Mark - I think it's in Tony M's wonderful sentence/observation that you may find an answer as to why those weird ponds exist:
"....Drive through the home counties of England and you will ALWAYS find at the heart of any village: the green with 22 men, in white playing Cricket with the harmonious sound of leather on willow; broken by the sharp “Quacks” from the Duck Pond, right next to the 13th century Norman/Tudor church with 12 happy Campanologists ringing in the New Year..."
The answer being, with that kind of history in hand, the Brits get to stick a pond wherever the hell they want. In other words, when the pond at Woking gets to be nearly a hundred years old, it stops being A pond and becomes THE pond -- a royal subject and subject only to itself!
(The 'answer' won't satisfy you, Mark, I realize - but I just wanted to highlight Tony's sentence)
Peter