Great question. I wonder if it just depends on the location and local requirements or if some of these places predate the ordinances.

Hi Emily, I haven't been able to find out anything about how people manage to do this. I guess they get "grandfathered" in and have to build on the footprint? Cheers PS will post anything I find out.

Completely dependent on your location. Where is this?

Local ordinances dictate most requirements at waterfronts. States tend to be the main local driver, some care more than others. Rivers and oceans also get Fed requirements layered on top as well as certain DEP or EPA restrictions (like the Hudson) due to their inter-state flow, national heritage status, etc. And many structures pre-date these laws and are allowed certain leeway with respect to current laws.

Your best source would be contacting the local planning & zoning to have them advise. Or you can contact a local civil engineer and they would know.

Oooh and the Coastal Commission in CA...absolute power! Most homes and cabins on Tomales Bay are grandfathered in. Pier building is doable, but septic issues abound.

ReSquare...
Now you know location shouldn't make any difference...lol

I have seen "camps" in Maine built this way as well as homes on lakes in Tn that I think are governed by TVA. I also saw some floating homes that were totally on the lakes. A few months ago there was a Supreme Court ruling about the distinction between boats and floating homes. I am beginning to think the course of least resistance is to buy a Houseboat...lol. My particular interest was a piece of land that has a "rushing stream". I don't think it will perk so I wondered how to deal with that. I imagine the field would have to be 50 to 75 feet away. Like I said, easier to buy a Houseboat! Thanks for the info, this is looking like a hill I am too old to climb!