Ive been boating on Wylie since 95. Stumps are nonexistent anywhere you would be boating and only a few sandy sholes and most are well marked. As long as you dont go too far up the Southfork past the Allan plant discharge or way north on the lake which is whats considered the Catawba river. It can get shallow the further north you go past the Allen plant intake. In the main sections of the lake, there are a couple of points that need to be taken wide though. For the most part, the lake bottom is sand a red clay. Outside of a severe drought, the water levels are fairly constant in all the lakes.
Ive heard some people complaining about stumps and underwater damage on wylie,