A 4.2 Billion resort from a Chinese investor has been slated for Cairns at Yorkeys Knob and has been submitted to Government for approval:

http://aquisgreatbarrierreefresort.com/

http://www.dsdip.qld.gov.au/resources/project/aquis-resort/aquis-initial-advice-statement.pdf

Basically it would contain a Golf Course, Casino, a bunch of hotels, aquarium, lagoon, high end retail yada yada yada.

But this is Parkz of course, and one of the things slated is a "a 13 ha Water Park" (Pg 14 of the IAS)

In terms of land area, that's about the size of the Gold Coast Wet n Wild.

http://i.imgur.com/z6DNLks.jpg

The indicative location can be seen in this render.

Looks like they confused Dubai with north QLD.

I saw this on the news the other day, apparently it's a flood plain and if they actually built it there, you wouldn't be able to get in during the wet season.

looking at the artwork - the 'inner' lagoon is protected from flooding, and the outer ring looks like it has a tidal wall surrounding it. If it flooded regularly, they'd work out to get their customers across the waters by boat or helicopter... or even a chairlift style...

As for the waterpark - I think it needs to be either closer.. or they'll need a good transport system nearby.