That part of the zoo is very exposed to flooding, and is very flat. I don't know much of the details about the 2002 flood, except that I remmeber seeing it on the news in NZ (the hippo in the city canal) and the signs showing its effects in the zoo itself. Many of the species in that area now (especially the big cats) wouldn't be easily moved if a flood threatened the zoo again. Presumably they have built stop banks and other defences in case a similar event occurs again.
