Melioračný kanál Tvrdonice – fishing districts

Today on the Melioračný kanál Tvrdonice watercourse

Is it worth going today? Fishing conditions score, the best window of the day and fishing districts from the best conditionsConditions score46 / 100Best window15:00

Average of the watercourse's fishing districts

46from 100

Average activity · average of one fishing district

The number in the header is an estimate for the middle of the watercourse based on weather and measurements. The average of the fishing districts also counts satellite data, shading and geology of each district.

Best window today

15:00–17:00

Melioračný kanál Tvrdonice, window score 48.

The score is an estimate of conditions based on weather, water and surroundings, not a bite forecast. Recalculated at 07:22.

Map and fishing districts of the Melioračný kanál Tvrdonice watercourse

The course of the watercourse and its fishing districts. You can switch the line color to today's conditions, quality or any other parameter.Fishing districts1Length12,6 km

Detailed filtersregion, district, riverbed, depth, shading, satellites, water chemistry and pollution, fish, geology

Region

River basin

District and local SRZ organization

1445fishing districts

Pick a category to narrow the selection. Next to each option you can see how many fishing districts remain.

Map color

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Move the map with two fingers. In full-screen mode one finger is enough.

Sort fishing districts

Fish and catches on the Melioračný kanál Tvrdonice watercourse

Which fish live here and what has been caught? Game species recorded in the fishing districts and approved catches by anglersGame species7

Game species recorded in the fishing district

Anglers' catches

Nobody has added a catch from these fishing districts yet.

Add a catch

Organizations and districts on the Melioračný kanál Tvrdonice watercourse

Who manages the fishing districts and where they areOrganisations1Districts1

Organizations on the watercoursewho manages the fishing districts and what the conditions are there today

Holíč1 fishing district · 13 km46Melioračný kanál Tvrdonice46

Skalica district, Trnava Region

Water pollution on the Melioračný kanál Tvrdonice watercourse

Water quality according to SHMÚ, wastewater treatment plants near the fishing districts and groundwater nearbyDistricts failing a standard1 / 1

Groundwater: measured valuestypical value from stations within 10 km, 2025

1 of 1 fishing district with measurements has groundwater nearby with a value above the limit for at least one indicator.

harmful substances above the standard at at least one station (metals, pesticides, PFAS, solvents)1
ammonium or nitrites above the standard at at least one station1

Polluted water in Slovakia

Source: SHMÚ (yearbooks on surface and groundwater quality), the register of wastewater treatment plants from VÚVH and the EEA. A SHMÚ site is assigned to a fishing district by the same watercourse name and by distance; the yearbook lists the sites that failed the standard, so a missing site is not proof of clean water.

Terrain and satellite images of the Melioračný kanál Tvrdonice watercourse

Elevation profile, 3D terrain of the surroundings and historical satellite imagesHighest point163 m n. m.Lowest point155 m n. m.

Elevation profile of the watercourse

How the watercourse falls downstream: fall, gradient and water speed.

Slow watercourse A lowland river with a calm current, shallows along the banks and deeper pools in the bends.

Elevation profile of the watercourse: from 163 to 155 m a.s.l. over 12.5 km.

Fishing districts in order from the highest (left) to the lowest. There may be a section without a fishing district between districts; it is not displayed.

Highest point: 163 m a.s.l.
Lowest point: 155 m a.s.l.
Fall of the fishing districts: 8.2 m
Average slope: 0.7 ‰
Sinuosity: 1.09

Source: Open Topo Data (eudem25m), 4 Nov 2026. Gradient and fall are approximate and include only the sections of fishing districts.

Terrain in 3D

Loading the 3D terrain model…

Historical images

Changes in the surroundings and nature from 2017 to 2023: how the banks, vegetation and landscape around the water change. The images switch automatically; you can also browse them by hand.

Aerial image of watercourse Melioračný kanál Tvrdonice from 2017 — **2017**imaged 24 Aug 2017

Aerial image of watercourse Melioračný kanál Tvrdonice from 2020 — **2020**imaged 22 Aug 2020

Aerial image of watercourse Melioračný kanál Tvrdonice from 2023 — **2023**imaged 27 May 2023

Orthophoto mosaic of Slovakia © GKÚ Bratislava, NLC Zvolen. The year and day of imaging depend on the location, so individual years may differ in season and weather.

More watercourses near the Melioračný kanál Tvrdonice watercourse

The nearest rivers, streams and water bodies in the same river basinWatercourses6

Geology at a glance and a map of the zone

What lies beneath the water and around it? An overview in tiles, a map of mine workings, deposits, environmental burdens, boreholes and gold finds, and how to read the data

The overview is based on public registers and atlases of the State Geological Institute of Dionýz Štúr. The search covers a zone around the water of all fishing districts of the stream (12 km of line in total): stream samples within 1 km, boreholes, mine workings and burdens within 3 km, ore occurrences within 5 km, geothermal sources within 10 km.

Rock under the water

River alluvium100% of the water line

Gravelly and sandy bottom and floodplains; the water is replenished from groundwater in the alluvium. Geological Map of Slovakia 1:50,000.

Water according to the atlas

pH 7.9modelled estimate

water type Ca–Na+K–HCO₃–SO₄

Mineralisation 732 mg/l, very hard water (21.3 °dH). Interpolation of measurements from the Geochemical Atlas of Slovakia, not a measurement in the stream.

Elements in river sediment

0 from 15elements in the top 10 %

highest: Cadmium 0.446 mg/kg

Position of the highest-ranked element among the sample points on streams in Slovakia: percentile 83. Interpolation of the Geochemical Atlas of river sediments.

Heat underfoot

40°C at 1,000 m depth

heat flow 52 mW/m²

At a depth of 2,000 m about 65 °C (increase of 25 °C per kilometre). Atlas of Geothermal Energy of Slovakia.

Natural gamma radiation

49nGy/h dose rate

percentile 37 in Slovakia

Natural background from rocks and soil (potassium, uranium, thorium), not a value measured at the water. Airborne gamma-ray spectrometry by ŠGÚDŠ.

Old mine workings

0objects within 3 km

No old mine working is recorded within 3 km of the water.

Gold in river sediment

0samples with gold

No gold was found in river sediment samples within 1 km of the water. The samples do not cover every stream, so this does not mean there is no gold here.

Trace elements in the stream water

2 from 9indicators in the top 5 %

highest: Copper 45.0 μg/l

Position of the highest measured value in the distribution of all surface water samples in Slovakia: percentile 99 (250 m S od obce Kopčany).

Boreholes and groundwater analyses

212boreholes within 3 km

290 water analyses nearby

Of these, 202 have an archive report from Geofond. The boreholes are hydrogeological, geological, engineering-geological and other.

Geothermal energy

–

6 geothermal and mineral water springs within 10 km.

Environmental burdens and landfills

4sites within 3 km

1 environmental burden, 3 landfills

Nearest burden: Unín – zberné naftové stredisko Cunín, 390 m from the water. Proximity does not mean that substances leak from the site into the water.

Deposits and ore occurrences

20records within 5 km

10 deposits, 10 ore occurrences

Geofond registers, the metallogenetic map and the mineral resources map.

Landslides and slope deformations

0areas within 3 km

Documented landslides in the Geofond register. A landslide into a stream can cloud the water and change the bed.

Map of the corridor

Where the nearest mine workings, deposits, burdens, geothermal boreholes and gold finds are. Groups can be switched off.

Environmental burdens 4Geothermal energy 6Mining and deposits 10Ores and metals 10Boreholes and water analyses 80

The line is the water of the fishing district, the light band is the 3 km zone in which boreholes, mine workings and burdens were searched for. The map shows the nearest objects (at most a few dozen from each register), not all of them. The points correspond to the position in the register; area objects are marked by their centre.

How to read these data

Zone and distance. The distance is measured from the line of the water to the point in the register (to the centre for areas), with an accuracy of tens of metres. Counts apply only to the zone, not to the whole catchment.
Percentile. For chemistry, the highest value is compared with all atlas samples in Slovakia. It is not a legal limit or a health risk assessment; the atlases are historical (published: surface waters 2015, groundwater 1996, river sediments 1999).
Limit of quantification. Many samples have a value at the lowest level the laboratory can determine; such results mean "below the limit". For these, the position in the distribution is an estimate.
Panning concentrates. Only samples with a find are recorded. The number of grains in a concentrate is not the gold content in grams per tonne.
Relation to water. A mine working, landfill or burden nearby proves nothing about the quality of the water in the stream. It serves as a prompt for attention and a starting point for further investigation.
Sample points. The area and raster maps of ŠGÚDŠ cannot be downloaded as points, so along the line of each fishing district the value is looked up at points roughly every 3 km. It is a sample of the line, not a continuous record; a very short section may have a single point.
Atlas rasters. The chemistry of water and sediments is an interpolation of measurements in a sampling network (Geochemical Atlas of Slovakia). The value at a point is a modelled estimate for the surroundings, not a measurement in the water. The percentile compares the average of this stream with all sample points on streams in Slovakia.
Positions and scales. The maps have different scales (1:50,000 to 1:1,000,000), so the level of detail differs between sections. A map outside its coverage means there is no area at that point, not that there is nothing there.

Data: © ŠGÚDŠ (https://www.geology.sk), downloaded 8 Nov 2026. Details in the Methodology.

Rocks, groundwater and landscape

What does the water flow over? Geological structure and age of the rocks, groundwater aquifers, relief, climate, soils and geophysical fields

Geological structure beneath the water

Which rock lies beneath the water line (Geological Map of Slovakia 1:50,000), how old it is, how thick the Quaternary cover is and in which tectonic unit the water flows. The bedrock decides the hardness of the water, the bottom, the turbidity after rain and the abundance of springs.

The points follow the water line (for a stream and a basin, fishing district after fishing district). The strip is a cross-section by distance, not a map; the width of a section corresponds to the number of points.

River alluvium100%SR 72 %

marker on the bar: share among all sample points on streams in Slovakia

River alluvium: Gravelly and sandy bottom and floodplains; the water is replenished from groundwater in the alluvium.

Geological age of the rocks

Quaternary100%

Most common rock units

System	Age	Unit	Points
Quaternary	Holocene	fluvial sediments: lithofacial undivided alluvial clays, or sandy to gravelly clays of valleys and floodplains	2×

Quaternary cover

fluvial sediments of floodplains100%SR 68 %

marker on the bar: share among all sample points on streams in Slovakia

Typical thickness of the Quaternary cover7.5m

5 – 10100%SR 20 %

marker on the bar: share among all sample points on streams in Slovakia

Tectonic division

NEOALPÍNSKE TEKTONICKÉ ŠTRUKTÚRY ZÁPADNÝCH KARPÁT100%SR 84 %

marker on the bar: share among all sample points on streams in Slovakia

Neotectonic units

positive unit (lowland hills)100%SR 14 %

marker on the bar: share among all sample points on streams in Slovakia

Direction of neotectonic movements

very small uplift67%SR 6.4 %
small uplift33%SR 7.7 %

marker on the bar: share among all sample points on streams in Slovakia

Regional geological division

intramontane basins100%SR 44 %

marker on the bar: share among all sample points on streams in Slovakia

Regional geological division (subunits)

Vienna Basin100%SR 4.0 %

marker on the bar: share among all sample points on streams in Slovakia

Engineering-geological districts

region of lowland-stream deposits100%SR 20 %

marker on the bar: share among all sample points on streams in Slovakia

Engineering-geological formations

formation of Quaternary sediments100%SR 71 %

marker on the bar: share among all sample points on streams in Slovakia

Susceptibility of the area to slope deformations

Region of stable areas100%SR 95 %

marker on the bar: share among all sample points on streams in Slovakia

The map covers 2 of 5 points on the water line.

Hydrogeology: aquifers and groundwater

Streams and rivers are fed by groundwater. Hydrogeological maps show in which rocks the water is stored, how permeable they are and what the water in them is like. The data come from ŠGÚDŠ maps, not from measurements at a particular water.

Aquifer rocks (hydrogeological map 1:200,000)

Gravel100%SR 52 %

marker on the bar: share among all sample points on streams in Slovakia

Aquifer type

Zvodnence s prevažne medzizrnovým typom priepustnosti (prevažne nespevnené sedimenty) (Gravel; Fluviálne)100%SR 27 %

marker on the bar: share among all sample points on streams in Slovakia

Type of permeability (basic hydrogeological map 1:50,000)

intergranular100%SR 86 %

marker on the bar: share among all sample points on streams in Slovakia

Hydrogeological function

aquifer100%SR 95 %

marker on the bar: share among all sample points on streams in Slovakia

Main hydrogeological region

Quaternary of the Morava up to Brodské100%SR 0.0 %

marker on the bar: share among all sample points on streams in Slovakia

Relief, climate and soils

A basin is not just water: slope and elevation determine the speed of runoff, climate the temperature and amount of water, and soils what is washed into the stream. The data come from the geomorphological division, climatic-geographical types and soil maps of ŠGÚDŠ.

Elevation of geomorphological units (from–to)148–209m a.s.l.
Average elevation of the units160m a.s.l.
Average slope0.3°
Average January temperature-2.5°C
Average July temperature20.0°C
Annual precipitation590mm

Geomorphological units

Lower Morava Valley100%SR 0.0 %

marker on the bar: share among all sample points on streams in Slovakia

Geomorphological regions

South Moravian Basin100%SR 0.5 %

marker on the bar: share among all sample points on streams in Slovakia

Climatic-geographical types

lowland climate100%SR 38 %

marker on the bar: share among all sample points on streams in Slovakia

Susceptibility of soils to acidification

soils susceptible to acidification100%SR 31 %

marker on the bar: share among all sample points on streams in Slovakia

Soil contamination (map 1:500,000)

relatively clean soil100%SR 53 %

marker on the bar: share among all sample points on streams in Slovakia

Lithogeochemical types

Neogene100%SR 48 %

marker on the bar: share among all sample points on streams in Slovakia

Geophysical fields: magnetics and gravity

Maps of the magnetic field and gravity (ŠGÚDŠ) reveal what lies beneath the sediments and the surface: volcanic bodies, faults and crustal thickness. For an angler they are interesting indirectly: they show where the bedrock changes, and with it the water.

Magnetic anomaly

+115nT

range 109 to 123 nT

Deviation of the Earth's magnetic field from its surroundings. Positive and negative anomalies reveal rocks with magnetite (basalts, basic volcanic rocks) and boundaries in the bedrock.

Bouguer gravity anomaly

-50mGal

residual −5.7 mGal

Negative values lie over thick sediments and under mountains (light crust), positive over dense rocks and thinner crust. It shows the structure of the Earth's crust, not the water.

Chemistry of water and river sediments

What is in the water and on the bed? Trace elements and metals, nutrients, major ions, elements in sediments and groundwater

Surface water chemistry according to the atlas

Modelled composition of the water in the area the fishing district line runs through. The rasters of the Geochemical Atlas of Slovakia (surface waters) are an interpolation of measurements in sampled streams, so they show the typical background of the area, not a measurement in a particular stream.

Water acidity

pH 7.87typical range

Most rivers and streams in Slovakia have a pH of 6.5 to 8.5. More acidic water is found in streams on acidic rocks (granites, quartzites), more alkaline water near limestones.

Water hardness

21.3°dH, very hard

Sum of calcium and magnesium (3.80 mmol/l). Hard water is buffered and its pH changes more slowly; soft water is more sensitive to acid rain.

Dissolved substances

732mg/l mineralisation

Total amount of dissolved minerals. Clean mountain water has tens of mg/l, lowland and limestone waters hundreds.

Ionic composition of the water

Cations (positive ions)

Ca 50Na+K 27Mg 23

Anions (negative ions)

HCO₃ 52SO₄ 32Cl 16

Water type by dominant ions: Ca–Na+K–HCO₃–SO₄

Shares are in equivalents, the usual way of comparing the composition of waters.

Major ions

SodiumNa55.1 mg/lpercentile 95
PotassiumK16.3 mg/lpercentile 95
SulphatesSO4145 mg/lpercentile 95
ChloridesCl53.9 mg/lpercentile 92
CalciumCa104 mg/lpercentile 89
MagnesiumMg29.4 mg/lpercentile 84
BicarbonatesHCO3303 mg/lpercentile 78
FluoridesF0.187 mg/lpercentile 77

dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile)

Nutrients and organic pollution

PhosphatesPO42.01 mg/lpercentile 95
AmmoniumNH43.90 mg/lpercentile 95
Chemical oxygen demandChSK8.75 mg/lpercentile 95
NitratesNO319.3 mg/lpercentile 91

Metals

ZincZn21.5 μg/lpercentile 88
ManganeseMn80.5 μg/lpercentile 75
IronFe0.146 mg/lpercentile 64
AluminiumAl33.1 μg/lpercentile 31

Trace elements in surface waters

Arsenic, antimony, cadmium, lead, copper, zinc and other elements in samples from rivers and streams (Geochemical Atlas of Slovakia, surface waters, 2015). The bar shows where the highest value lies among all samples in Slovakia; the light marker is the median of the samples at this water.

CopperCuextreme (top 1 %)
highest 45.0 μg/lmedian 1.60 μg/l7 samples
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: 250 m S od obce Kopčany2002, 290 m from the water. Comparison: percentile 99 of all samples in Slovakia.
AntimonySbhigh (top 5 %)
highest 4.00 μg/lmedian 0.500 μg/l7 samples86 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: Morava2003, 840 m from the water. Comparison: percentile 95 of all samples in Slovakia.
LithiumLielevated (top 10 %)
highest 38.0 μg/lmedian 11.0 μg/l7 samples43 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: 250 m S od obce Kopčany2002, 290 m from the water. Comparison: percentile 93 of all samples in Slovakia.
BariumBaelevated (top 10 %)
highest 105 μg/lmedian 54.0 μg/l7 samples
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: Tvrdonice, kanál2003, 40 m from the water. Comparison: percentile 92 of all samples in Slovakia.
ArsenicAstypical value
highest 1.00 μg/lmedian 1.00 μg/l7 samples43 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: Tvrdonice, kanál2003, 40 m from the water. Comparison: percentile 50 of all samples in Slovakia.
SeleniumSebelow half of Slovakia
highest 0.500 μg/lmedian 0.500 μg/l7 samples100 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: Bez mena2004, 890 m from the water. Comparison: percentile 46 of all samples in Slovakia.
LeadPbbelow half of Slovakia
highest 2.50 μg/lmedian 2.50 μg/l7 samples100 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: Bez mena2004, 890 m from the water. Comparison: percentile 43 of all samples in Slovakia.
ChromiumCrbelow half of Slovakia
highest 1.00 μg/lmedian 1.00 μg/l7 samples100 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: Bez mena2004, 890 m from the water. Comparison: percentile 32 of all samples in Slovakia.
CadmiumCdbelow half of Slovakia
highest 0.150 μg/lmedian 0.150 μg/l7 samples100 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: Bez mena, 890 m from the water. Comparison: percentile 26 of all samples in Slovakia.

Major ions, mineralisation and pH

Basic water chemistry: which rocks the minerals in it come from.

Silicon dioxideSiO2typical value
highest 16.9 mg/lmedian 5.19 mg/l7 samples
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: 250 m S od obce Kopčany2002, 290 m from the water. Comparison: percentile 71 of all samples in Slovakia.

Elements in river sediments

The Geochemical Atlas of Slovakia (river sediments) describes what the river carries in the fine material on its bed. Sediment collects metals from rocks, ore occurrences and past mining and industry. It is not a legal limit or a health risk assessment: it shows how an element on this stream ranks among streams in Slovakia.

Potentially toxic and trace elements

CadmiumCd0.446 mg/kgpercentile 83
ChromiumCr95.1 mg/kgpercentile 78
ZincZn127 mg/kgpercentile 72
MercuryHg0.178 mg/kgpercentile 71
SeleniumSe0.327 mg/kgpercentile 67
CopperCu26.8 mg/kgpercentile 62
CobaltCo8.57 mg/kgpercentile 52
ArsenicAs6.61 mg/kgpercentile 50
NickelNi23.7 mg/kgpercentile 46
MolybdenumMo0.351 mg/kgpercentile 45
LeadPb14.6 mg/kgpercentile 44
BismuthBi0.195 mg/kgpercentile 40
TinSn2.29 mg/kgpercentile 34
VanadiumV53.6 mg/kgpercentile 15
AntimonySb0.283 mg/kgpercentile 9

dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile)

Major elements (iron, aluminium, calcium, magnesium, potassium, sodium, titanium, manganese, phosphorus)

PhosphorusP1,729 mg/kgpercentile 95
ManganeseMn1,097 mg/kgpercentile 72
PotassiumK1.51 %percentile 49
CalciumCa1.82 %percentile 44
IronFe2.36 %percentile 30
AluminiumAl4.53 %percentile 12
MagnesiumMg0.590 %percentile 12
TitaniumTi3,231 mg/kgpercentile 9
SodiumNa0.600 %percentile 8

Further elements (barium, strontium, lithium, rubidium, zirconium, yttrium, cerium, boron, beryllium, gallium)

GalliumGa18.8 mg/kgpercentile 86
BariumBa440 mg/kgpercentile 51
RubidiumRb88.1 mg/kgpercentile 49
ZirconiumZr398 mg/kgpercentile 49
StrontiumSr127 mg/kgpercentile 41
BerylliumBe1.11 mg/kgpercentile 33
CeriumCe53.0 mg/kgpercentile 28
LithiumLi25.8 mg/kgpercentile 27
BoronB43.5 mg/kgpercentile 14
YttriumY18.4 mg/kgpercentile 11

Groundwater: chemistry and water types

Hydrogeochemical objects (analyses of springs and boreholes) and the geochemical atlas of groundwater (1996). Groundwater feeds streams, so its composition also affects the water in the stream.

Metals in groundwater

ChromiumCrextreme (top 1 %)
highest 65.0 μg/lmedian 0.250 μg/l23 samples65 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 380 m from the water. Comparison: percentile 99 of all samples in Slovakia.
SeleniumSeextreme (top 1 %)
highest 8.50 μg/lmedian 0.500 μg/l23 samples65 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 1.7 km from the water. Comparison: percentile 99 of all samples in Slovakia.
CopperCuextreme (top 1 %)
highest 21.0 μg/lmedian 3.90 μg/l23 samples
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 1.7 km from the water. Comparison: percentile 99 of all samples in Slovakia.
LeadPbhigh (top 5 %)
highest 7.00 μg/lmedian 1.00 μg/l23 samples30 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: vrt1993, 1.1 km from the water. Comparison: percentile 98 of all samples in Slovakia.
ZincZnhigh (top 5 %)
highest 2,646 μg/lmedian 240 μg/l23 samples
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 2.3 km from the water. Comparison: percentile 97 of all samples in Slovakia.
LithiumLihigh (top 5 %)
highest 86.0 μg/lmedian 20.0 μg/l23 samples
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: vrt1993, 320 m from the water. Comparison: percentile 97 of all samples in Slovakia.
ArsenicAshigh (top 5 %)
highest 8.70 μg/lmedian 0.500 μg/l23 samples65 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 1.8 km from the water. Comparison: percentile 97 of all samples in Slovakia.
MercuryHghigh (top 5 %)
highest 0.300 μg/lmedian 0.100 μg/l23 samples78 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 1.1 km from the water. Comparison: percentile 96 of all samples in Slovakia.
CadmiumCdhigh (top 5 %)
highest 0.600 μg/lmedian 0.250 μg/l23 samples91 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 2.3 km from the water. Comparison: percentile 95 of all samples in Slovakia.
AntimonySbhigh (top 5 %)
highest 0.700 μg/lmedian 0.100 μg/l23 samples61 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 930 m from the water. Comparison: percentile 95 of all samples in Slovakia.
AluminiumAlslightly elevated
highest 0.0100 mg/lmedian 0.00500 mg/l23 samples96 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 820 m from the water. Comparison: percentile 75 of all samples in Slovakia.
IronFetypical value
highest 0.00500 mg/lmedian 0.00500 mg/l13 samples100 % below the limit of quantification
1. up to 50 %
2. 50–75
3. 75–90
4. 90–99
5. above 99
Highest value: studňa1993, 1.8 km from the water. Comparison: percentile 50 of all samples in Slovakia.

Gold, mines and deposits

Was gold panned and ore mined here? Gold and ore minerals in river sediments, old mine workings, deposits and ore occurrences

Mine workings, deposits and ore occurrences

Old mine workings outside mining areas (Geofond register), deposits and mining areas, and the metallogenetic map. Gold, silver and other metals near streams can get into sediments and water.

Deposits and mining areas

CunínMineralcombustible natural gasStatus and organisationDeposit with halted mining or where use of reserves is not expected – NAFTA a.s.
60 m
CunínMineralsemi-paraffinic crude oilStatus and organisationDeposit with halted mining or where use of reserves is not expected – NAFTA a.s.
60 m
CunínMineralsemi-paraffinic crude oilStatus and organisationDeposit with halted mining or where use of reserves is not expected – NAFTA a.s.
60 m
CunínMineralcombustible natural gasStatus and organisationDeposit with halted mining or where use of reserves is not expected – NAFTA a.s.
60 m
Gbely – AdamovMineralgravelly sands and sandsStatus and organisationMined deposit – Poľnohospodárske družstvo Gbely, a.s.
220 m
Kopčany – VrbovéMineralgravelly sands and sandsStatus and organisationMined deposit – SAZAN, spoločnosť s ručením obmedzeným
1.1 km
Gbely B – poleMineralcombustible natural gasStatus and organisationDeposit with halted mining or where use of reserves is not expected – NAFTA a.s.
2.3 km
Gbely B – poleMineralnon-paraffinic crude oilStatus and organisationDeposit with halted mining or where use of reserves is not expected – NAFTA a.s.
2.3 km
GbelyMineralnon-paraffinic crude oilStatus and organisationDeposit, where geological exploration is under way – NAFTA a.s.
3.9 km
GbelyMineralnon-paraffinic crude oilStatus and organisationDeposit, where geological exploration is under way – NAFTA a.s.
4.4 km

Geothermal energy, mineral waters and boreholes

Is there heat underground? Geothermal potential, geothermal boreholes by temperature, mineral springs and the borehole archiveBoreholes212

Geothermal potential

The Atlas of Geothermal Energy of Slovakia records rock temperature and heat flow from the Earth's interior. It is the potential of the area, not the actual warmth of the water in the stream. Specific geothermal boreholes and springs near this water are in the geothermal energy section below.

Rock temperature with depth

40 / 65 °Cat depths of 1,000 and 2,000 m

increase of 25 °C per km

The line shows the rock temperature; the dotted part is only an extension to the surface. Heat flow 52 mW/m².

Geothermal energy and mineral waters

Geothermal boreholes (wellhead water temperature, yield, chemical type) and sources of geothermal and mineral waters within 10 km. Data on the use and existence of a borehole come from the Geofond register.

Sources of geothermal and mineral waters

category a1Typemineral waterWater temperature (°C)< 15Yield (l/s)< 5Count4
2.7 km
category GbelyTypethermal bathsCount1
5.8 km
category b1Typemineral waterWater temperature (°C)15-22Yield (l/s)< 5Count1
7.8 km

Boreholes and Geofond archive reports

Register of hydrogeological boreholes, other boreholes and geothermal boreholes. Each borehole has a report in the Geofond archive (geological profiles, pumping tests, chemical analyses of the water); the report number is in the table.

212 boreholes in the 3 km zone, of which 116 hydrogeological and 96 other; with an archive report number 202.

Borehole depths

up to 10 m133×
10–30 m45×
30–100 m7×
100–300 m7×
over 300 m14×

Nearest boreholes

V-1Typeengineering-geologicalDepth3.0 mArchive report83729
30 m
P-15TypehydrogeologicalDepth8.5 mArchive report46494
50 m
Kopčany-Boričky II.Typewide-diameter boreholeDepth10.0 mArchive report63598 119Ca13.pdf
90 m
KopčanyTypenarrow-diameter borehole with ordinary drinking and process waterDepth7.2 mArchive report25664 119Ca7.pdf
100 m
VN95-5TypeenvironmentArchive report96444
100 m
V-2Typeengineering-geologicalDepth3.0 mArchive report83729
140 m
KopčanyTypemonitoring boreholeDepth7.1 mArchive report46494 119Ca75.pdf
150 m
Kopčany-Boričky II.Typewide-diameter boreholeDepth10.0 mArchive report63598 119Ca14.pdf
150 m
P-30TypehydrogeologicalDepth7.1 mArchive report46494
150 m
KopčanyTypemonitoring boreholeDepth6.8 mArchive report46494 119Ca67.pdf
170 m
P-22TypehydrogeologicalDepth6.8 mArchive report46494
170 m
KopčanyTypewide-diameter boreholeDepth9.0 mArchive report44353 119Ca12.pdf
180 m

Natural radioactivity and radon

How much does the ground radiate here? Gamma radiation of rocks, radon in soil and radon in waters

Natural radioactivity and radon

Airborne gamma-ray spectrometry by ŠGÚDŠ measures radiation from potassium, uranium and thorium in rocks and soil. Granites and some acidic volcanic rocks have the highest values, limestones and floodplains the lowest. Caesium-137 is a remnant of fallout from the Chernobyl accident and nuclear weapons tests.

Gamma radiation dose rate

49nGy/h in air

range 47 to 50 nGy/h

Natural background from rocks and soil; higher over granites and some acidic volcanic rocks, lower over limestones and floodplains.

Radon risk of the bedrock

low

Radon is a natural gas from rocks. The risk concerns buildings and cellars, not the water in the stream; it shows what the bedrock is like.

Equivalent thorium (eTh)eTh7.52 ppm56th percentile
Potassium (K)K1.29 %percentile 43
Equivalent uranium (eU)eU2.27 ppm19th percentile

dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile)

Areal activity of 137CsCS1371,187 Bq/m²percentile 30

Radon risk by isopleths

low67%SR 36 %
medium33%SR 64 %

marker on the bar: share among all sample points on streams in Slovakia

Radon in waters

Radiohydrochemical sampling of springs, wells and watercourses: radon activity concentration in water. The bar shows the highest measured value for each kind of site.

well15.8 Bq/l · median 5.14 Bq/l · 7 samples
free-flowing borehole8.21 Bq/l · median 5.97 Bq/l · 2 samples
water source for public supply3.36 Bq/l · median 3.36 Bq/l · 1 sample
stream, river0.840 Bq/l · median 0.840 Bq/l · 1 sample
reservoir0.520 Bq/l · median 0.520 Bq/l · 1 sample

Environmental burdens, landfills and landslides

What in the surroundings can harm the water? Environmental burdens, waste landfills, anthropogenic sediments and slope deformationsBurdens and landfills4

Environmental burdens, landfills and anthropogenic sediments

Recorded environmental burdens (industrial sites, landfills, mining), the register of waste landfills and monitoring of anthropogenic sediments (industrial sludge). It is a list of places, not a measurement of water pollution.

Environmental burdens

Unín – zberné naftové stredisko CunínActivitySK1000100P
390 m

Waste landfills

KopčanyArea18 000 m²Year established1988Monitoring–
100 m
KopčanyArea250 m²Year established1986Monitoring–
190 m
( Gbely – Zadný diel) – GbelyArea600 m²Year established1961Monitoring–
1.5 km

The Melioračný kanál Tvrdonice watercourse at a glance

Today on the Melioračný kanál Tvrdonice watercourse

Average of the watercourse's fishing districts

Best window today

Map and fishing districts of the Melioračný kanál Tvrdonice watercourse

Fish and catches on the Melioračný kanál Tvrdonice watercourse

Game species recorded in the fishing district

Anglers' catches

Organizations and districts on the Melioračný kanál Tvrdonice watercourse

Organizations on the watercoursewho manages the fishing districts and what the conditions are there today

Water pollution on the Melioračný kanál Tvrdonice watercourse

Groundwater: measured valuestypical value from stations within 10 km, 2025

Terrain and satellite images of the Melioračný kanál Tvrdonice watercourse

Elevation profile of the watercourse

Historical images

More watercourses near the Melioračný kanál Tvrdonice watercourse

Štrkovisko Unín

Štrkovisko Boričky I.

Štrkovisko Boričky II.

Štrkovisko Adamov

Štrkovisko Holíč

Farská voda

Geology and geochemistry of the Melioračný kanál Tvrdonice stream

Geology at a glance and a map of the zone

Rock under the water

Water according to the atlas

Elements in river sediment

Heat underfoot

Natural gamma radiation

Old mine workings

Gold in river sediment

Trace elements in the stream water

Boreholes and groundwater analyses

Geothermal energy

Environmental burdens and landfills

Deposits and ore occurrences

Landslides and slope deformations

Map of the corridor

How to read these data

Rocks, groundwater and landscape

Geological structure beneath the water

Geological age of the rocks

Most common rock units

Quaternary cover

Tectonic division

Neotectonic units

Direction of neotectonic movements

Regional geological division

Regional geological division (subunits)

Engineering-geological districts

Engineering-geological formations

Susceptibility of the area to slope deformations

Hydrogeology: aquifers and groundwater

Aquifer rocks (hydrogeological map 1:200,000)

Aquifer type

Type of permeability (basic hydrogeological map 1:50,000)

Hydrogeological function

Main hydrogeological region

Relief, climate and soils

Geomorphological units

Geomorphological regions

Climatic-geographical types

Susceptibility of soils to acidification

Soil contamination (map 1:500,000)

Lithogeochemical types

Geophysical fields: magnetics and gravity

Magnetic anomaly

Bouguer gravity anomaly

Chemistry of water and river sediments

Surface water chemistry according to the atlas

Water acidity

Water hardness

Dissolved substances

Ionic composition of the water

Major ions

Nutrients and organic pollution

Metals

Trace elements in surface waters

Major ions, mineralisation and pH

Elements in river sediments