There's a lot of serious work out there right now. I'll upload some photos later. They are indeed building permanent structures and putting in proper storm/sewer/water/etc. lines.
Seeing it in person makes me question the location. It seems much smaller in person, and they are putting in so many rides + at least 2 big coasters? They are going to need a TON of parking, and even if everything is scrunched together they will only have space for a small fraction of their potential customers. Perhaps they have a trick up their sleeves involving satellite parking?