You think so?
They're sitting on about 39 acres \ 16 hectares.
7.5 acres \ 3 hectares of land is up behind the wavepool \ gravity wave \ kraken \ alpine slide. That's almost 20% of their land.
(In comparison, the wavepool, which is one of the largest single attractions water parks will build, takes up about 1.6 acres \ 0.6ha)
Then, when you move on to look at the rest of the park...
The alpine slide takes up about 4.5acres \ 1.8ha. Its a huge tract of land, that actually occupies very little of it. Alpine slides are awesome fun, but their capacity sucks. Maybe they can build things around it? There's plenty of opportunity to install waterslide supports, or other 'overhead' attractions, but otherwise, its a huge part of the park that could really be used in many more interesting ways.
Right inside the front entrance - theres a huge open grassed area, and a lot of picnic shelters (i assume) which is ripe for the next step up into proper park status (i remember when Jamberoo had a lot of these too).
The park's maintenance and back of house area, along with the 'non-overflow-parking' area at the front also measures about 4.5 acres. This area could be redesigned to provide access to back of house, maintenance etc, whilst utilising space closest to the park boundaries for in-park accessible area.
When you consider that between the Alpine Slide, the front unused \ maintenance area, and the as yet undeveloped land behind the wavepool amounts to almost 45% of their total land available within the block, i'd say they're nowhere near to running out of room - they just need to be smart about how the use what they have....
(and all this is without even touching the 3.5 acre carpark and overflow carpark - plenty of options to deal with that too)
Of course - with all the undeveloped land behind them - who knows what the future holds for them.... so I think your statement is a little alarmist @Boyden Hingston-Muir - and that's coming from someone who has never even looked at the park's space before yesterday.