I have been reading through the post on the structure forum, and have found it interesting. There are a couple of lakes here that has very little structure, there are crappie but most of the time they are hard to find. I was thinking about building some of these things but am not sure it is legal. Page 4 of the illinois information book around pollution says it is unlawful to put any trees, brush or other insoluble materials in the water, does that include crappie structure???