Downstream flooding is the big issue everywhere in the UK. The further upstream you go on any given river, the more country/park/national park land there is.

Downstream flooding is the big issue everywhere in the UK. The further upstream you go on any given river, the more country/park/national park land there is. Downstream towards valley basins you have many more towns and cities that are settlements of hundreds or in some cases more than a thousand years old, and have therefore extended from their initial (flood-aware) long term settlements, well onto their floodplains (especially from the early 1970s). In the last seventy years everything has changed so dramatically that catastrophic flooding is now routine; encouraging beavers onto farmland and helping farmers defray the costs of their habitat is almost certainly a better strategy than any kind of planned works.