Yeah I might consider doing regional maps afterwards.
For flood maps, I first took http://www.heywhatsthat.com/layers.html
and set the rise to a level which I thought would be interesting.
Then, I took an elevation map (for example, this one: (warning, large image) http://www.ngdc.noaa.gov/mgg/image/color_etopo1_ice_low.jpg
I used the paintbucket tool to colour in the gradients which should be underwater as per the first map, and then I resized it and used it as a background image for the .svg file which I traced.
I mainly am concerned over the balance of the bonuses. But that can be fixed easily with testing and maybe a little bit of reshuffling.