In theory I'd love a river at the bottom of the garden. Not sure about in reality though.
The advantages for us massively outweigh the downsides. Having access to a dayboat at the bottom of the garden whenever the weather is nice is an absolute privilege. The Thames doesn't flash flood, so we get plenty of warning when there will be problems, and our house is effectively on stilts so even when we've become our own little island we've never had water in the house (just in the garage).
Because of the fear of flooding, we also live in one of the cheapest houseprice areas around us.
And the cats LOVE the choice of wildlife
.