Identifying Contours on Map

Hello All,

I am trying to identify contours of lake maps for a project. Part of the difficulty is when contours in the original image intersect, and when names/numbers appear. The end goal is a set of closed, non-intersecting contours so that I can then use them to create a basic solid object from.

I have tried a number of things, but am not getting very far. Does anyone have any good ideas or methods to try?

[Ilya Gurin]

It's a pretty hard problem. Note that contours can't actually intersect, though.