Water retention basin, a flood-control reservoir
(Slovakia)
Polder (Slovak language)
Description
Flood-Control Reservoir - a complex hydraulic facility
The construction is designed to prevent the flooding of the territory located behind the structure, to eliminate the threat of floods caused by storm rainfall and inappropriate farming, and to reduce flow fluctuation.
Purpose of the Technology: The Svacenický creek polder was built to transform Q100 flood waves.
Natural / human environment: The Svacenický creek polder is part of the flood protection of the area, which is located in the west of Slovakia in the cadastral area of the town of Myjava, in the locality of Tura Luka. The town of Myjava has been plagued by frequent floods in recent years, which have resulted in significant material damage, thereby severely hampering the quality of the local residents´ lives.
Location
Location: Myjava / Turá Lúka, Slovakia / Trenčiansky region, Slovakia
No. of Technology sites analysed:
Geo-reference of selected sites
Spread of the Technology: evenly spread over an area (approx. < 0.1 km2 (10 ha))
In a permanently protected area?:
Date of implementation: 10-50 years ago
Type of introduction
-
through land users' innovation
-
as part of a traditional system (> 50 years)
-
during experiments/ research
-
through projects/ external interventions
Flood-Control Reservoir
Classification of the Technology
Main purpose
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improve production
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reduce, prevent, restore land degradation
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conserve ecosystem
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protect a watershed/ downstream areas – in combination with other Technologies
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preserve/ improve biodiversity
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reduce risk of disasters
-
adapt to climate change/ extremes and its impacts
-
mitigate climate change and its impacts
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create beneficial economic impact
-
create beneficial social impact
Land use
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Cropland
Number of growing seasons per year: 1
-
Waterways, waterbodies, wetlands - Drainage lines, waterways, Ponds, dams
Water supply
-
rainfed
-
mixed rainfed-irrigated
-
full irrigation
Purpose related to land degradation
-
prevent land degradation
-
reduce land degradation
-
restore/ rehabilitate severely degraded land
-
adapt to land degradation
-
not applicable
Degradation addressed
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soil erosion by water - Wg: gully erosion/ gullying, Wm: mass movements/ landslides
SLM group
-
surface water management (spring, river, lakes, sea)
SLM measures
-
vegetative measures - V1: Tree and shrub cover, V2: Grasses and perennial herbaceous plants
-
structural measures - S5: Dams, pans, ponds
Technical drawing
Technical specifications
This technical drawing shows where the reservoir is localized. Blue colour presents the reservoir, red represents a complex hydraulic facility that is situated by the polder.
Location: The town of Myjava - the locality of Turá Lúka. Slovakia
Technical knowledge required for field staff / advisors: low
Technical knowledge required for land users: low
Technical knowledge required for Design and construction engineers: high (The preparatory and design documentation is needed.)
Main technical functions: control of concentrated runoff: retain / trap
Secondary technical functions: stabilisation of soil (eg by tree roots against land slides)
Aligned: -linear
Vegetative material: G : grass
Scattered / dispersed
Vegetative material: T : trees / shrubs, F : fruit trees / shrubs
Trees/ shrubs species: together 50 000 plants
Specification of dams/ pans/ ponds: Capacity 215,800m3
Catchment area: 6 km2m2
Beneficial area: 3 ham2
Slope of dam wall inside: -%;
Slope of dam wall outside: -%
Dimensions of spillways: -m
Other specifications: -
Vegetation is used for stabilisation of structures.
Establishment and maintenance: activities, inputs and costs
Calculation of inputs and costs
- Costs are calculated:
- Currency used for cost calculation: euro
- Exchange rate (to USD): 1 USD = 0.91 euro
- Average wage cost of hired labour per day: n.a
Most important factors affecting the costs
The most determinate factors that affect the costs are realization works and material used, and repurchase of land.
Establishment activities
n.a.
Maintenance activities
n.a.
Natural environment
Average annual rainfall
-
< 250 mm
-
251-500 mm
-
501-750 mm
-
751-1,000 mm
-
1,001-1,500 mm
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1,501-2,000 mm
-
2,001-3,000 mm
-
3,001-4,000 mm
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> 4,000 mm
Agro-climatic zone
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humid
-
sub-humid
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semi-arid
-
arid
Specifications on climate
Thermal climate class: temperate
Slope
-
flat (0-2%)
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gentle (3-5%)
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moderate (6-10%)
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rolling (11-15%)
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hilly (16-30%)
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steep (31-60%)
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very steep (>60%)
Landforms
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plateau/plains
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ridges
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mountain slopes
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hill slopes
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footslopes
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valley floors
Altitude
-
0-100 m a.s.l.
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101-500 m a.s.l.
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501-1,000 m a.s.l.
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1,001-1,500 m a.s.l.
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1,501-2,000 m a.s.l.
-
2,001-2,500 m a.s.l.
-
2,501-3,000 m a.s.l.
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3,001-4,000 m a.s.l.
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> 4,000 m a.s.l.
Technology is applied in
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convex situations
-
concave situations
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not relevant
Soil depth
-
very shallow (0-20 cm)
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shallow (21-50 cm)
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moderately deep (51-80 cm)
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deep (81-120 cm)
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very deep (> 120 cm)
Soil texture (topsoil)
-
coarse/ light (sandy)
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medium (loamy, silty)
-
fine/ heavy (clay)
Soil texture (> 20 cm below surface)
-
coarse/ light (sandy)
-
medium (loamy, silty)
-
fine/ heavy (clay)
Topsoil organic matter content
-
high (>3%)
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medium (1-3%)
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low (<1%)
Groundwater table
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on surface
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< 5 m
-
5-50 m
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> 50 m
Availability of surface water
-
excess
-
good
-
medium
-
poor/ none
Water quality (untreated)
-
good drinking water
-
poor drinking water (treatment required)
-
for agricultural use only (irrigation)
-
unusable
Water quality refers to:
Is salinity a problem?
Occurrence of flooding
Characteristics of land users applying the Technology
Market orientation
-
subsistence (self-supply)
-
mixed (subsistence/ commercial)
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commercial/ market
Off-farm income
-
less than 10% of all income
-
10-50% of all income
-
> 50% of all income
Relative level of wealth
-
very poor
-
poor
-
average
-
rich
-
very rich
Level of mechanization
-
manual work
-
animal traction
-
mechanized/ motorized
Sedentary or nomadic
-
Sedentary
-
Semi-nomadic
-
Nomadic
Individuals or groups
-
individual/ household
-
groups/ community
-
cooperative
-
employee (company, government)
Age
-
children
-
youth
-
middle-aged
-
elderly
Area used per household
-
< 0.5 ha
-
0.5-1 ha
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1-2 ha
-
2-5 ha
-
5-15 ha
-
15-50 ha
-
50-100 ha
-
100-500 ha
-
500-1,000 ha
-
1,000-10,000 ha
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> 10,000 ha
Scale
-
small-scale
-
medium-scale
-
large-scale
Land ownership
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state
-
company
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communal/ village
-
group
-
individual, not titled
-
individual, titled
Land use rights
-
open access (unorganized)
-
communal (organized)
-
leased
-
individual
Water use rights
-
open access (unorganized)
-
communal (organized)
-
leased
-
individual
Access to services and infrastructure
employment (e.g. off-farm)
drinking water and sanitation
Impacts
Socio-cultural impacts
Improved livelihoods and human well-being
The technology had a positive impact on the natural monument river Myjava. These are: - Reduction of catastrophic floods in the Tura Luka profile approx. 10% - Minimum flows also increased water runoff approx. 10%
Ecological impacts
habitat diversity
Destruction of the use of certain habitats
Risk towards adverse events
Reduced risk of flooding and thereby material damage.
Flood discharge in the Myjava river
10 % decrease of flood discharge
Flood discharge in the Svacenický creelk
New possibilities
New water reservoir
New habitats
Removal of riparian vegetation
Off-site impacts
reliable and stable stream flows in dry season (incl. low flows)
downstream flooding (undesired)
damage on public/ private infrastructure
Cost-benefit analysis
Benefits compared with establishment costs
Benefits compared with maintenance costs
Climate change
Gradual climate change
annual temperature increase
not well at all
very well
Climate-related extremes (disasters)
not well at all
very well
not well at all
very well
not well at all
very well
not well at all
very well
Other climate-related consequences
not well at all
very well
Adoption and adaptation
Percentage of land users in the area who have adopted the Technology
-
single cases/ experimental
-
1-10%
-
11-50%
-
> 50%
Of all those who have adopted the Technology, how many have done so without receiving material incentives?
-
0-10%
-
11-50%
-
51-90%
-
91-100%
Has the Technology been modified recently to adapt to changing conditions?
To which changing conditions?
-
climatic change/ extremes
-
changing markets
-
labour availability (e.g. due to migration)
Conclusions and lessons learnt
Strengths: land user's view
Strengths: compiler’s or other key resource person’s view
-
reduction of catastrophic floods in the Tura Luka profile by approx. 10%
-
change in the landscape´s structure, provides a new landscape element – a water area and newly constructed accompanying greenery
-
Minimum flows increased by approx. 10%
-
The construction of the polder will bring about new and improved conditions for other organisms, as it will create new habitats.
Weaknesses/ disadvantages/ risks: land user's viewhow to overcome
Weaknesses/ disadvantages/ risks: compiler’s or other key resource person’s viewhow to overcome
-
During the construction and operations arable land will not be usable.
-
Construction of the polder will create a new water area, but in terms of the technical design, the construction will not affect the water table in the greater area.
-
The effects on the air quality during the construction are normally associated with an increased risk of dust (construction, transport), but this will have a short-term impact.
-
There will be a temporary cessation of the use of certain habitats as a result of the taking of the land. It is expected that during the construction, trees will be cut down or damaged or that those habitats that are located in the bank vegetation of the Svacenicky creek and its immediate vicinity will disappear. This activity will affect approx. 0.35% of the entire length of the original riverbed. The taking of the land may result in injury or death to small mammals.
References
Reviewer
-
Fabian Ottiger
-
Alexandra Gavilano
Date of documentation: April 24, 2015
Last update: June 20, 2019
Resource persons
-
Zuzana Studvova - SLM specialist
Full description in the WOCAT database
Documentation was faciliated by
Institution
- Slovak University of Technology (Slovak University of Technology) - Slovakia
Project
- Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )
Key references
-
http://www.enviroportal.sk/sk_SK/eia/detail/polder-svacenicky-jarok-myjava http://vodotika.sk/projects/polder-svacenicky-jarok/ http://www.vahostav-sk.sk/galeria-vahostav/vodohospodarske-stavby/protipovodnove-ochrany/polder-svacenicky-jarok-myjava:
