Well Booldawg Thames Water has been trying to build reservoirs for years with constant planning issues. There's a huge one south of Oxford they're trying to build now but guess what nobody wants it next to them.
Poor pipe maintenance is the case for some authorities but not others Thames is especially bad.
As for saying we are one of the most overpopulated countries per square mile in the world - well that is simply
wrong!
We are number 48
http://en.wikipedia.org/wiki/List_of_countries _by_population_density
Funny you should mention Spain - they are very worried about water supply. They have plans to divert a river to help get water to the Med area and there's uproar about it.
It's pretty clear that climate is changing, we are starting to get lots of rain in the winter and much less in the summer. At least in the South East. This will probably continue and we need the reservoirs.
As for the trains why not do some research and find out what percentage of trains are really cancelled for leaves on the line? Rather than going on Sky News - Personally I wouldn't trust them to report on a tiddley-winks contest