If operating costs of a recirculating kayak park is only $150 an hour, I'm warming up to the idea. I like the idea of coupling it with a cafe and other amenities, sort of like a ski area base area. If you do it right, the kayak park can be a signature attraction of a cool spot.
I checked out the Penrith web site at http://www.penrithwhitewater.com.au/venue/venue.html
and it has only 18 feet of vertical drop over 8 drops. After acounting for general gradient, that's less than 2 feet per wave. It may be fine for a kayak slalom course, but I doubt it is great for surfing. They claim only one main surf wave. It does pump 500 cfs, which is healthy.
Penrith doesn't seem as fun as Golden. It's a cool concept, but it seems to be built more on the old fashion slalom concept, not play boating.
If you can build a park with a bunch of good surf spots, say 7 waves, you should be able to entertain at least 20 people at once at $20 per hour per person. You'll probably want 30-40 feet of vertical.
Perhaps the place to do this is at the current Golden WW park--if you can pump an extra 200 cfs for the length of the course, charge people $10 an hour for the months other than runoff, it may work.
A bar overlooking to the library hole, with outside seating would be a nice addition too.