Glycerine rivers are not caused by TD. TD just makes them more visible. You get them when your soap gets hot and then cools down slowly. To prevent them, you need to use less water in your soap or not insulate your soap as well so it can cool quicker after gel phase.
I think the reason that people see them with TD is that most TD used is the water soluble kind, and they add alot of the solution. This adds more water to that part of the soap - lowering its gel temp - so they can form easier.