Would love a Chiapas style Flume, they are probably more towards the future of modern water rides, and if they coupled it with some proper dark ride style sections it could be a magnificent replacement...
The issue of course, still lies with the woodland, so what if the park decided to make better use of the man-made lake that the ride currently sits on, and used that as the main area for the construction? Would it be more likely than trying to build it through the trees again?