Nola, now that I can understand. Let me explain.
If you go back to the very early drafts (in the first post) I intended to do this map like so many others and like a few are done now even. Very simple graphics (again, like New Jersey) and a very simple classic game play. After about 3/4 weeks, I lost all interest in it and had it binned. I binned the map because of certain problems I was facing over the map. Things like impassables, breakup of territories and the rivers. When I brought the map back, it was because I had found a painting from Indonesia of a Buddhist temple. This is what got me thinking about the background and how to incorporate it. Why not paint the map straight onto the background and have it as a one level painting. This is why I resisted natty for so long as what he wanted was to bring the playing board away from the painting. As for the rivers, one thing Jakarta has is a lot of them. Main natural rivers, canals, open sewers, man mad rivers etc. If you can think of any open water, Jakarta has it. And this is what got me over the territory breakup, impassables and all of the other problems I faced. This is why some are nearly straight and others are jagged. The reason they are different from the main rivers it that there needs to be a very large difference between the ones you can and cannot cross but both still have an appearance of river/water.