Slope schematic · an example from the Czech Sudetes

Water meadows of the Sudetes

Where will the water from this ditch go?

Author's schematic: not a map and not a plan of an actual layout. The top of the drawing is higher up the slope; water flows downhill. The narrowing of the blue water in ditch 1 shows how much is left after each successive sluice gate (settings from the “What is left for C?” section). Ditch 4 has dotted water because its amount is unknown, not zero.

water leaves the ditch: the ditch distributes
water enters the ditch: the ditch receives

Select a ditch on the plan or here

Ditch 1 · upper, along the contour

In the schematic: brings water from the stream to the sluice gates.

In the field the same shape could also intercept run-off from higher up the slope. What distinguishes the two is the side on which water enters and leaves.

Both readings and questions for the source search

The same ditch, two possible readings

Distributing means that water leaves the ditch onto the meadow. Receiving means that water enters the ditch, from the meadow or from higher up the slope. The plan shows both readings at once. A photograph of the ditch alone usually does not settle which of them is right.

Ditch 1 · upper, along the contour

Role in the schematicBrings water from the stream and passes part of it to each successive sluice gate.

Reading: distributes

On the planArrows leave the ditch downwards, onto the strips, through sluice gates or notches in the lower bank.

What would support thisGaps or notches in the embankment on the lower side, traces of sluice gates, the start of the ditch at a watercourse situated higher up.

Reading: receives

On the planArrows enter the ditch from above, from an unused part of the slope (a catch or protective ditch).

What would support thisA continuous lower bank without notches, a ditch ending in a watercourse or depression rather than on the meadow.

What the ditch alone does not settle

A course along the contour and an embankment on the lower side fit both readings. The shape alone does not show in which direction water was exchanged.

Questions for the source search

Does an old plan or map show an intake from the stream, and where it was?
At what height relative to the watercourse does the ditch begin (by levelling survey, not by eye)?
Are the traces of notches old and consistent with the rest of the layout?

Ditch 2 · downslope, along the strip

Role in the schematicA branch after a sluice gate: carries water from the channel onto the strip.

Reading: distributes

On the planArrows leave the ditch sideways, onto the turf strip.

What would support thisA start at a horizontal channel with a socket for a sluice gate or a notch in the bank; a ditch ending blindly on the meadow.

Reading: receives

On the planArrows enter the ditch from the sides; the ditch carries water downhill, to the lower ditch.

What would support thisA start in a damp spot, not at a channel; an outlet in the lower ditch or a watercourse; no traces of a sluice gate at the start.

What the ditch alone does not settle

A course down the slope does not tell whether water entered the ditch from the channel or from the sides. In both cases it flows downhill.

Questions for the source search

Does a distribution device, or a trace of one, survive at the start of the ditch?
Where does the ditch end: on the meadow, in the lower ditch or in a watercourse?
Do the other ditches in this layout have similar traces?

Ditch 3 · lower, along the contour

Role in the schematicReceives: collects the surplus from the strips and the water passing through the channel, and returns it to the stream.

Reading: distributes

On the planArrows leave the ditch downwards, onto the lower slope (off the plan).

What would support thisNotches or an overflow in the lower bank, meadow strips below the ditch, a further contour ditch lower down.

Reading: receives

On the planArrows enter the ditch from the strips above.

What would support thisAn outlet into a watercourse, no strips below, traces of run-off from the strips into the ditch.

What the ditch alone does not settle

The fact that a ditch lies below the strips does not determine the direction of water exchange. The lower ditch of one layout may be the upper ditch of another.

Questions for the source search

Where does the end of the ditch lead: to a watercourse or to further strips?
Are remains of a next layout visible below?
Do old maps describe this ditch as an outflow?

Ditch 4 · valley floor

Role in the schematicOutside the cascade: a comparison case, a ditch in a natural depression. The amount of water in it is unknown.

Reading: distributes

On the planArrows leave the ditch sideways, towards strip C.

What would support thisTraces of damming (a sill, a weir), notches in the banks, meadow strips beside the ditch.

Reading: receives

On the planArrows enter the ditch from the side, from the direction of strip C.

What would support thisNo traces of damming; a ditch that follows the course of the depression; traces of deepening of the watercourse.

What the ditch alone does not settle

A position on the valley floor does not tell whether this is drainage, a deepened watercourse or part of an irrigation layout. Such a depression naturally collects run-off.

Questions for the source search

Do old maps show a natural watercourse here?
Are there traces of damming in the valley?
How does the ditch join the lower ditch?

Without JavaScript all four ditches are shown one after another. With JavaScript, the description of the ditch selected on the plan is shown.

What is left for C?

Sluice gate A takes the stated percentage of the water flowing in the channel. Sluice gate B takes a percentage of what was left after A, and sluice gate C a percentage of what was left after B. The turf holds water only up to a limit; the excess runs straight into the lower ditch and does not feed the next strip.

The inflow is constant: 100 model units (arbitrary units, not litres or hectares). The percentages and turf limits are model assumptions, not data from sources. The same “50%” means something different for B (half of what is left after A) and for C (half of what is left after B).

Turf limit on strips A / B / C (assumed scenario) Dry: 30 / 30 / 20 units Default: 20 / 20 / 10 units Wet: 5 / 5 / 2 units

These three sets are scenarios given to the model, not a measured absorbency of the turf or a forecast of the effect on plants.

Without JavaScript the default settings are shown: sluice gates 40 / 50 / 50%, turf limits 20 / 20 / 10 units. The sliders work when JavaScript is enabled.

At the start, in the channel

100 model units, constant inflow in this example

Sluice gate A · takes 40%

Percentage of the channel water taken by sluice gate A

40%

Takes: 40 units
Held by the turf: 20 units
Run-off to the lower ditch: 20 units
Left in the channel: 60 units

The turf takes at most 20 units; the excess of 20 units runs straight into the lower ditch, not to the next strip.

Sluice gate B · takes 50% of the rest

Percentage of what was left after A that sluice gate B takes

50%

Takes: 30 units
Held by the turf: 20 units
Run-off to the lower ditch: 10 units
Left in the channel: 30 units

The turf takes at most 20 units; the excess of 10 units runs straight into the lower ditch, not to the next strip.

Sluice gate C · takes 50% of the rest

Percentage of what was left after B that sluice gate C takes

50%

Takes: 15 units
Held by the turf: 10 units
Run-off to the lower ditch: 5 units
Left in the channel: 15 units

The turf takes at most 10 units; the excess of 5 units runs straight into the lower ditch, not to the next strip.

held in the turf
excess: run-off to the lower ditch
water in the channel
turf limit
all bars on one scale: full width = 100 units

Balance: water does not vanish

100 = 50 + 50 model units

Held in the turf: 50 · to the lower ditch: 50 (through the channel 15 + run-off from the strips 35).

Strip C gets 15 of 100 units: that is what was left after sluice gates A and B.

What this page does not settle

The plan is a schematic

It does not measure hectares, irrigation time or the effect on plants. The arrows show possible readings, not an identification of a ditch in the field. Nobody should conclude on this basis that a given ditch is a former irrigation ditch.

The example is Czech

The study supplied [1] concerns systems in the Úpa and Metuje river basins on the Czech side. No Polish site has been confirmed and this page does not point to one. Transferring a Czech schematic to a Polish map requires an archival document.

A ditch is not proof

A ditch or a slope alone does not confirm historical irrigation. When the function is unknown, competing explanations remain (a protective catch drain, drainage, transit) and questions for the source search.

What is missing for a fuller version

A dated plan of one system, with confirmed publication rights.
A contemporary photograph of the slope with confirmed authorship and licence.
A source search for a Polish case. Until there is one, the page gives no Polish location.

What was removed from the earlier version, and why

The four-feature ditch key. It produced a result that looked like an identification. It was replaced by two simultaneous readings and questions for the source search.
A log of observations in the browser. Unnecessary for understanding the subject; the page saves nothing.
An inflow slider and a separate element inspector. The inflow is constant (100 units), and the roles of the elements are described by the ditch cards and the plan.

Retained: the cascade dependency (each sluice gate takes a percentage of the rest), the three turf-limit scenarios and the balance rule: the sum of water held and water returned equals the inflow.

Safety in the field

Search for relics of hydraulic engineering lawfully: along public trails and roads, respecting nature reserves and national parks. Do not enter active railway tracks, drinking-water intake areas or steep, unstable stream banks. This page is not permission to enter any place.

Sources

Rozkošný et al., VTEI 6/2022 — Irrigation: rediscovered heritage A Czech study of the documentation and protection of historical meadow irrigation systems, Úpa and Metuje river basins. Status: description carried over from an earlier version of the page; the link was not opened in this step, so it needs checking. The statement that a surviving sluice gate on its own does not say how the whole worked is this page’s wording, not a quotation.
European Traditional Irrigation in Transition, Part I (ResearchGate) A European overview of traditional irrigation as a historical land-use practice. Status: link and description from an earlier version; not checked in this step, including its earlier connection to the Sudetes context. The external site may require a login.
The plan schematic, the balance bars and the cascade model: this page’s own work. The numbers (percentages, turf limits, the inflow of 100 model units) are teaching assumptions, not measurements.