Fishing district

Lakšár

CarpNo. 1-0340-1-1LakšárDanube basin
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Fishing district boundaries: Potok Lakšár od ústia po pramene a melioračný kanál od ústia do Moravy po hranicu k. ú. Závod.

fishing district length
24.0km
district
Malacky
region
Bratislava Region
Aerial image of fishing district Lakšár with the line highlighted
Blue line: course of the fishing district (approximate). Orthophoto mosaic of Slovakia © GKÚ Bratislava, CC BY 4.0Google Maps

By the water now

Fishing conditionsFish activity indexOur calculation (0–100): the base is set by water temperature, adjusted by light, turbidity, oxygen, weather and other factors according to how well they are supported by studies. For each factor you can see the confidence and the source. A planning aid, not a bite forecast.

The score, the best window of the day and what pushes it up or down

Fishing conditions

Fish activity indexOur calculation (0–100): the base is set by water temperature, adjusted by light, turbidity, oxygen, weather and other factors according to how well they are supported by studies. For each factor you can see the confidence and the source. A planning aid, not a bite forecast.

Loading data…

Water

Water level, temperature, modelled flow and gradient

Elevation profile of the watercourse

Elevation profileHow the altitude of the watercourse changes downstream. It is calculated from a digital relief model (tens of metres), not from a water-level measurement, so it is approximate, especially for narrow streams.

Gentle gradient The current is noticeable, with shallows and slacks alternating. A transition between a lowland and a foothill watercourse.

1401601802002200 km5 km10 km15 km20 km
Elevation profile of the fishing district downstream: from 209 to 149 m a.s.l. over 24.0 km.
Downstream, from the upper end of the fishing district (left) to the lower end
Highest point
209 m a.s.l.
Lowest point
146 m a.s.l.
FallFallThe difference in altitude between the upper and lower end of the fishing district in metres. The greater the fall over a shorter length, the faster the water.
64 m
SlopeWatercourse gradientFall per kilometre in per mille (‰, metres per kilometre). Up to 2 ‰ is a slow lowland river, 5 to 10 ‰ a foothill river (grayling, trout), above 10 ‰ a fast stream.
2.7 ‰
SinuositySinuosityThe length of the watercourse divided by the straight-line distance between its ends. 1.0 is a straight watercourse; above 1.3 it meanders strongly. Meanders create pools under the banks and shallows in the reaches between.
1.25
Source: Open Topo Data (eudem25m)Updated 4 Nov 2026 11:02

Weather and forecast

Hour by hour, pressure and the next few days

Weather and forecast

Loading data…

Sky: sun, moon and solunar windowsSolunar periodsCalculated from the position of the Moon: major periods (about 2 h) around the Moon's passage above and below the horizon, minor periods (about 1 h) around moonrise and moonset. A scientifically unconfirmed theory: in a study of 361 fishing trips (Quigley et al. 2023) it did not predict bites. We treat it as a hypothesis with a weight of at most ±2 points.

Where the sun and moon are right now and when the best windows of the day will come

Sky: sun and moon

Solunar periodsCalculated from the position of the Moon: major periods (about 2 h) around the Moon's passage above and below the horizon, minor periods (about 1 h) around moonrise and moonset. A scientifically unconfirmed theory: in a study of 361 fishing trips (Quigley et al. 2023) it did not predict bites. We treat it as a hypothesis with a weight of at most ±2 points.

Drag along the axis to see where the sun and moon will be.

  • Sun
  • Moon
  • Golden hour
  • Main period
  • Minor period

Sun

  • Dawn06:17
  • Sunrise06:50
  • Sunset16:20
  • Dusk16:54

The day lasts 9 h 30 min.

MoonMoon phaseAt full and new moon the gravitational effect is strongest. On a clear full-moon night predators and carp often feed at night, and the day after may be weaker.

Nov0% illuminated
  • Moonrise07:14
  • Moonset15:50

Full moon around 24 Nov, new moon around 9 Nov.

Windows of the daySolunar periodsCalculated from the position of the Moon: major periods (about 2 h) around the Moon's passage above and below the horizon, minor periods (about 1 h) around moonrise and moonset. A scientifically unconfirmed theory: in a study of 361 fishing trips (Quigley et al. 2023) it did not predict bites. We treat it as a hypothesis with a weight of at most ±2 points.

  • Main solunar period22:12–00:12
  • Golden hour (morning)06:20–07:50
  • Minor solunar period06:44–07:44
  • Main solunar period10:36–12:36
  • Minor solunar period15:20–16:20
  • Golden hour (evening)15:20–16:50
  • Main solunar period23:01–01:01

Solunar theory is not scientifically confirmed; we treat it as a supplement. The golden hour is the time around sunrise and sunset, when fish often bite.

Map and fishing district data

Course of the water, spots along the water, character and basic data

48.57058, 17.03076 OpenStreetMap

The line shows the course of the fishing district according to the "Rybárske revíry" data 2026. Verify access points and exact boundaries on site.

Fishing district details

Fishing district user
SRZ
Organization
MO SRZ Malé Leváre – Veľké Leváre (Local SRZ organization)
Area
Bratislavská
Purpose
Fishing district
Minimal stocking
K2 50 kg, Š2 10 kg
Nature conservation
protection level 5

Characteristics

  • DepthDepthThe greatest depth from the fishing district description. Shallows warm up quickly and are rich in food; deep pools give shelter and a more stable temperature. 0.5–2.0 m
  • BottomBottomThe bottom material determines which fish live here and where they find food. Fish zones can be recognized by the bottom: rocky, gravelly, sandy to muddy. muddy
  • Watercourse lineWatercourse lineThe shape of the watercourse seen from above. In bends there is a deep scour under the outer bank and a shallow bar under the inner one; a winding stream has more shelter and changes in depth. slightly undulating
  • ShadingShadingThe share of the water surface in shade. Shade lowers summer water temperatures and supplies insects and shelter; a sunny section warms up faster and becomes more overgrown. 60%
  • VegetationVegetationTree and herbaceous vegetation on the banks. Roots and branches create shelter, and leaves and twigs falling in provide food. It also determines where you can cast and where your rig gets snagged. alder, willow, poplar
  • Cross-channel structuresCross-channel structuresWeirs, steps and dams hold back water and stop fish from migrating. Below them a deep plunge pool with oxygenated water forms. none
What this means for anglersexplanation of the bottom, vegetation, watercourse line and other data of this fishing district
  • Depth: Medium, 1–3 m

    The most common type: shallows alternate with deeper spots and fish move according to the time of day and temperature.

  • Bottom: Muddy bottom

    Slow lowland waters and carp fishing districts. Mud hides food, but in summer there may be less oxygen near the bottom, and lures sink into it.

  • Watercourse line: Slightly undulating line

    Gentle bends: on one section you will find both deeper scours and shallower bars.

  • Shade: Shady, 41–70%

    In summer the water is cooler, with more insects falling in and more shelter. It is often a good place for trout and grayling.

  • Vegetation: Willow

    Grows by the water; the roots stabilize the bank and create shelters beneath the surface. The branches hang over the water and provide shade and insects.

  • Vegetation: Alder

    A typical tree of stream and river banks. A dense root system creates undercut banks and shelters, and the leaves decompose quickly.

  • Vegetation: Poplar

    Tall, fast-growing trees. They provide shade and insects, and branches and leaves fall into the water.

  • Cross-channel structures: none

    Fish can move freely along the watercourse; the section is more continuous.

The explanation is general and based on the fishing district description in the data and on common fishing practice. Actual conditions on site may differ; check them before you fish.

Confluences and risk spots

  • COV Moravsky Svaty JanWastewater discharge point
    0.0 km
  • COV Moravsky Svaty JanWastewater treatment plant · capacity 4,500 PE
    Details
    Load
    3,271 of 4,500 PE (73%)
    Treatment
    mechanical, biological
    Meets the requirements
    BOD₅, COD
    1.9 km

Spots within 3 km of the watercourse are shown.

Source: VÚVH (CC BY 4.0)Updated 9 Nov 2026 15:43

Law and fishing rules

Closed season, fishing hours, minimum sizes and daily limit. For guidance only: check them in the fishing regulations of the fishing district

Closed season for all fish

§ 13, paragraphs 3 and 5 of the Act

15 Mar – 31 May

fishing for all fish prohibitedoutside this period

The ban does not apply 1 May – 31 May during fishing competitions (§ 13, para. 3). It also does not apply to carp waters that are watercourses (but not reservoirs, dead-end, dead and cut-off arms), or to other water bodies (§ 13, para. 5). Check in the fishing regulations of the district which case your district is.

The protection periods by species (below) apply independently of this closed season.

Daily fishing hours

§ 11 of the Decree

Applies only outside the closed season. Outside these hours fishing is prohibited (§ 14(b) of the Act).

January to April, November, December6.00 – 21.00 h

May4.00 – 24.00 h

June to October0.00 – 24.00 h

Months missing from the table fall within the closed season. The hours in November and December on trout and grayling waters relate to the exception for fishing huchen (§ 13, para. 4 of the Act); check in the fishing regulations what may be caught at that time. On border waters the hours in the permit or the fishing regulations apply (§ 11, para. 2 of the Decree). The Act regulates night fishing in two wordings that seem to contradict each other at first sight, so always ask about it in the fishing regulations of the district or the fishing guard.

Rods, baits and fishing days

§ 18 of the Act
Number of rods
at most 2
Permitted methods
bottom fishing, float fishing, spinning, fly fishing
Hooks and baits
on a rod at most 2 hooks (bottom fishing, float fishing), artificial lure at most 3 hooks, a hook at most 3 points, fly fishing at most 3 flies
Live or dead baitfish
prohibited 15 Mar – 31 May; otherwise at least 10 cm and above the minimum size
Fishing days of the week
the law specifies no restriction
Ice fishing
prohibited (watercourses, reservoirs, arms)
Other
spinning and fly fishing with a fish imitation prohibited 15 Mar – 31 May; fishing from a boat prohibited on reservoirs 1 Jan – 31 May

This is a summary. For baits, hooks and groundbait also read the fishing regulations of the district, because the user may tighten the conditions.

How many fish you may keep per day

§ 14 of the Decree
  • 1pcsBlue groupsterlet, Siberian sturgeon, wels catfish
  • 2pcsGreen groupeel, carp, burbot, zander, pike, tench, barbel, lake brown trout, brown trout, grayling (combined)
  • 4pcsYellow grouprainbow trout, brook trout, common nase, vimba bream; added to the green or blue group (at most 4 fish in total)
  • 5kgOther speciesfor example crucian carp, breams, dace and chub (combined); invasive species are not counted

The blue and green groups cannot be combined. The limit applies per day, also when fishing in several districts, and once it is reached, fishing for that day ends. The species groups follow the SRZ interpretation of January 2026, not the text of the section directly. The district user may set a lower limit in the permit, in which case the stricter one applies.

Protection periods by species§ 10 of the Decree

During this period the species must not be caught, even if the water type otherwise allows fishing at that time. It applies independently of the closed season for all fish.

1 Jan – 15 Mar
burbot
1 Jan – 31 May
grayling, spirlin, northern pike
1 Jan – 15 Jun
wels catfish, zander (pikeperch), Volga pikeperch
1 Jan – 31 Oct
huchen (in border waters 1 Jan – 31 Aug)
15 Mar – 31 May
common carp in carp waters (does not apply 1 – 31 May during competitions, nor on other water bodies); asp, chub, dace, ide, sterlet, Siberian sturgeon, tench, barbel, vimba bream, zope, white-eye bream, common bream, common nase
1 Sep – 15 Apr
brown trout, brown trout (lake form)
1 Sep – 28 Feb
peled

Some species are protected all year round (for example zingel and streber, lampreys, gudgeons, spined loaches, maraena whitefish, Carpathian barbel, sabre carp) and fishing for them is always prohibited. The full list of species is in the guide The fishing law, rule by rule.

Minimum sizes§ 12 of the Decree

The shortest length from which you may keep a fish. The district user may raise the size, so look for the valid value in the permit and the fishing regulations.

  • grass carp60 cm
  • black carp60 cm
  • asp40 cm
  • huchen (Danube salmon)80 cm
  • chub25 cm
  • dace20 cm
  • ide30 cm
  • sterlet45 cm
  • Siberian sturgeon45 cm
  • common carp40 cm
  • tench30 cm
  • grayling33 cm
  • burbot35 cm
  • barbel40 cm
  • vimba bream30 cm
  • zope (blue bream)25 cm
  • white-eye bream25 cm
  • common bream30 cm
  • silver bream15 cm
  • common nase30 cm
  • rainbow trout27 cm
  • brown trout (lake form)50 cm
  • brown trout27 cm
  • peled25 cm
  • brook trout27 cm
  • wels catfish70 cm
  • northern pike60 cm
  • silver carp45 cm
  • bighead carp45 cm
  • European eel50 cm
  • zander (pikeperch)50 cm
  • Volga pikeperch35 cm

Total length is measured from the front of the head to the end of the longest ray of the tail fin (§ 12, para. 4). No minimum size applies, for example, to sunbleak, Prussian carp, European perch, roach, stone loach and invasive species.

Before and after fishing

  • Carry your fishing license and permit while fishing and show them when checked (§ 12 of the Act). Check that they are valid.
  • Before you start fishing, write down the date and the district number (no. 1-0340-1-1); after fishing, write down the number and weight of your catch (§ 14(d) of the Act). Fishing without a record is an offense.
  • Prohibited fishing methods, night fishing, competitions and other rules are covered in the guide The fishing law, rule by rule.

As of 6 Nov 2026: Act no. 216/2018 Coll. on fisheries (wording effective 1 Jan 2022) and Decree no. 381/2018 Coll. (wording effective 1 Jan 2019); we found no newer wording. The law may change; you can find the current wording on Slov-Lex (Act) and Slov-Lex (Decree).

News from the organization and catches from the fishing district

Catches from the fishing district

Nobody has recorded a catch in this fishing district yetBe the first: after approval it will also appear here in the ranking.

Terrain in 3D

Loading the 3D terrain model…

Water according to public sources

Water quality, river basin, bottom, fish, aquatic insects, wildlife and hazards from open databases. Except for wildlife and hazards, they are also included in the activity score.

Water suitability for the fishing district type

Water suitability for the district typeIndex 0 to 100: how well the properties of the water match the needs of trout, grayling or carp, depending on the district type. It is not a bite forecast or a statement about which fish live there.
83from 100
The most suitable water for carp and cyprinids

The water is in the top 16% of 897 carp fishing districts with data.

  • Best fit: water acidity (pH)

Reliability medium: we used 5 water data points; the rest are missing and are not part of the assessment.

  • Stream zoneLevel of evidence: Partly supported

    gradient 2.7 ‰, 177 m a.s.l. → barbel zone

    Based on gradient and elevation, the stream lies in an area that corresponds to the barbel zone. This is a natural zone for carp and cyprinids.

    What we know about it

    European streams are divided from source to mouth into zones with typical fish: trout, grayling, barbel and lowland; they are determined mainly by gradient and stream size (Huet 1959), and the zones can also be used to assess the condition of streams (Aarts and Nienhuis 2003). We estimate the zone from the gradient of the fishing district's line and its elevation; it is a simplification without stream width. A match between the zone and the fishing district type adds +1 to quality, a clear mismatch −1.

    Sources: Huet 1959; Aarts and Nienhuis 2003

    78
  • Water hardnessLevel of evidence: Hypothesis

    ≈ 14.7 °dH (2.6 mmol/l of calcium and magnesium), ŠGÚDŠ atlas

    Harder water with enough calcium and magnesium is more productive, has a larger food supply and buffers acidity swings better.

    What we know about it

    Water with calcium and magnesium is more productive and buffers acidity swings better: trout production was higher in calcareous hard waters (Almodóvar et al. 2006), and an index based on dissolved solids and depth predicts fish yield from lakes (Ryder et al. 1974). In Irish streams, however, geology did not change trout density (Lehane et al. 2004), and Downing et al. (1990) showed that production is related rather to primary production. Hence only ±1 point. Hardness comes from the ŠGÚDŠ atlas, not from a measurement in the fishing district; it replaces the separately assessed bedrock of the basin.

    Sources: Almodóvar et al. 2006; Lehane et al. 2004; Ryder et al. 1974

    95
  • Water acidity (pH)Level of evidence: Partly supported

    pH 7.7, ŠGÚDŠ atlas

    The pH is within the range in which fish commonly thrive.

    What we know about it

    Below about pH 6 fish suffer, and trout and grayling are more sensitive than cyprinids (Alabaster and Lloyd 1982); in acidic soft water, aluminium is released from the soil and damages gills (Gensemer and Playle 1999). The pH from the atlas is a model estimate, so the reduction is only −1 or −2, and only where we have no pH measurement (which is assessed by a separate factor).

    Sources: Alabaster and Lloyd 1982; Gensemer and Playle 1999

    100
  • MineralizationLevel of evidence: Hypothesis

    ≈ 480 mg/l, ŠGÚDŠ atlas

    Medium mineralisation corresponds to productive streams and reservoirs.

    What we know about it

    Dissolved solids (mineralisation) are related to the fertility of the water, which is why Ryder used them to estimate fish production in lakes (Ryder 1965, Ryder et al. 1974). Downing et al. (1990) showed, however, that primary production is a better predictor of production. It does not enter the score, only the suitability index.

    Sources: Ryder 1965; Ryder et al. 1974; Downing et al. 1990

    99
  • Metals in sedimentLevel of evidence: Partly supported

    0 elements among the highest 10 % in Slovakia (ŠGÚDŠ atlas 1999)

    None of the toxic elements in river sediment is among the highest values. In hard water metals are less toxic, because calcium competes for sites on the gills.

    What we know about it

    The toxicity of metals to fish decreases with water hardness, because calcium competes with the metal for sites on the gills (Pagenkopf 1983). The ŠGÚDŠ atlas gives only the rank among streams, not a concentration comparable with a limit (MacDonald et al. 2000). In hard water we therefore rate metals more leniently, in soft water more strictly.

    Sources: Pagenkopf 1983; Gensemer and Playle 1999; MacDonald et al. 2000

    100

How this water would suit each type

  • Trout62
  • Grayling75
  • Carp83

The same water data evaluated against the requirements of trout, grayling and carp. The fishing district is registered as a carp district; its type is highlighted.

The index 0 to 100 compares the properties of the water with the requirements of the species (60 is the neutral value, 100 the ideal). The verbal rating comes from comparison with other fishing districts of the same type, because most Slovak waters have good values for their species. The index does not affect whether fish really occur in the fishing district (that is decided by stocking and the manager). Hardness, pH and mineralisation from the atlases are historical and model estimates. Only a small part of this feeds into the conditions score and fishing district quality (hardness ±1, atlas acidity −2 to 0, stream zone match ±1 to quality).

What follows from this

Public sources in the conditions scoreData on oxygen, nutrients, reservoir depth, watercourse size, bottom, fish species and insect swarming slightly adjust the "Fishing conditions" score. Each adjustment is shown separately in the score breakdown.
−14−40+4+12−4
Public data about this water lower the activity score.
  • Biggest boost: Water hardness +1
  • Biggest deduction: Harmful substances in groundwater (SHMÚ) −2

We assessed 17 factors; 6 of them change the score. The adjustments range from −14 to +12 points so that they do not outweigh the weather and water temperature. They are counted in the score, in the ranking and in the filters.

Water and oxygen+1

  • Water hardnessLevel of evidence: Hypothesis

    ≈ 14.7 °dH, ŠGÚDŠ atlas

    Harder water is more productive, has more food and buffers acidity swings better.

    What we know about it

    Water with calcium and magnesium is more productive and buffers acidity swings better: trout production was higher in calcareous hard waters (Almodóvar et al. 2006), and an index based on dissolved solids and depth predicts fish yield from lakes (Ryder et al. 1974). In Irish streams, however, geology did not change trout density (Lehane et al. 2004), and Downing et al. (1990) showed that production is related rather to primary production. Hence only ±1 point. Hardness comes from the ŠGÚDŠ atlas, not from a measurement in the fishing district; it replaces the separately assessed bedrock of the basin.

    Sources: Almodóvar et al. 2006; Lehane et al. 2004; Ryder et al. 1974

    +1

Pollution−4

  • Nitrogen in groundwater (SHMÚ)Level of evidence: Partly supported

    nitrates typically 0.5 mg/l (standard 50), ammonium above the standard at 2 of 8 stations

    Groundwater reaches streams as base flow and carries nitrogen from fields and waste. Nitrates feed algae and contribute to nighttime oxygen crashes; nitrites are toxic to fish. Nitrites and ammonium can also be natural in deep groundwater, so at most one point is deducted for them. The data reliability is 100% (8 stations within 10 km, nearest 1 km, data from 2025), and the adjustment was applied in full.

    What we know about it

    Groundwater reaches streams as base flow. The typical nitrate value from stations within 10 km (moderate from 25 mg/l, significant from 50 mg/l, which is the drinking-water standard) indicates how much nitrogen the water brings: it feeds algae and contributes to night-time oxygen crashes (Camargo et al. 2005). Nitrites and ammonium above the standard at any station add one point, because nitrites are poisonous to fish (Lewis and Morris 1986); in deep groundwater they can also be natural, so only one point. The adjustment is multiplied by the reliability of the data.

    Sources: SHMÚ, groundwater; Camargo et al. 2005; Lewis and Morris 1986

    −1
  • Harmful substances in groundwater (SHMÚ)Level of evidence: Partly supported

    metals and metalloids (above the standard at 1 of 8 stations), highest value 12 times the standard

    Metals, pesticides, PFAS and chlorinated solvents above the standard show the burden on the surroundings. The standards are set for drinking water and are stricter than the limits harmful to fish, so the reduction is small; metals can also come from rocks. PAHs are not counted in the score. Data reliability is 100% (8 stations within 10 km, the nearest 1 km, data from 2025); the adjustment was applied in full.

    What we know about it

    Metals and metalloids, pesticides, PFAS and chlorinated solvents above the standard at stations within 10 km. The standards are drinking-water standards and stricter than the limits harmful to fish, so the reduction is small: one point for one or two groups of substances, two points for three groups or for a value at least five times above the standard. Metals are poisonous to fish, more so in soft water (Pagenkopf 1983), and PFAS accumulate in tissues (Giesy and Kannan 2001); metals can also come from rocks. PAHs are not counted. The adjustment is multiplied by the reliability of the data.

    Sources: SHMÚ, groundwater; Pagenkopf 1983; Giesy and Kannan 2001

    −2
  • Iron in groundwater (SHMÚ)Level of evidence: Partly supported

    iron typically 2.79 mg/l (standard 0.2)

    Dissolved iron precipitates when groundwater emerges into the air and clogs gills, gravel with eggs and invertebrate shelters. Data reliability is 100% (8 stations within 10 km, the nearest 1 km, data from 2025); the adjustment was applied in full.

    What we know about it

    Dissolved iron precipitates when groundwater emerges into the air and clogs gills, egg-bearing gravel and the shelters of invertebrates (Vuori 1995). It is counted at a typical value of at least 1 mg/l (five times the standard); the adjustment of −1 is multiplied by the reliability of the data.

    Sources: SHMÚ, groundwater; Vuori 1995

    −1

Life by the water−1

  • Aquatic insect hatchesLevel of evidence: Anglers' practice

    0.0× the average month, 0 of 50 observations in the year, iNaturalist

    Aquatic insects are scarce this month; food near the bottom matters more.

    What we know about it

    Anglers fish "by the insects" (dry and wet fly). A measured relationship between catches and insect hatches is not documented in our sources.

    0
  • Invasive species nearbyLevel of evidence: Anglers' practice

    Prussian carp, GBIF

    Invasive species displace native fish and occupy shallows. The score reduction is only small.

    What we know about it

    Invasive species displace native fish. The score reduction is only small.

    −1

Do not change the score

Data for these factors is missing or within the normal range:

  • Dissolved oxygen
  • Nutrients in the water
  • Water acidity (pH)
  • Water acidity from the atlas
  • Ammonium ions in water
  • Water temperature for local species
  • Surface water (SHMÚ)
  • Chlorides in groundwater
  • Wastewater treatment plants
  • Watercourse size
  • Bottom by geology

The rules are indicative and based on fishing practice and scientific studies; for each factor you can see how well it is supported. Weather, air pressure and water temperature affect the score more than this data does.

Water pollution

Water pollution (SHMÚ)Water quality indicators that fail the standards at the nearest monitoring site on the same watercourse in the SHMÚ yearbooks for 2022 to 2025.
Treatment plants within 2 km
1no unmet requirements
Polluted water in Slovakia: the worst places and polluters

The data comes from the SHMÚ yearbooks (surface waters 2022 to 2025). The yearbook lists the sites that failed the standard; a site missing from the yearbook is not considered clean. We determine the distance and the match of the watercourse name ourselves, so the assignment is indicative.

Groundwater nearby

Groundwater nearby (SHMÚ)Measured groundwater values from stations within 10 km of the fishing district (nitrates, harmful substances, ammonium, iron, chlorides) and the SHMÚ yearbooks.

Groundwater within 10 km (8 stations)

  • Moravsky Svaty JanSenica district · borehole or well · 1.0 km from the fishing district
    natural substances only
    2017 to 2025

    Exceeded in 2025:

    • Manganese
    • Total iron
    • TOC
    Measured values, year 2025, sampling 6 Nov 2025 (2 samplings, the highest value of the year for each substance)
    • Nitrates< 1 mg/l
    • Ammonium0.35 mg/l
    • Nitrites0.02 mg/l
    • Iron12.2 mg/l
    • Chlorides38.2 mg/l
    • Arsenic19% of the standard
  • Laksarska Nova Ves – ZelenacekSenica district · spring · 1.1 km from the fishing district
    natural substances only
    2017 to 2025

    Exceeded in 2025:

    • TOC
    Measured values, year 2025, sampling 4 Jun 2025
    • Nitrates20.9 mg/l
    • Ammonium< 0.01 mg/l
    • Nitrites0.28 mg/l
    • Iron0.019 mg/l
    • Chlorides4.2 mg/l
    • Aluminium80% of the standard
  • GajaryMalacky district · borehole or well · 3.3 km from the fishing district
    natural substances only
    2017 to 2025

    Exceeded in 2025:

    • Manganese
    • Total iron
    • Ammonium
    • TOC
    Measured values, year 2025, sampling 6 Nov 2025 (2 samplings, the highest value of the year for each substance)
    • Nitrates< 1 mg/l
    • Ammonium1.18 mg/l
    • Nitrites0.01 mg/l
    • Iron2.79 mg/l
    • Chlorides39.9 mg/l
    • Nickel10% of the standard
Show 5 more
  • GajaryMalacky district · borehole or well · 4.2 km from the fishing district
    substances from human activity
    2017 to 2025

    Exceeded in 2025:

    • Ratio of NO3 to NO2
    • Nitrates
    • TOC
    Measured values, year 2025, sampling 14 Apr 2025
    • Nitrates74.5 mg/l
    • Ammonium< 0.01 mg/l
    • Nitrites0.01 mg/l
    • Iron0.002 mg/l
    • Chlorides61.2 mg/l
    • Nickel15% of the standard
  • Moravsky Svaty Jan – SekuleSenica district · borehole or well · 4.4 km from the fishing district
    natural substances only
    2017 to 2025

    Exceeded in 2025:

    • Manganese
    • Total iron
    • TOC
    Measured values, year 2025, sampling 9 Oct 2025 (2 samplings, the highest value of the year for each substance)
    • Nitrates< 1 mg/l
    • Ammonium0.48 mg/l
    • Nitrites< 0.01 mg/l
    • Iron3.95 mg/l
    • Chlorides43.7 mg/l
    • Aluminium65% of the standard
    • 1,2,4-triazole (azole pesticides)50% of the standard
  • Bilkove HumenceSenica district · borehole or well · 5.2 km from the fishing district
    no exceedance in 2025
    2017 to 2025

    Last exceeded in 2019:

    • Manganese
    • Total iron
    • COD-Mn
    • Aluminium
    Measured values, year 2025, sampling 14 Apr 2025
    • Nitrates< 1 mg/l
    • Ammonium0.03 mg/l
    • Nitrites0.03 mg/l
    • Iron0.003 mg/l
    • Chlorides< 1 mg/l
    • Selenium10% of the standard
  • Malacky-kostolisteMalacky district · borehole or well · 5.5 km from the fishing district
    natural substances only
    2017 to 2025

    Exceeded in 2025:

    • Manganese
    • Total iron
    • Conductivity at 20 °C
    • TOC
    • COD-Mn
    • Chlorides
    • Aluminium
    • Sodium
    Measured values, year 2025, sampling 24 Apr 2025
    • Nitrates< 1 mg/l
    • Ammonium0.2 mg/l
    • Nitrites0.03 mg/l
    • Iron3.67 mg/l
    • Chlorides371 mg/l
    • Aluminium1,195% of the standard
  • Borsky MikulasSenica district · borehole or well · 6.0 km from the fishing district
    natural substances only
    2017 to 2025

    Exceeded in 2025:

    • Manganese
    • Ammonium
    • Conductivity at 20 °C
    • TOC
    • Sulphates
    • COD-Mn
    • Sodium
    Measured values, year 2025, sampling 14 Apr 2025
    • Nitrates< 1 mg/l
    • Ammonium5.94 mg/l
    • Nitrites0.02 mg/l
    • Iron0.059 mg/l
    • Chlorides16.9 mg/l
    • Arsenic19% of the standard
  • substances from human activity
  • natural substances only
  • no exceedance recorded

Groundwater reaches streams as base flow, so the connection to the stream at the fishing district is only indirect. Natural substances (iron, manganese, sulfates, conductivity) are not counted in the yearbook-based assessment.

The data comes from the SHMÚ yearbooks (groundwater 2017 to 2025).

Wastewater treatment plants

Wastewater treatment plants near the fishing districtPlants within 2 km of the district: overload, compliance with EU requirements and discharged load (BOD₅, COD, nitrogen, phosphorus in tonnes per year).
  • COV Moravsky Svaty Jan1.9 km from the fishing district · capacity 4,500 PE · mechanical, biological
    within the standard
    73% of capacity

Treatment plants within 2 km of the fishing district. The treatment plant need not lie upstream of the fishing district; we do not assess the watercourse at the plant. Load is the ratio of the pollution produced to the capacity of the treatment plant (PE = population equivalent).

River basin and reservoir

Reservoir depth (HydroLAKES)Average depth, volume and water retention time in the reservoir from the HydroLAKES database (WWF). The depth is estimated by a model from the surrounding terrain, so it is approximate.

Watercourse from the HydroRIVERS database matched with the fishing district, line deviation about 40 m

Catchment above the spotWatercourse size (HydroRIVERS)The catchment area above the spot, the stream order and the average flow from the HydroRIVERS database (WWF). It determines whether it is a stream, a river or a large river.
37 km²stream
Average flow
0.14 m³/smodel value
Stream order (Strahler)
1upper course, small tributary
Channel gradient
2.7 ‰Gentle gradient

The data come from a global database with a coarser resolution (tens of metres), so they are only approximate for small waters. Depth and volume are model averages.

Bottom and bedrock

Bottom and bedrock (ŠGÚDŠ)The bedrock under the water according to the hydrogeological map of Slovakia at 1 : 50,000 (ŠGÚDŠ). It tells whether the surroundings are gravelly, sandy, clayey, muddy or rocky.

Shallower sections with fewer hiding places; fish stay by the banks and obstacles.

  • Gravels 29%
  • Sands 43%
  • Clays and loams 29%
Springs and outflows
0none within 1 km

According to the geological map: fluviálne sedimenty: jemnozrnné a strednozrnné piesky až piesčité štrky v agradačných valoch, pleistocén – holocén | fluviálne sedimenty: litofaciálne nečlenené nivné hliny, alebo piesčité až štrkovité hliny dolinných ní

The fishing district description states the bottom: fine-grained, muddy; the geological map shows something different, and the district description is more precise.

The map shows the bedrock geology, not the exact bottom at the spot. The actual bottom material may differ, especially where sediment has been deposited.

Aquatic insects

Aquatic insect swarming (iNaturalist)How many observations of mayflies, caddisflies and stoneflies people nearby recorded this month compared with the annual average. For fly anglers it hints at insect hatches.

Few insects November: 0.0× the average month

  • MayfliesMayflies0Mayflies: dry fly on the surface, especially at dusk.
  • CaddisfliesCaddisflies0Caddisflies: in the evening and at night by the bank; a nymph and a wet fly also work.
  • StonefliesStoneflies0Stoneflies: clean, cold streams, often already at the end of winter and in early spring.
Photo credits

0.0× the average month, 0 of 50 observations in the year, iNaturalist.

The observations are added by people from the surrounding area; they are not measurements at the water. They show when aquatic insects usually appear and are useful mainly for fly fishing.

Groundwater: measured values

Groundwater nearby (SHMÚ)Measured groundwater values from stations within 10 km of the fishing district (nitrates, harmful substances, ammonium, iron, chlorides) and the SHMÚ yearbooks.

A typical value from 8 groundwater stations within 10 km of the fishing district (nearest 1 km), measured in 2025. Closer stations carry more weight. This is groundwater near the district, not a measurement in the watercourse itself. The standard is the limit that SHMÚ gives for the indicator (for drinking water); a value equal to the standard counts as an exceedance, as it does at SHMÚ. The label "somewhere above the standard" means that the typical value is below the standard but at least one station exceeds it; which one is shown on the tile. Fish are more sensitive to some substances than people are.

00.75

Ammonium

0.35mg/l

close to the standard

Standard 0.5 mg/l. Range 0.005 to 5.94 mg/l, 8 stations. Above the standard: 2 of 8 (highest: Borsky Mikulas, 6 km from the fishing district).

00.75

Nitrites

0.02mg/l

far below the standard

Standard 0.5 mg/l. Range 0.005 to 0.28 mg/l, 8 stations.

075

Nitrates

0.5mg/l

above the standard somewhere

Standard 50 mg/l. Range 0.5 to 74.5 mg/l, 8 stations. Above the standard: 1 of 8 (Gajary, 4.2 km from the fishing district).

012

Oxygen

0.09mg/l

low oxygen

Mark on the dial: 9 mg/l, the guideline for salmonid waters. Range 0.015 to 5.9 mg/l, 8 stations.

020

Water temperature

11.2°C

warmer

Range 9.3 to 12.6 °C, 8 stations.

510

pH

7.1

suitable for fish

Range 6.89 to 7.48, 8 stations.

08

Water hardness

3.85mmol/l

hard

Range 1.34 to 7.39 mmol/l, 8 stations.

00.3

Iron

2.79mg/l

above the standard

Standard 0.2 mg/l. Range 0.002 to 12.2 mg/l, 8 stations. Above the standard: 4 of 8 (highest: Moravsky Svaty Jan, 1 km from the fishing district).

00.075

Manganese

0.4mg/l

above the standard

Standard 0.05 mg/l. Range 0.006 to 2.49 mg/l, 8 stations. Above the standard: 5 of 8 (highest: Borsky Mikulas, 6 km from the fishing district).

0375

Chlorides

38.2mg/l

above the standard somewhere

Standard 250 mg/l. Range 0.5 to 371 mg/l, 8 stations. Above the standard: 1 of 8 (Malacky-kostoliste, 5.5 km from the fishing district).

0375

Sulphates

93.6mg/l

above the standard somewhere

Standard 250 mg/l. Range 12.5 to 562 mg/l, 8 stations. Above the standard: 1 of 8 (Borsky Mikulas, 6 km from the fishing district).

0188

Conductivity

75.2mS/m

close to the standard

Standard 125 mS/m. Range 28.4 to 212 mS/m, 8 stations. Above the standard: 2 of 8 (highest: Borsky Mikulas, 6 km from the fishing district).

0150%

Metals and metalloids

19% of standard

above the standard somewhere

Highest: Aluminium 2.39 mg/l (1,195% of the standard, 5.5 km from the fishing district). 8 stations. Above the standard: 1 of 8.

0150%

Pesticides

0% of standard

below the standard

Highest: 1,2,4-triazole (azole pesticides) 0.05 µg/l (50% of the standard, 4.4 km from the fishing district). 2 stations.

0150%

PFAS (“forever chemicals”)

0% of standard

not detected

Below the limit of quantification: substances from this group were not detected in the samples. 1 station.

0150%

Solvents and benzene

0% of standard

not detected

Below the limit of quantification: substances from this group were not detected in the samples. 1 station.

0150%

PAHs (combustion, petroleum substances)

0% of standard

not detected

Below the limit of quantification: substances from this group were not detected in the samples. 1 station.

How it affects fish and the water
Ammonium
Ammonium ions are not very toxic in themselves, but depending on pH and temperature part of them turns into ammonia (NH₃), which damages the gills and stresses fish. The higher the pH and temperature, the more ammonia there is (Emerson et al. 1975). The repealed Directive 2006/44/EC gave a guideline of at most 0.04 mg/l of ammonium for salmonid waters and 0.2 mg/l for cyprinid waters.
Nitrites
Nitrites are toxic to fish: they pass through the gills into the blood and turn hemoglobin into methemoglobin, which does not carry oxygen, so fish "suffocate" even in oxygenated water. Salmonids are the most sensitive; chlorides in the water reduce the toxicity (Lewis and Morris 1986). Directive 2006/44/EC gave a guideline of 0.01 mg/l for salmonid waters.
Nitrates
Nitrates do not harm adult fish immediately, but they feed algae and plants and so contribute to over-fertilization and nighttime oxygen crashes. For sensitive aquatic animals (salmonids, amphibians, some invertebrates) Camargo et al. (2005) recommend keeping nitrates below 2 mg of nitrogen per liter, which is about 9 mg/l of nitrates.
Oxygen
Fish, especially salmonids, need a lot of oxygen. Directive 2006/44/EC gave a guideline of 9 mg/l for salmonid waters (in at least half of the measurements) and never less than 7 mg/l. Groundwater from deeper layers often has less of it; in the stream it is re-oxygenated only after it emerges.
Water temperature
Groundwater has an almost constant temperature throughout the year. Inflow from springs can therefore cool a stream in summer and warm it in winter, and such sections often serve as refuges for cold-water fish (Hayashi and Rosenberry 2002).
pH
Fish tolerate a pH of roughly 6 to 9 (Directive 2006/44/EC). Outside this range the gills are damaged and the toxicity of ammonia and metals changes.
Water hardness
Harder water (more calcium and magnesium) is better for fish: calcium protects the gills and reduces the toxicity of metals such as copper and zinc (Pagenkopf 1983), and keeps the pH stable. Soft water is more sensitive to metals and to acidification.
Iron
Iron is dissolved in groundwater at depth. When the water reaches the air, it oxidizes and precipitates as brown flocs that clog gills, cover gravel with eggs and invertebrates, and destroy shelters (Vuori 1995).
Manganese
Manganese is natural in deeper groundwater. For fish it tends to matter less than iron; the standard applies mainly because of the taste and color of drinking water.
Chlorides
Chlorides come from road salt, fertilizers and waste. The US EPA (1988) set 230 mg/l for long-term protection of aquatic life and 860 mg/l for short-term.
Sulphates
Sulfates are common in groundwater; they come from rocks (for example gypsum), fertilizers and mines. Together with chlorides they raise the mineralization of the water; the standard of 250 mg/l is set for drinking water.
Conductivity
Conductivity shows the total amount of dissolved salts. A higher value in groundwater is often natural (limestone, gypsum), but a sharp increase in a stream points to an inflow of salts from roads, mines or waste.
Metals and metalloids
Copper, zinc, nickel, cadmium and mercury are toxic to fish even at low concentrations, more so in soft water than in hard water (Pagenkopf 1983). The groundwater standard is set for drinking water, not for fish.
Pesticides
Pesticides get into groundwater from fields. The standard of 0.1 µg/l per substance (0.5 µg/l in total) is a drinking-water standard and is very strict; fish are usually harmed only by a much higher concentration. The value mainly shows how heavily the surroundings are burdened by agriculture.
PFAS (“forever chemicals”)
PFAS are “forever chemicals”: they do not break down and accumulate in the tissues of fish and other animals (Giesy and Kannan 2001). The standard of 0.1 µg/l (sum of 20 substances) is set for drinking water.
Solvents and benzene
Chlorinated solvents (for example tetrachloroethene) and benzene come from industry, treatment plants and petrol stations. They are toxic and break down slowly in groundwater.
PAHs (combustion, petroleum substances)
PAHs are formed by combustion and petroleum spills. The standard for benzo(a)pyrene (0.01 µg/l) is very strict for drinking water because it is a carcinogen.

Sources

  1. Camargo, J. A., Alonso, Á., Salamanca, A. (2005): Nitrate toxicity to aquatic animals: a review with new data for freshwater invertebrates. Chemosphere 58, 1255–1267.
  2. Lewis, W. M., Morris, D. P. (1986): Toxicity of nitrite to fish: a review. Transactions of the American Fisheries Society 115, 183–195.
  3. Emerson, K., Russo, R. C., Lund, R. E., Thurston, R. V. (1975): Aqueous ammonia equilibrium calculations: effect of pH and temperature. Journal of the Fisheries Research Board of Canada 32, 2379–2383.
  4. Directive 2006/44/EC on the quality of fresh waters needing protection or improvement in order to support fish life (repealed in 2013; we give its values here only as an expert guideline).
  5. Vuori, K.-M. (1995): Direct and indirect effects of iron on river ecosystems. Annales Zoologici Fennici 32, 317–329.
  6. Pagenkopf, G. K. (1983): Gill surface interaction model for trace-metal toxicity to fishes: role of complexation, pH, and water hardness. Environmental Science & Technology 17, 342–347.
  7. U.S. EPA (1988): Ambient Water Quality Criteria for Chloride. EPA 440/5-88-001.
  8. Hayashi, M., Rosenberry, D. O. (2002): Effects of ground water exchange on the hydrology and ecology of surface water. Ground Water 40, 309–316.
  9. Giesy, J. P., Kannan, K. (2001): Global distribution of perfluorooctane sulfonate in wildlife. Environmental Science & Technology 35, 1339–1342.

Fish, wildlife, plants and hazards around the waterFish nearby (GBIF)Fish species that people have recorded around the water (GBIF database, recent decades). It is not a list of species in the fishing district, only a hint of what occurs in the area.Wildlife and hazards by the water (GBIF)Game animals, birds, plants and hazards (bear, ticks, mosquitoes, giant hogweed) that people have recorded around the water. It is not part of the fishing conditions score and is for information only.

Species that have been observed or recorded near the water. The number next to a fish is the number of records in the GBIF database, not the number of fish. Wildlife, plants and hazards do not enter the fishing conditions score; they are for information only. The species name leads to its page.

SpirlinFish

Spirlin

Alburnoides bipunctatus

prefers 12–16 °C, up to 19 cm and 0.0 kg, requires a lot of oxygen

TenchFish

Tench

Tinca tinca
game species

prefers 18–26 °C, spawns at 19–24 °C, up to 70 cm and 7.5 kg, tolerates low oxygen

Prussian carpInvasive species

Prussian carp

Carassius gibelio
game species

prefers 14–28 °C, spawns at 14–20 °C, up to 45 cm and 3.0 kg, tolerates low oxygen

MallardBird

Mallard

many records
Most records: April.
About the species

The most common duck; it nests by almost every water with bankside vegetation.

Grey heronBird

Grey heron

protected speciesmany records
Most records: April.
About the species

It stands in the shallows and lies in wait for small fish. It is easy to see along the banks of ponds and slow streams.

Mute swanBird

Mute swan

protected speciesmany records
Most records: April.
About the species

A large white waterbird that nests by slow waters, reservoirs and ponds with vegetation.

Black-headed gullBird

Black-headed gull

protected speciesmany records
Most records: May.
About the species

The most common gull by the water. Nests in colonies at ponds and large reservoirs and also stays along rivers.

DragonfliesWildlife

Dragonflies

quite a few records
Most records: July.
About the species

Predatory insect. The larvae live underwater for several months to years; adult dragonflies hunt in the air above the water.

CaddisfliesWildlife

Caddisflies

quite a few records
Most records: May.
About the species

Insects whose larvae, in many species, build protective cases from pebbles, sand or plants.

Grass snakeWildlife

Grass snake

protected speciesquite a few records
Most records: May.
About the species

A harmless snake with two yellow spots on the nape. It swims well and hunts frogs, fish and newts.

Common toadWildlife

Common toad

protected speciesa few records
Most records: April.
About the species

The largest native toad. In spring it migrates to water, where it breeds.

Eurasian beaverWildlife

Eurasian beaver

protected speciesa few records
Most records: October.
About the species

A herbivore that changes the stream and its banks with dams and burrows. It is protected. It creates shallows and pools where fish and insects thrive.

Green frogs (water frogs)Wildlife

Green frogs (water frogs)

protected speciesa few records
Most records: August.
About the species

A group of green frogs that sit by the bank and jump into the water when disturbed.

European pond turtleWildlife

European pond turtle

protected speciesa few records
Most records: May.
About the species

The only native turtle in Slovakia. It lives in standing and slow waters with a soft bottom.

MuskratWildlife

Muskrat

invasive speciesa single record
Most records: March.
About the species

A rodent from North America that swims well and feeds on bankside plants. It digs burrows into the banks.

Black alderPlant

Black alder

many records
Most records: June.
About the species

A riparian tree whose roots reach below the water surface.

Common reedPlant

Common reed

many records
Most records: June.
About the species

Tall grass that forms extensive reed beds around ponds and on banks.

Yellow flag irisPlant

Yellow flag iris

many records
Most records: May.
About the species

A tall wetland plant with yellow flowers that grows on damp banks.

Common duckweedPlant

Common duckweed

quite a few records
Most records: September.
About the species

A tiny floating plant that can cover the whole surface of standing water.

Himalayan balsamInvasive plant

Himalayan balsam

invasive speciesquite a few records
Most records: September.
About the species

An invasive plant from the Himalayas, up to two metres tall, with pink flowers. It overgrows the banks of watercourses.

Japanese knotweedInvasive plant

Japanese knotweed

invasive speciesquite a few records
Most records: October.
About the species

An invasive herb from East Asia that forms dense stands up to three metres tall.

Castor bean tickRisk

Castor bean tick

to be reckoned witha few records
Most records: April.
How to protect yourself

Transmits tick-borne encephalitis and Lyme disease. It waits in tall grass and in the vegetation along banks.

How to protect yourself: From spring to autumn check yourself after fishing, use repellent and tuck long trousers into your socks. Remove a tick as soon as possible with tweezers. A vaccination against encephalitis exists.

Giant hogweedRisk

Giant hogweed

to be reckoned withinvasive speciesa few records
Most records: June.
How to protect yourself

An invasive plant that grows along stream banks and on wet meadows. In sunlight its sap causes skin burns.

How to protect yourself: Do not touch it and do not walk through the vegetation. If the sap gets on your skin, wash it off with water and soap and protect the area from the sun. See a doctor for larger burns.

HorsefliesRisk

Horseflies

to be reckoned witha few records
Most records: July.
How to protect yourself

Large biting flies. They are most active on hot, windless days near water and on meadows.

How to protect yourself: They sting painfully, especially in summer around midday. Light-colored clothing with long sleeves and repellent help.

Wild boarRisk

Wild boar

to be reckoned witha few records
Most records: April.
How to protect yourself

It comes to the water to wallow and drink, mainly at dusk and at night.

How to protect yourself: A wild boar sow with piglets can be aggressive. Keep your distance, do not spend the night on a game trail and do not leave food scraps near the water.

MosquitoesRisk

Mosquitoes

to be reckoned witha single record
Most records: April.
How to protect yourself

They breed in standing water, so they are worst around reservoirs, oxbow lakes and floodplain forests, especially at sunset.

How to protect yourself: When fishing in the evening and at night wear long sleeves, repellent and a net. Warmth and humidity after rain speed up mosquito development.

Fish: records since 1995 from the surroundings of the water (a rectangle around the fishing district). These are observations and collections, not a list of the fish in the fishing district, so a species may be missing even where it lives.

Invasive species (red label) displace native fish and occupy shallows. Catching and handling them is governed by the fishing regulations; check them before fishing.

Wildlife, plants and hazards: records come from observations and also reflect where observers move around; they are not density measurements or a guarantee of an encounter. They apply to the surroundings of about 35 × 55 km.

Photo credits

Fish catalogue with all species Animal and plant catalog

Ground under the water: geology, faults and radon

Bedrock, watercourse and springs on the map, values at the location of the water, geomagnetic activity and earthquakes. This is information about the environment; only small hypotheses marked with a confidence level (faults and rocks, geomagnetic storm) enter the score.

The bedrock map needs JavaScript to be turned on.

The map can be panned and zoomed; the ŠGÚDŠ layers are stored on this server. © State Geological Institute of Dionýz Štúr. Base map scale 1 : 50,000 (faults and geology); radioactivity and magnetics are coarser.

Values at the water spot

Values at the water spotBedrock radon risk, uranium, thorium, potassium, gamma radiation and magnetic anomaly at a single spot by the water (marked with a dot on the map).

Radon risk of the bedrock

low

Bedrock with a low radon share.

08

Uranium (eU)

2.3ppm

common

Typical background of the rocks.

020

Thorium (eTh)

4.6ppm

below the crustal average

Natural background of the rocks.

04

Potassium (K)

1.23%

below the crustal average

Natural background of the rocks.

0150

Gamma radiation

41nGy/h

below the world average

Natural background of the bedrock.

SVJZ

Magnetic anomaly (ΔT)

52nT

above the average of the surroundings

Deviation of the magnetic field from the average of the surroundings.

The values apply to a single spot (marked with a dot on the map), not as an average of the whole watercourse or river basin. Radon is a natural tracer in groundwater; the map does not include radon in water, only the bedrock risk.

Mark on the dial: the average of the upper continental crust (uranium 2.7 ppm, thorium 10.5 ppm, potassium 2.3%; Rudnick and Gao 2003) and the world average of the natural outdoor dose 59 nGy/h (UNSCEAR 2000). The needle does not swing towards “good” or “bad”; it only shows where the value lies.

Elevated uranium or radon is only information about the rock. It has no proven significance for bites; it helps to read what bedrock the water comes from.

Faults and springs

Faults and springsThe distance to the nearest tectonic fault on the geological map and the number of springs nearby. Fissure groundwater flows out along faults.
250 m1 km3 km8 km

Nearest fault

up to 3 km

fault nearby

Tectonic fault on the geological map.

Springs and outflows

0

none marked

None within 1 km.

covered by younger sediments

Fissure groundwater flows out of the bedrock along faults and at springs. It tends to be cooler in summer and warmer in winter than the water in the stream, so according to anglers' experience fish stay near such places in extreme weather (summer and winter islands of a more suitable temperature).

However, fresh fissure water can have little oxygen. This is anglers' experience, not a phenomenon measured at this fishing district.

Faults are from the geological map at 1 : 50,000. Springs come from a hydrogeological map that covers only some regions, so zero does not mean there are no springs there.

Geology nearby: rock, water, sediments, boreholes

Geology and geochemistry around the waterRock under the water, composition of water and sediments according to the atlases, radioactivity, geothermal potential, boreholes, old mine workings, deposits, burdens, landslides and gold in sediments, from ŠGÚDŠ maps and registers.
MA (013) / Malé Leváre – bývalé JRD – livestock production – poľnohospodárska výro (340 m from the water)MA (014) / Malé Leváre – bývalé pieskovne – sklá – landfill komunálneho odpadu – zariadenia (370 m from the water)MA (030) / Závod – stará štrkovňa – skládka s OP – landfill komunálneho odpadu – zariadenia (1.8 km from the water)MA (027) / Veľké Leváre – stará štrkovňa u Hozu – landfill komunálneho odpadu – zariadenia (1.8 km from the water)MA (001) / Gajary – Levárska cesta – skládka s O – landfill komunálneho odpadu – zariadenia (2.9 km from the water)MA (026) / Veľké Leváre – bývalé JRD – livestock production – poľnohospodárska výro (3.0 km from the water)Lakšárska Nová Ves – permanent (90 m from the water)Lakšárska Nová Ves – occasional (110 m from the water)Závod – occasional (160 m from the water)Malé Leváre – permanent (360 m from the water)Malé Leváre – permanent (540 m from the water)Hrabovec – Lakšárska Nová Ves – occasional (570 m from the water)Tomky – Borský Svätý Jur – occasional (740 m from the water)Moravský Svätý Ján – none (790 m from the water)Závod – permanent (820 m from the water)Hrabovec – Lakšárska Nová Ves – occasional (850 m from the water)Husáriska – Moravský Svätý Ján – occasional (950 m from the water)Malé Leváre – occasional (960 m from the water)Lakšárska Nová Ves – occasional (1.0 km from the water)Lakšárska Nová Ves – – (1.0 km from the water)Hrabovec – Lakšárska Nová Ves – occasional (1.0 km from the water)Pri Husár.rybníkoch – Lakšárska Nová Ves – occasional (1.1 km from the water)Malé Leváre – cannot be estimated (1.3 km from the water)Malé Leváre – permanent (1.3 km from the water)Lakšárska Nová Ves – occasional (1.3 km from the water)Lakšárska Nová Ves – occasional (1.4 km from the water)Lakšárska Nová Ves – occasional (1.4 km from the water)Lakšárska Nová Ves – occasional (1.4 km from the water)Lakšárska Nová Ves – occasional (1.4 km from the water)Lakšárska Nová Ves – occasional (1.4 km from the water)centrálne kalisko – Moravský Svätý Ján – cannot be estimated (1.4 km from the water)Lakšárska Nová Ves – occasional (1.4 km from the water)Závod – occasional (1.5 km from the water)Lakšárska Nová Ves – occasional (1.5 km from the water)Lakšárska Nová Ves – occasional (1.5 km from the water)Lakšárska Nová Ves – occasional (1.6 km from the water)Lakšárska Nová Ves – occasional (1.6 km from the water)Závod – none (1.6 km from the water)Lakšárska Nová Ves – – (1.7 km from the water)Závod – occasional (1.7 km from the water)Závod – occasional (1.7 km from the water)Lakšárska Nová Ves – occasional (1.7 km from the water)Závod – occasional (1.8 km from the water)Veľké Leváre – occasional (1.8 km from the water)Závod – permanent (2.0 km from the water)Závod – occasional (2.0 km from the water)Závod – occasional (2.0 km from the water)Moravský Ján – Moravský Svätý Ján – occasional (2.2 km from the water)Závod – occasional (2.3 km from the water)Závod – none (2.4 km from the water)Závod – occasional (2.5 km from the water)Závod – permanent (2.7 km from the water)Gajary – bývalá obecná skládka – Gajary – – (2.9 km from the water)Lakšárska Nová Ves – RGL-1 – non-spa (2.8 km from the water)Šaštín-Stráže – RGL-2 – non-spa (7.9 km from the water)RGL-1 – l3 (3.7 km from the water)RGL-2 – l2 (8.0 km from the water)a1 (1.5 km from the water)a1 (3.6 km from the water)a1 (5.3 km from the water)a1 (6.3 km from the water)a1 (6.7 km from the water)b1 (7.7 km from the water)Malé Leváre – gravelly sands and sands (270 m from the water)Závod – combustible natural gas (1.1 km from the water)Studienka – combustible natural gas (1.1 km from the water)Závod – semi-paraffinic crude oil (1.1 km from the water)Studienka – semi-paraffinic crude oil (1.1 km from the water)Závod – mezozoikum – gasoline (3.0 km from the water)Závod – mezozoikum – combustible natural gas (3.0 km from the water)Závod – juh (báden) – combustible natural gas (3.0 km from the water)Borský Jur – západná časť – brick raw materials (4.2 km from the water)Borský Jur – brick raw materials (4.3 km from the water)Šaštín – glass sands (4.7 km from the water)Šaštín – foundry sands (4.7 km from the water)Borský Jur – východná časť – brick raw materials (4.8 km from the water)Gajary – báden – gasoline (5.0 km from the water)PZZP Láb (Gajary – báden) – underground natural gas storage facilities (5.0 km from the water)PZZP Láb – 3. stavba – underground natural gas storage facilities (5.0 km from the water)Gajary – báden – combustible natural gas (5.0 km from the water)Gajary – báden – semi-paraffinic crude oil (5.0 km from the water)Suchohrad – Gajary – combustible natural gas (5.0 km from the water)Malé Leváre – gravelly sands and sands (270 m from the water)Závod – semi-paraffinic crude oil (1.1 km from the water)Studienka – semi-paraffinic crude oil (1.1 km from the water)Studienka – combustible natural gas (1.1 km from the water)Závod – combustible natural gas (1.1 km from the water)Lakšárska Nová Ves I – foundry sands (1.4 km from the water)Lakšárska Nová Ves – lignite (2.1 km from the water)Závod – mezozoikum – gasoline (3.0 km from the water)Závod – mezozoikum – combustible natural gas (3.0 km from the water)Závod – juh (báden) – combustible natural gas (3.0 km from the water)Borský Jur – combustible natural gas (4.1 km from the water)Borský Jur – gasoline (4.1 km from the water)Borský Jur – západná časť – brick raw materials (4.2 km from the water)Borský Jur – brick raw materials (4.3 km from the water)Šaštín – foundry sands (4.5 km from the water)Šaštín – glass sands (4.5 km from the water)Borský Jur – východná časť – brick raw materials (4.8 km from the water)Gajary – báden – gasoline (5.0 km from the water)Gajary – báden – semi-paraffinic crude oil (5.0 km from the water)Gajary – báden – combustible natural gas (5.0 km from the water)Suchohrad – Gajary – combustible natural gas (5.0 km from the water)Lakšárska Nová Ves I – foundry sands (1.4 km from the water)Šaštín – foundry sands (4.5 km from the water)Šaštín – glass sands (4.5 km from the water)Moravský Svätý Ján – Gergelík – gravelly sands and sands (2.0 km from the water)Moravský Svätý Ján – Gergelík I – gravelly sands and sands (2.0 km from the water)Studienka 100 – crude oil, natural gas (80 m from the water)Húšky 1 – natural gas (550 m from the water)Studienka – Závod – crude oil, natural gas (630 m from the water)Studienka 101 – crude oil, natural gas (710 m from the water)Moravský Svätý Ján – gravelly sands (780 m from the water)Studienka – Závod – crude oil, natural gas (1.0 km from the water)Veľké Leváre 17 – crude oil, natural gas (2.0 km from the water)Lakšárska Nová Ves 7 – crude oil, natural gas (2.1 km from the water)Veľké Leváre 10 – crude oil, natural gas (2.5 km from the water)Závod 73 – crude oil, natural gas (3.0 km from the water)Veľké Leváre 14 – crude oil, natural gas (3.1 km from the water)Studienka 111 – natural gas (3.4 km from the water)Borský Jur – crude oil, natural gas (3.5 km from the water)Gajary 125 – crude oil, natural gas (4.9 km from the water)Kostolište – peat (5.0 km from the water)Ciglad – SHMÚ observation borehole (20 m from the water)Malé Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (20 m from the water)Lakšárska Nová Ves – SHMÚ observation borehole (210 m from the water)Závod-Hušek – úzkoprofilový vrt s obyčajnou pitnou a ú (220 m from the water)Moravský Svätý Ján – úzkoprofilový vrt s obyčajnou pitnou a ú (240 m from the water)Lakšárska Nová Ves – úzkoprofilový vrt s obyčajnou pitnou a ú (260 m from the water)Malé Leváre – širokoprofilový vrt (Ø vŕtania nad 600 m (280 m from the water)Studienka-Tomky – úzkoprofilový vrt s obyčajnou pitnou a ú (340 m from the water)Veľké Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (390 m from the water)Malé Leváre – širokoprofilový vrt (Ø vŕtania nad 600 m (590 m from the water)Malé Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (600 m from the water)Tomky – úzkoprofilový vrt s obyčajnou pitnou a ú (610 m from the water)Tomky – SHMÚ observation borehole (620 m from the water)Lakšárska Nová Ves – úzkoprofilový vrt s obyčajnou pitnou a ú (680 m from the water)Dlhé Lúky – úzkoprofilový vrt s obyčajnou pitnou a ú (740 m from the water)Veľké Leváre – širokoprofilový vrt (Ø vŕtania nad 600 m (960 m from the water)Malé Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (970 m from the water)Moravský Svätý Ján – úzkoprofilový vrt s obyčajnou pitnou a ú (970 m from the water)JRD Lakšárska Nová Ves – úzkoprofilový vrt s obyčajnou pitnou a ú (980 m from the water)Studienka-Senica – úzkoprofilový vrt s obyčajnou pitnou a ú (990 m from the water)Lakšárska Nová Ves – úzkoprofilový vrt s obyčajnou pitnou a ú (1.0 km from the water)Lakšárska Nová Ves – širokoprofilový vrt (Ø vŕtania nad 600 m (1.1 km from the water)Lakšárska Nová Ves – širokoprofilový vrt (Ø vŕtania nad 600 m (1.1 km from the water)Lakšárska Nová Ves – úzkoprofilový vrt s obyčajnou pitnou a ú (1.2 km from the water)Lakšárska Nová Ves – úzkoprofilový vrt s obyčajnou pitnou a ú (1.2 km from the water)Malé Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (1.2 km from the water)Lakšárska Nová Ves – úzkoprofilový vrt s obyčajnou pitnou a ú (1.2 km from the water)Závod – monitoring borehole (1.4 km from the water)Malé Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (1.4 km from the water)Malé Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (1.5 km from the water)Studienka – úzkoprofilový vrt s obyčajnou pitnou a ú (1.5 km from the water)Moravský Svätý Ján – úzkoprofilový vrt s obyčajnou pitnou a ú (1.5 km from the water)Malé Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (1.5 km from the water)Závod – úzkoprofilový vrt s obyčajnou pitnou a ú (1.7 km from the water)Malé Leváre – SHMÚ observation borehole (1.7 km from the water)Malé Leváre – úzkoprofilový vrt s obyčajnou pitnou a ú (1.8 km from the water)Závod – úzkoprofilový vrt s obyčajnou pitnou a ú (1.9 km from the water)Moravský Svätý Ján – úzkoprofilový vrt s obyčajnou pitnou a ú (1.9 km from the water)Moravský Svätý Ján – úzkoprofilový vrt s obyčajnou pitnou a ú (2.0 km from the water)Závod – úzkoprofilový vrt s obyčajnou pitnou a ú (2.2 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (220 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (260 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (280 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (280 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (340 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (590 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (590 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (600 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (600 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (630 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (960 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (970 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (980 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (990 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.2 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.2 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.4 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.4 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.5 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.5 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.5 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.7 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.8 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.9 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.9 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.0 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.2 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.3 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.3 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.4 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.5 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.7 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.7 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.7 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.8 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.8 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.8 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.8 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (2.9 km from the water)Lakšárska Nová Ves, č.d. 148, 1400m JZ od K220 – well (20 m from the water)Sisulaky, chaty, 1100m S od K198 – borehole (60 m from the water)Horné Valy, 900m JJZ od K 202 – source (60 m from the water)Horné Valy, 800m JJV od K202 – well (100 m from the water)Sisulaky, chaty, 1000m S od K198 – borehole (110 m from the water)Dolné Valy, 1000m SZ od K177 – source (130 m from the water)Lakšárska Nová Ves – drainage (270 m from the water)Malé Leváre, 1400m VSV od K148 – drainage (310 m from the water)Malé Leváre, 1700m S od K151 – borehole (550 m from the water)Lakšárska Nová Ves, č.d. 229, 2000m J od K220 – well (610 m from the water)Lakšárska Nová Ves-pohostinstvo, 1800m JZ od K25 – borehole (820 m from the water)Studienka, Hrabovec, 1000m JZ od K198 – borehole (970 m from the water)Geciky, plynárne, 200m JV od K200 – well (980 m from the water)Lakšárska Nová Ves, 150m Z od K243 – borehole (1.0 km from the water)Lakšárska Nová Ves, 1800m JV od K229 – source (1.1 km from the water)Lakšárska Nová Ves, č.d. 308, 1600m ZSZ od K243 – well (1.1 km from the water)Malé Leváre, 1000m S od K151 – borehole (1.1 km from the water)Geciky, 800m JJZ od K200 – well (1.6 km from the water)Malé Leváre, 1400m J od K159 – well (1.9 km from the water)Lakšárska Nová Ves, horáreň Biely Kríž – well (2.5 km from the water)Veľké Leváre, 500m SV od K154 – well (2.8 km from the water)Mikulášov, č.d. 1, 500m SV od K243 – borehole (2.8 km from the water)Lakšárska Nová Ves, časť Mikulášovo – drainage (2.8 km from the water)Veľké Leváre, Zámočnícka 165, 1900m SZ od K155 – well (2.9 km from the water)Gajary – RD, 900m ZJZ od K153 – borehole (2.9 km from the water)10 km

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.

Rock under the water

River alluvium88% of the water line

13% young sediments

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

510

Water according to the atlas

pH 7.7modelled estimate

water type Ca–HCO₃–SO₄

Mineralisation 480 mg/l, hard water (14.7 °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: Selenium 0.255 mg/kg

Position of the highest-ranked element among the sample points on streams in Slovakia: percentile 52. Interpolation of the Geochemical Atlas of river sediments.

1 km2 km46 °C76 °C

Heat underfoot

46°C at 1,000 m depth

heat flow 51 mW/m²

At a depth of 2,000 m about 76 °C (increase of 30 °C per kilometre). Atlas of Geothermal Energy of Slovakia.

Gold in river sediment

0samples with gold

9 ore minerals in the sediment

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

3 from 9indicators in the top 5 %

highest: Barium 142 μg/l

Position of the highest measured value in the distribution of all surface water samples in Slovakia: percentile 95 (Lakšársky, potok).

Boreholes and groundwater analyses

776boreholes within 3 km

655 water analyses nearby

Of these, 359 have an archive report from Geofond. The boreholes are hydrogeological, geological, engineering-geological and other.

0 °C120

Geothermal energy

78°C at the wellhead

2 geothermal boreholes within 10 km

Warmest: Lakšárska Nová Ves – RGL-1, yield 25.0 l/s, 2.8 km from the water.

Environmental burdens and landfills

53sites within 3 km

6 environmental burdens, 47 landfills

Nearest burden: MA (013) / Malé Leváre – bývalé JRD, 340 m from the water. Proximity does not mean that substances leak from the site into the water.

Deposits and ore occurrences

60records within 5 km

45 deposits, 15 ore occurrences

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

The data come from registers, maps and atlases of the State Geological Institute of Dionýz Štúr and describe the environment around the water. Proximity of a mine working or burden does not mean the water is polluted. The chemistry of water and sediments is a modelled estimate from interpolated maps of the Geochemical Atlas of Slovakia, not current monitoring or a measurement in the stream.

Detailed geology and geochemistry of the whole stream: rock under the water, water composition, elements in sediments, radiation, geothermal potential, metals, gold in sediment, mine workings, boreholes with analyses.

Geomagnetic activity

Geomagnetic activity (Kp)The planetary Kp index (0 to 9) measures the fluctuation of the Earth's magnetic field. From 5 it counts as a geomagnetic storm. The last 48 hours and a forecast for 24 hours are shown.
09

Kp index

2.7from 9

quiet field

Latest measurement (9 Nov 2026 10:00). The dot on the dial is the highest forecast for the next 24 hours.

Highest forecast Kp in the next 24 hours: 4.7 (unsettled field).

Kp (0 to 9) measures the fluctuation of the Earth's magnetic field caused by the solar wind. From 5 it counts as a geomagnetic storm. Fish, especially salmonids and eels, sense the magnetic field. That their bites depend on Kp has not been shown, though: these are anglers' observations and hypotheses.

The value is the same for the whole of Slovakia. It enters the activity score only during a strong geomagnetic storm (a hypothesis, −1 to −2 points).

Earthquakes nearby

Earthquakes nearbyTremors recorded within 150 km of the water in the last 30 days (GFZ GEOFON catalog).
S

Earthquakes nearby

0tremors

no tremors

Within 150 km over the last 30 days (from magnitude 0.0).

According to angling lore, fish (especially catfish and eels) react restlessly to tremors beforehand or stop biting. This is not reliably proven, and with weak tremors it is coincidence. People mostly do not notice deeper tremors from the Carpathians (for example near Komárno and Dobrá Voda) at all.

The GEOFON catalog is global; weak tremors near Slovakia may not all be in it. It is not counted in the activity score.

Data: © ŠGÚDŠ (geological, geophysical and hydrogeological maps), NOAA SWPC (Kp index), GFZ GEOFON (earthquakes). A link between the geomagnetic field, tremors or radon and fish bites has not been reliably proven, so they are not counted in the activity score. The method is described in Methodology.

From space: what the Copernicus satellites show

Sentinel-2 (optical) and Sentinel-1 (radar), updated roughly every 6 days

  • OvergrowthClean surface
  • IceNo ice

The watercourse is narrower than a satellite pixel (10 m). The values are therefore taken from a strip around the fishing district line and from pixels where water mixes with the bank, so they are only approximate and may also show the bank. The water surface area is not assessed for a watercourse, and estimates over the water appear in the image only where the watercourse is wider than a satellite pixel.

The last usable image is 314 days old (30 Dec 2025) because the fishing district was cloud-covered.

Sentinel-2 satellite image of the surroundings of watercourse Lakšár from 30 Dec 2025, Water (NDWI)
Sentinel-2. Contains modified Copernicus Sentinel data 2025.

Surface overgrowth

Surface overgrowthThe share of the fishing district's area where the satellite sees green vegetation (NDVI index above 0.3): floating and emergent plants and reeds at the bank.
0 % of areaClean surface

The share of the area with green vegetation (plants on and just below the surface, reeds at the bank).

A strip of reeds at the banks may also be counted, so values on small areas may appear higher.

Sentinel-2, 30 Dec 2025, 100% of the area cloud-free

Ice on the surface

Ice on the surfaceThe share of the area where the satellite sees ice or snow. It cannot determine the thickness or load-bearing capacity of the ice.
5 % of areaNo ice

The share of the area where the satellite sees ice or snow. Over the last 20 days the highest was 0%.

The satellite cannot determine the thickness or load-bearing capacity of the ice. Never go onto the ice based on this figure.

Sentinel-2, 30 Dec 2025, 100% of the area cloud-free

Data have been stored since 30 Dec 2025 (55 periods of 5 days); the charts show how they develop. Download history (CSV)

Estimates from satellite images with a resolution of 10 to 20 m, not a measurement in the water. They are affected by clouds, shadows, wind and banks. Do not use them to decide about swimming or going onto the ice. Data: Contains modified Copernicus Sentinel data 2026, ESA, Copernicus Data Space Ecosystem. The procedure is described in the Methodology.

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 fishing district Lakšár from 2017
2017imaged 24 Aug 2017
Aerial image of fishing district Lakšár from 2020
2020imaged 22 Aug 2020
Aerial image of fishing district Lakšár from 2023
2023imaged 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.