I have a 2012 Octavia 2, bought in 2013, with 10,000 recorded mileage which is 111194.

The vehicle has been reliable but recently has shown signs of having water in the boot. Right now it is bone dry. I use a car port here at home.

Can Briskoda tell me how water might be getting in ? I want to fix this problem before the rains return !

A known candidate is the connection between feed pipes for the screenwasher, IIRC pax side boot to rear of the wheel arch. There are numerous discussions regarding same on here - worth a search.

BTW does the leak water look/feel like what you're putting into your screenwash reservoir under the bonnet?

Another leak candidate would be the tailgate seal, but that would only appear after getting rained on (or carwashed).