Lake Livingston is one they try to keep it at 131' above sea level and has plenty of stumps just under the surface.
Unless you have a good map/gps unit that you can zoom into a good range that allows you stay in the river channel you can get into big trouble trying to run the river channel.
The biggest trees grow right along the edge of a river, often in places that were always too wet to log. So they are still there rotted off just under the surface.
The river takes wild twists and turns with horseshoe bends and switchback turns throughout the lake. So even with a very good map staying in the channel and not venturing too close to the old banks is difficult.
So clear lanes to run the lake are very important. If you are unfamiliar with the lake find a friend or guide who can show you the ""safe runs" from one part of the lake to another.
I bet Lake Houston has the same issues even if it is not timber you run into, but snad bars etc...