http://hallofbeorn.com/LotR/Details/Flooding-THfG

The Hunt for Gollum treachery Flooding's when shadow effect references that card's "when revealed effect." Does this mean to trigger all effects that would be triggered had the card been revealed from the encounter deck during staging (including surge and doomed) or to literally trigger only the when revealed effect that is bolded: "When Revealed:"?

Thanks.

I'd say it is only the bolded: "When Revealed: (...)" effect...

The card was revealed as a shadow card so the time to trigger Surge and Doomed never happened, nor does the shadow effect says to treat the card as if it was revealed from encounter deck.

Agreed. It specifically says to do the 'when revealed' effect, so that's the only part that gets done.