Water-meadow

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A water-meadow (also water meadow or watermeadow) is an area of grassland subject to controlled irrigation to increase agricultural productivity. Water-meadows were common in Italy, Switzerland, and England but working water-meadows have now largely disappeared. They should not be confused with flood-meadows, which are naturally covered in shallow water by seasonal flooding from a river.

"Water-meadow" is sometimes used more loosely to mean any level grassland beside a river.

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[edit] Types of water-meadow

Two main types of water-meadow were used.

[edit] Catchwork water-meadow

These were used for fields on slopes, and relatively little engineering skill was required to construct them. Water from a stream or spring was fed to the top of a sloping field, and gentle sloping terraces were formed along which the water could trickle in a zig-zag fashion down the field. The water could be used again for fields lower down the slope.

[edit] Bedwork water-meadow

Flooded bedwork water-meadow at Fordingbridge, Hampshire, England. Winter flooding has filled an old carrier channel along the crest of a ridge (running from right foreground to middle distance), and has also flooded the drainage channels (on left and into distance, where they join the river). In use, water would have seeped from the carrier channel on the right, through the grass in the foreground into the drainage channel on the left, which would have been almost empty.
Flooded bedwork water-meadow at Fordingbridge, Hampshire, England. Winter flooding has filled an old carrier channel along the crest of a ridge (running from right foreground to middle distance), and has also flooded the drainage channels (on left and into distance, where they join the river). In use, water would have seeped from the carrier channel on the right, through the grass in the foreground into the drainage channel on the left, which would have been almost empty.

Bedwork or floated water-meadows were built on almost-level fields along broad river valleys, and required careful construction to ensure correct operation.

A leat (called a carrier, top carrier or main) was used to divert water from the river and keep it at a higher level, often along the edge of the valley. This water was then used to supply many smaller carriers on the crests of ridges built across the fields. Each small carrier would overflow slowly down the sides (the panes) of its ridge, the channel eventually tapering to an end at the tip of the ridge. The seeping water would then be collected in drains (or drawns), these joining to form a bottom carrier or tail drain which returned the water to the river. The small carriers and drains made an interlocking grid (like interlocked fingers), but did not connect directly. A by-carrier took any water not needed for irrigation straight back to the river. The ridges varied in height depending on the head available – usually from around 10 cm to about 50 cm (4 to 18 inches). The pattern of carriers and drains was generally regular, but was adapted to fit the natural topography of the ground and the locations of suitable places for offtake and return of water.

A system of sluice gates or hatches, and stops (small earth or board dams) was used to control the water flow, which could be provided separately for each section of water-meadow. Sometimes aqueducts took carriers over drains, and causeways and culverts provided access for wagons when the ground was wet. The working (or floating) and maintenance of the water-meadow was done by a highly skilled craftsman called a drowner or waterman, who was often employed by several adjacent farmers.

[edit] Uses of water-meadows

The aim of water-meadow irrigation was not to flood the ground, but to keep it continuously damp – there is no standing water in a working water-meadow. Irrigation was used in early spring, to keep frosts off the ground and allow the grass to grow several weeks earlier, and in dry summer weather to keep the grass growing. It also allowed the ground to absorb any plant nutrients or silt carried by the river water – this both fertilised the grassland, and helped reduce eutrophication of the river water by nutrient pollution. The grass was used both for grazing by livestock (usually cattle or sheep), and for making hay.

[edit] Derelict water-meadows

Former water-meadows are found along many river valleys, where the sluice gates, channels and field ridges may still be visible (however the ridges should not be confused with ridge and furrow topography, which is found on drier ground and has a very different origin). The drains in a derelict water-meadow are generally clogged and wet, and most of the carrier channels are dry, with the smaller ones on the ridge-tops often invisible. If any main carrier channels still flow, they usually connect permanently to the by-carriers. The larger sluices may be concealed under the roots of trees (such as crack willows), which have grown up from seedlings established in the brickwork. The complex mixture of wet and drier ground often gives derelict water-meadows particularly high wetland biodiversity.

[edit] See also

[edit] External links

[edit] Further reading

Hadrian Cook and Tom Williamson (eds.), Water management in the English landscape: field, marsh and meadow. Edinburgh : Edinburgh University Press, 1999.

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