//I'm sure it's nothing to do with what the majority of scientists have been saying for decades.//
No it isn't tomus. The bridge under the railway at Raynes Park (and one or two others I know of including the "twins" of Haggerston Road and Middleton Road which burrow under the London Overground line in North London) always floods when there is any heavy rainfall. There are a number of them in London which were all built in the same way. They are essentially large, concrete lined pits with a couple of small drains at the bottom and are hopelessly unable to deal with heavy rain. They have been doing this for as long as I can remember and probably ever since they were built - which was long before "Global Warming" and its more recent metamorphosis, "Climate Change", were ever thought of.
They often show Raynes Park on the telly when it rains. They have to get there quickly because an hour or two after the rain stops the water has drained away.
//I hope that your basement swimming pool and subterranean bespoke cinema were not affected Judge. (╹◡╹)//
Thanks, Togo. All is fine. After Brian May's disaster a week or so ago I had them both moved to the roof!