jersey I have been where you have been with my lake. I presently have a buddie who is building a couple of Very big lakes as well!!
I actually got my 404 permit for my lake and it took ALOT of prayer!!! You can not build ANY pond or lake at all with out a 404 permit. Man it is tough!! My buddy is using his for farm purposes and that is how he got his!!

I can tell you from experiance with dealing with the core, like I said, 'been there done that', and I got the Certificate. You here all kind of stories out there. Plane and simple you need a 404 permit to build any lake or pond.

You are right there is very little to no talk on the legal aspects to all this pond and lake talk. I mentioned it one time in a post.
What you are going to have to do create a farming situation on your property to justify your lake!!!
How much land do you own with the lake??
You might be in for a long haul here my friend...