4. Are any pipes connected to rainwater downpipes?

Here are a few photographs that illustrate where internal wastewater drainage has been connected to rainwater downpipes. If your property has a separate system there is a very high chance that roof water drains straight to the nearest river or stream.  Below are a few pictures of real examples of misconnections.
  

On this property the owners or builders have gone to some effort to make a misconnections into a surface water downpipe.

Sometimes misconnections are easy to find.