Willow trees ruined one of my small 1/4 acre forage ponds. I was ignorant of the potential problem they could cause and let things get out of hand. I finally poisoned them but the roots had already damaged the dam. It doesn't hold much water anymore.

Since then, I have been noticing West Texas ponds that no longer hold water. Almost without exception, they are ringed with willows and/or cottonwoods.