If you're not aware, your fantastic generator has recently been picked up by the Wonderdraft community to create extra spiffy city maps. Here's a video detailing the current process: https://www.youtube.com/watch?v=Kp_setc0EBM He's exporting a png and working in Photoshop, but exporting an svg and working in Illustrator is actually easier.
Either way, both processes have a slowdown because they have to manually remove the background and water from each image. If the City Generator had the option to only export certain layers, it would make it a much more streamlined process. That way we could kick out a png with transparency from the City Generator, and import it directly into Wonderdraft. No extra programs or editing knowledge needed.
It's a fantastic and easy to use app, I just wanted to toss in my suggestion for improvement.