We camped on the small isthmus and it has huge power lines right down the middle. We ended up right under them and had no issue (no buzzing)

There are BIG power lines that cross the lake but there are several spots around the lake that are not right under them (though some are). We camped about 300 yards from them.

Not big power lines. I recall there being big lines in the distance, and then a smaller set of lines that came close to one side of the lake. Where I camped, which was on the south-eastern portion of the lake, had no lines.