Virus is well known in our area. My DH is too crippled to get down there so we've never used it for anything but storage, however I don't want standing water anywhere.