Wareham's North Wall: anatomy of water meadows.

This photo was taken from the top of Wareham's North Wall.

At the bottom of the incline runs a narrow mill race (millstream, its position is traced by the black line), and just behind it the River Piddle.  Both of these are flowing eastwards, from left to right. The buildings at right are the town's North Mill; the race is partially channeled in a culvert.  A waterwheel once powered the mill here.

The race carries water provided by a hatch (or sluicegate) located upstream on the River Frome.  When the mill was working, the flow of water could be precisely regulated by raising or lowering the hatch.

The meadows beyond the river are part of a system of watermeadows, an ingenious system introduced during the middle ages.  These water meadows probably went into disuse in the early 20th century.  To see watermeadows which are still functioning, you will have to go to Salisbury.

What is a watermeadow?

Its purpose was straightforward: to provide an extra, early crop of hay to enable farmers to feed more of their animals.  This was ensured by creating a flow of water over the fields early in the year.  River water is warmer than dry fields, and its warmth enables the grass to start to grow much earlier.

For this system, the first requisite is a supply of water from a river. Hatches are installed in the riverbank, and - as with the millstream - are opened to let the water flow into a ditch (called a main).  The flow is regulated to ensure a gentle trickle of water over segments of the meadow land (called panes) and thence into a drain which ultimately returns the water to the river.  The system requires constant, expert maintenance.

You can see evidence of the system in this photo.  To the left, on the far bank of the river Piddle is a red brick footbridge with a hatch underneath. This hatch cannot be seen in this photo, but the flow of water from it northwards is clearly visible.  In the middle distance are several straight ditches, filled with water, which will have been either mains or drains.  This is by no means a complete system, as the Wareham bypass has been built over it.

What has clearly happened here is that the uncontrolled water flowing from the hatch under the red brick bridge has channelled a new stream eastwards towards Wareham's North Bridge.