The parents of one of my old schoolmates lived on a family farm bordered on two sides by the same river. The river itself was the dividing line between two counties.
Their house was high on a hill so despite the occasional flood, the water never reached their house, but they were often trapped and couldn't leave until the water went back down.
After one major flood, the river totally changed course, and the main channel now ran on the south side of their house, instead of the north side like it had for as long as they could remember.
The change in the river left the old river like a horseshoe lake, but they were not trapped, as a rise left them with a means of access, but they now had to drive like two miles around to get to the road.
Although they still live in the same county, they have to rely on the adjoining county for all their police, fire and ambulance services now, because they are on the other side of the river, hi hi...
I'm using the details of their incident in one of my stories, but not with a house, I chose to make it a popular park instead. It just worked out better that way in the story.
Where my brother used to have a fishing cabin, every time there was a flood, it was another ten to twenty feet from his cabin to the rivers edge. Once when the water was so low you could step across the river, he brought in a backhoe and removed all the gravel and mud only in front of his property, and built a forty foot long pier from his cabin out to where the new edge of the river was. When the river got back up to its normal water level, the water was eight to ten feet deep from the front of his cabin out to the end of his fixed height pier, then alongside that at the end, he had a floating boat dock. Enough fish took up residence in the cleaned out area, you could catch anything fishing off the pier.
A storm knocked a tree across his cabin, and they would not let him rebuild, since he was in a flood plain.
The fellow he sold the property to used the pier to place a large tent on when he came to fish.