I’d be more worried about the stove and refrigerator flying through the air.
My first thought was how many alligators might be attracted to her pond by her raccoons and other assorted pets.
There are many parasites and other nasties in open fresh water in Hawaii and elsewhere as well. I wouldn’t want to use or be in untreated fresh water in most places–too risky.
The brain eating parasite fowlerii nagirl (or something close to that, forgive me I’m on my phone and it keeps auytocorrecting really randomly) has been found as far north as michigan. Keep fresh water out of your nose.
If the tree house is a safety issue (and yes, there are things like hurricane codes to consider, as well as sanitary ones or safety like electricity) then it should be flagged for code violations and the person either fixes it or it gets torn down. One of the problems with town ordinances is that some of them have nothing to do with safety, but rather with social and political issues. For example, the post about the guy with the three car garage who wanted to put rooms above it likely was done out of fear of people renting out illegal apartments, towns for example allow “mother-daughter” kind of apartments only if the apartment is connected to the rest of the house in my area. Sometimes, too, it is about other people’s ideas of ‘what distracts from a neighborhood’, so for example by code in some towns you cannot have a wildflower garden covering your front yard (even though ecologically grass is a disaster area), they actually require you have a certain percentage grass.
You also get ridiculousness like my town, that allows builders to put up McMansions of like 4500 square feet on a quarter acre lot that literally fill almost the entire space, yet broke my chops over getting a pre build shed from agway for my back yard, even though my property is a third acre, the house footprint hasn’t changed more than a little since it was built, they were worried about it ‘being overbuilt’ (my house is maybe 2000 square feet). A lot of the time it isn’t about safety, it is about taxes, they increase your property taxes if you build out your basement, yet basement space does not (legally) count in many or most places when you measure the livable space in a house,so it doesn’t increase the value to anyone but the town…and I think that is what a lot of people see as overreach.