The River Parrett as it enters Bridgwater.
Have you ever seen such a raised drainage channel. It must be 5 meters at least above the new bungalow gardens on the right. The flood river level is way above the surrounding land.
The actual distance between the banks is approximately 17m, the King’s drain is 30m wide in places.
Note the wall/sheet piling on the left.
Centuries ago the river would have been below the surrounding land, what has happened since?