Jonathan,
You could also contact the Vancouver Public Aquarium. They have an archive of Aquarium publications and I remember seeing some old documents on the construction of thier Killer Whale habitat (both the pool itself and the above-ground portions of the display).
Unless things have changed you want to speak with Treva Ricou in the Aquarium's library. You can find Aquarium contact information on their website at http://www.vanaqua.org .
Hope this helps,
Charles