This is just a wonderful headline.
The guy who discovered it was part of a cleaning crew trying to maintain some green space near Beaulieu, Hants (Hampshire).
“I’d just shifted a tree branch with my foot when I noticed something dark and round slowly coming up to the surface. I got the shock of my life when a Dalek head bobbed up in front of me."
I bet what he thought in the moment was Quick wheres a ---ing sofa mate!
Near as anyone can reckon, the Dalek was dumped in the pond during location filming in the 70s, during Pertwee's reign, or the 80s, during Colin Baker's stint. Odds are it's a Pertwee relic, seeing as there were three Pertwee "the Daleks" episodes (Day of, Planet of, and Death to) and one Colin Baker episode (Remembrance of the Daleks).