Watermeadows as seen from the tower of West Overton Church.

The river has been managed as a resource since at least the 10th century when there is a reference in the East Overton charter to a series of offtakes at Uferan Tun. These could have been for drainage but may have been an early form of irrigation.
The most intensive management of the river came with the construction of the water meadows, a feature of chalk streams all over Wiltshire. West Overton is one of the few places where they have not been destroyed and although fallen into decay they still bear witness to an agricultural innovation that enriched the county for several centuries. Before the advent of artificial fertilizers sheep were folded over the arable to dung the soil. The sheep carrying capacity of the land dictated the extent of arable. The number of sheep carried was limited in turn by the ‘hungry gap’ at the end of winter when the hay was used up and the spring growth had not yet begun. Water meadows were devised to bring on ‘early bite’ and close the gap. The springs that feed chalk streams maintain a consistent temperature of about 10 degrees C so meadows could be kept frost free by allowing water to flow over them. River water also carries nutrients which enrich the soil. Deposits of gravel below assist drainage.
There were water meadows along the whole length of the river through our parish and downstream beyond it. Brickwork from the various constructions can still be seen in many places but the ridge and furrow formation typical of bedwork meadows has largely disappeared except at West Overton and, in slanting light, at Fyfield.
The flow of the river had first to be dammed by the construction of weirs and hatches so the water level could be built up.  From the resulting ponds a water carrier took water along the upper level of the meadow. The ridge and furrow beds ran parallel to each other and at right angles to the contour of the land and therefore to the water carrier. Water was released by way of sluices from the carrier to run along smaller channels cut into the crown of each bed. From here it overflowed down the sides, or panes, into the furrow and thence into a tail drain which returned it to the river.
Diagram much simplified.
A single meadow system often continued beyond a single manor. It crossed tenurial boundaries. A drowner, or manager, could be responsible to several landowners. A mill could also be involved as at West Overton where the mill leat fed the main water carrier. Precise demarcation of rights and responsibilities was needed.
The flow to the meadows was kept up throughout the winter months when there were most nutrients in the water. Short drying out periods allowed the grass to ‘air’. The meadows were ready for grazing by mid March when the sheep were folded over them by day and returned to the fields by night. As many as 500 sheep would be crowded for one day onto an acre of meadow and would then fertilize an acre of arable overnight. The flocks were moved over the meadows in sequence. At the end of April the sheep would be taken off and the meadow drowned again for the hay crop to be started. The hay would be cut in June producing four times the yield of an ordinary field, regardless of rainfall. After the hay crop the meadow could be drowned once more before summer grazing by cattle, though sometimes a second hay crop was taken off. Heavy grazing continued until October when the now trampled meadows were repaired before the winter rains.
Between the 17th Century and the 19th Century the sheep kept were Wiltshire horn, now a rare breed. Neither fleece nor carcass was the primary consideration. These sheep were bred for walking. They also thrived on the rough grazing of the downs when not on the meadow.
Primitive systems of flooding and draining for increasing the fertility of the land were practiced from the late 16th Century. Surveys of the Earl of Pembroke’s manors show many references to water mead, wette mead, and wett ground in the early 17th Century and water meadows were well documented at his Ramsbury estate. It is likely that some form of ‘floating’ (i.e. initial construction) took place on his estate at Overton. The meadows we see now are of a much later date but they appear to be laid out over an earlier system. Floating required a huge capital outlay but the improved value was also immense.
There were many reasons for the decline of water meadows: the planting of root crops for winter fodder, the introduction of improved winter grass, the repeal of the corn laws, the drift to the cities of rural labour, but for over two centuries these systems, were one of the glories of our agriculture.