If you built on a floodplain then there may be an argument that you are trespassing on land that rightly belongs to the river. The river’s wanderings built that land and I doubt you or anyone who previously owned that property ever negotiated with the river for it.

And I am saying this as someone in the middle of moving to New Orleans, a place humanity has been fighting with a river over for three centuries now. Someday the Mississippi will assert its claim forcefully. And New Orleanians will probably just shrug and either build up houses that sit next to canals instead of streets, or learn to grow gills. New Venice or New Atlantis.

> nearly limitless capacity for activist judges to wield the justice system according to their whims.

It'd be a nice change from activist judges who take the side of the corporations.

The US government has sued land (and won): https://en.wikipedia.org/wiki/United_States_v._50_Acres_of_L...

People have sued God (and lost): https://en.wikipedia.org/wiki/Lawsuits_against_God

People have sued search warrants (and won): https://en.wikipedia.org/wiki/Marcus_v._Search_Warrant

So you probably can! But, lacking a fixed address or any way to notify the defendant, you'd probably have the case thrown out. Also, enforcing any judgement would probably be impossible, so there's that.

The moral of the story is that courts have lots of ways to deal with situations like this.