You've never seen someone so excited by a river before, that's for sure.
As uploader tahneemh explains it, back in December the remote town of McKinlay, Queensland (population 20) was in the middle of a drought (along with 86% of Queensland) so you can almost understand his father's joyous reaction at seeing the McKinlay river flowing through the town for the first time. It's made only better by his very Aussie (read: NSFW expletive laden) outbursts.
Via YouTube