Yeah, that's it!

I guess that in the previous version of EB you had the floods enabled by replacing the original descr_disasters.txt (found in EB\data\world\maps\base) with descr_disasters_floods.txt (just rename the latter into the former). The original disables floods as they may cause a bug where a permanent movement penalty is attached to the region in which the flood struck (as opposed to a temporary one). Or that the flood doesn't go away or some such thing.

You can do the same thing for 1.1; same folder, same files, same trick.