Land drainage is complex and is primarily a private matter between adjoining landowners. We are the nominated land drainage authority and have some enforcement powers to make landowners carry out works to prevent serious internal flooding of domestic dwellings. Some watercourses are classed as 'controlled' and the Environment Agency will ensure that they are properly maintained and take action against those found polluting or obstructing the flow of water.
Other watercourses are classed as 'ordinary' and these are the responsibility of the adjacent landowners. This is known as riparian ownership. If your property backs onto an 'ordinary' watercourse you and the person who owns the land on the opposite bank will be responsible for the upkeep of that stream, brook or ditch for the length running along your boundary.
If you have surface water flowing onto your land you are responsible for installing suitable drainage to accommodate this flow of water. Therefore if an adjacent property installs land drains or hard surfaces their land, resulting in more water flowing onto your land, you cannot take action against that person, and must carry out your own works as required, even if that pushes the problem onto your neighbour. This is because no one owns the water, which will always find its own path.