This water was all diverted into a system of swales, large trenches dug with a slight slope so that water would flow through it slowly. Water levels can be controlled with pipes that can simply be raised or lowered to allow water from one swale to the next.
The swales were planted up with comfrey which ‘mines’ nutrients, pulling nitrogen, phosphorus and potassium up into the leaves. This can be harvested and used in feed or to make fertiliser.