Fishing district

Hornád č. 2a

Salmonid (trout)No. 4-0640-4-1HornádBodrog basin and Hornád
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Fishing district boundaries: Čiastkové povodie rieky Hornád od mostu pre peších nad obcou Sokoľ "Sokoľskou lávkou" po cestný most v obci Veľká Lodina.

fishing district length
7.3km
region
Košice Region
Aerial image of fishing district Hornád č. 2a 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

Water level

Water levelThe water level at the nearest SHMÚ gauge in centimetres above the gauge zero. It is the water level at the station, not the depth of the water at the fishing district.
04080120160200

Spišská Nová Ves – Hornád · level stable, gauge 45 km away

The level is measured at an SHMÚ gauge; it is not the depth of the water in the fishing district.

Source: SHMÚUpdated 9 Nov 2026 18:30

Modelled flow

Modeled flowAn estimate of the amount of water in the river (m³/s) from the GloFAS model, not a measurement. The resolution is about 5 km, so on small streams it may show a larger river nearby.

Loading data…

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.

2452502552602652700 km2 km4 km6 km
Elevation profile of the fishing district downstream: from 265 to 250 m a.s.l. over 7.3 km.
Downstream, from the upper end of the fishing district (left) to the lower end
Highest point
265 m a.s.l.
Lowest point
249 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.
16 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.
2.2 ‰
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.
1.44
Source: Open Topo Data (eudem25m)Updated 4 Nov 2026 11:28

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

  • Dawn06:01
  • Sunrise06:34
  • Sunset16:03
  • Dusk16:37

The day lasts 9 h 28 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
  • Moonrise06:58
  • Moonset15:32

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.

  • Golden hour (morning)06:04–07:34
  • Minor solunar period06:28–07:28
  • Main solunar period10:19–12:19
  • Minor solunar period15:02–16:02
  • Golden hour (evening)15:03–16:33
  • Main solunar period22:43–00:43

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

48.85885, 21.19721 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

Manager
SVP, š.p. OZ Košice
Fishing district user
SRZ
Organization
MsO SRZ Košice (Municipal SRZ organization)
Area
Eastern Slovakia
Purpose
Fishing district
Minimal stocking
Pp2 500 kg

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. 0.5–2.5 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. gravelly-stony
  • 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
  • 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: Gravel bottom

    Well-oxygenated water and plentiful food (aquatic insect larvae). Typical of the grayling and barbel zones; gravel bars also serve many fish as spawning grounds.

  • Bottom: Stony bottom

    Typical of fast mountain and foothill streams. There are shelters for trout and other fish among the stones, but your rig often gets snagged.

  • 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.

  • 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.

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

Section 13, paragraph 1 of the Act

1 Oct – 15 Apr

fishing for all fish prohibitedoutside this period

Exception: on waters where huchen occurs, from 1 Nov to 31 Dec fishing for huchen is possible only with a huchen fishing permit (§ 13, para. 4 and § 19 of the Act).

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).

April, September6.00 – 20.00 h

May, August5.00 – 21.00 h

June, July4.00 – 22.00 h

November, December7.00 – 19.00 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

§ 16 of the Act
Number of rods
1
Permitted methods
fly fishing, spinning
Hooks and baits
fly fishing at most 3 artificial flies, spinning one lure
Live or dead baitfish
prohibited
Fishing days of the week
at most 3
Ice fishing
prohibited
Other
prohibition of groundbaiting and of several baits (pastes, granules, pellets, cheese, worms, insects, roe)

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.

Show as a list

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. 4-0640-4-1); 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.
60from 100
Water of below-average suitability for trout

The water is in the bottom 2% of 461 trout fishing districts with data.

  • Best fit: water acidity (pH)
  • Most missing: stream zone

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 2.2 ‰, 257 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 not a natural zone for trout; the fish are here more thanks to stocking and local conditions.

    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

    34
  • Water hardnessLevel of evidence: Hypothesis

    ≈ 13.7 °dH (2.5 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

    93
  • Water acidity (pH)Level of evidence: Partly supported

    pH 8.3, 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

    98
  • MineralizationLevel of evidence: Hypothesis

    ≈ 393 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

    95
  • Metals in sedimentLevel of evidence: Partly supported

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

    Metals in sediment can accumulate in benthic animals and fish; high values are often natural in ore areas.

    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

    35

How this water would suit each type

  • Trout60
  • Grayling73
  • Carp76

The same water data evaluated against the requirements of trout, grayling and carp. The fishing district is registered as a trout 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+1
Public data about this water hardly change the activity score.
  • Biggest boost: Watercourse size +1
  • Biggest deduction: Bottom by geology −1

We assessed 18 factors; 4 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

    ≈ 13.7 °dH, ŠGÚDŠ atlas

    A harder, calcium-rich basin gives more productive water, in which trout and grayling grow 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

Watercourse, reservoir and bottom0

  • Watercourse sizeLevel of evidence: Anglers' practice

    catchment above the spot 1,956 km², average flow 17.4 m³/s, HydroRIVERS

    A large river has a more stable temperature and water level.

    What we know about it

    Small streams heat up and dry out quickly in heat waves; large rivers are more stable. Angling practice and a physical consideration.

    +1
  • Bottom by geologyLevel of evidence: Hypothesis

    Clays and loams, ŠGÚDŠ

    A fine-grained bottom is not typical of trout waters; the water clouds more easily.

    What we know about it

    Trout production is higher in limestone hard waters (Almodóvar et al. 2006), but in Irish streams geology did not change trout density and the structure of the channel decided (Lehane et al. 2004). The evidence diverges; the weight is small.

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

    −1

Life by the water0

  • Aquatic insect hatchesLevel of evidence: Anglers' practice

    0.0× the average month, 0 of 16 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

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)
  • Nitrogen in groundwater
  • Harmful substances in groundwater
  • Iron in groundwater
  • Chlorides in groundwater
  • Cold groundwater
  • Wastewater treatment plants
  • Invasive species nearby

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.
Surface water, 2024
within the standardno unmet standard at the nearest SHMÚ site

Surface water: nearest monitoring site

ÚKČ Košice, belowHornád, river km 23.5 · 2.9 km from the fishing district
no unmet standard
2022202320242025

In the yearbooks for 2022 to 2025 this site has no unmet indicator.

The location of the site is only approximate (based on the water body), so the actual sampling point may be elsewhere on the watercourse.

  • standard not met
  • no unmet standard
  • site not in the yearbook
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 (7 stations)

  • Velka LodinaKošice district – surroundings · borehole or well · 0.2 km from the fishing district
    no exceedance in 2025
    2017 to 2025

    In the yearbooks 2017 to 2025 no exceedance of the standard is recorded at the station.

    Measured values, year 2025, sampling 21 Mar 2025
    • Nitrates9.1 mg/l
    • Ammonium< 0.01 mg/l
    • Nitrites0.02 mg/l
    • Iron0.003 mg/l
    • Chlorides1.3 mg/l
    • Aluminium10% of the standard
  • Lemesany-chabzanyPrešov district · borehole or well · 4.5 km from the fishing district
    natural substances only
    2017 to 2025

    Exceeded in 2025:

    • Manganese
    • Total iron
    Measured values, year 2025, sampling 9 Sep 2025 (2 samplings, the highest value of the year for each substance)
    • Nitrates< 1 mg/l
    • Ammonium0.27 mg/l
    • Nitrites< 0.01 mg/l
    • Iron4.81 mg/l
    • Chlorides54.8 mg/l
    • Arsenic82% of the standard
  • Druzstevna – P.h. – M. VieskaKošice district – surroundings · borehole or well · 4.9 km from the fishing district
    no exceedance in 2025
    2017 to 2025

    In the yearbooks 2017 to 2025 no exceedance of the standard is recorded at the station.

    Measured values, year 2025, sampling 5 Jun 2025
    • Nitrates10 mg/l
    • Ammonium< 0.01 mg/l
    • Nitrites< 0.01 mg/l
    • Iron0.016 mg/l
    • Chlorides11.9 mg/l
    • Aluminium15% of the standard
Show 4 more
  • Miklusovce – pod ObisiankouPrešov district · spring · 7.5 km from the fishing district
    no exceedance in 2025
    2017 to 2025

    In the yearbooks 2017 to 2025 no exceedance of the standard is recorded at the station.

    Measured values, year 2025, sampling 21 May 2025
    • Nitrates2.5 mg/l
    • Ammonium< 0.01 mg/l
    • Nitrites0.01 mg/l
    • Iron0.02 mg/l
    • Chlorides2.3 mg/l
    • Aluminium20% of the standard
  • Kavecany – Pstruznik 1Košice I district · spring · 9.4 km from the fishing district
    no exceedance in 2025
    2017 to 2025

    In the yearbooks 2017 to 2025 no exceedance of the standard is recorded at the station.

    Measured values, year 2025, sampling 18 Sep 2025 (2 samplings, the highest value of the year for each substance)
    • Nitrates28.5 mg/l
    • Ammonium< 0.01 mg/l
    • Nitrites< 0.01 mg/l
  • Opatka – Vo Vinic. Pot. DolnyKošice district – surroundings · spring · 9.7 km from the fishing district
    no exceedance in 2025
    2017 to 2025

    In the yearbooks 2017 to 2025 no exceedance of the standard is recorded at the station.

    Measured values, year 2025, sampling 21 Mar 2025
    • Nitrates4.5 mg/l
    • Ammonium< 0.01 mg/l
    • Nitrites0.02 mg/l
    • Iron< 0.002 mg/l
    • Chlorides< 1 mg/l
    • Aluminium15% of the standard
  • Presov-haniskaPrešov district · borehole or well · 9.9 km from the fishing district
    no exceedance in 2025
    2017 to 2025

    Last exceeded in 2023:

    • Chloroethene (vinyl chloride)
    Measured values, year 2025, sampling 9 Sep 2025 (2 samplings, the highest value of the year for each substance)
    • Nitrates13.5 mg/l
    • Ammonium< 0.01 mg/l
    • Nitrites0.03 mg/l
    • Iron0.008 mg/l
    • Chlorides63.8 mg/l
    • Aluminium10% 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).

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 136 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.
1 956 km²medium river
Average flow
17.4 m³/smodel value
Stream order (Strahler)
4middle course
Channel gradient
2.2 ‰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.

After rain the water quickly turns turbid and fish hunt more by smell.

  • Gravels 33%
  • Clays and loams 67%
Springs and outflows
2within 1 km

Springs and groundwater outflows bring cooler water into the watercourse in summer and warmer in winter; fish stay near them in extreme weather.

According to the geological map: fluviálne sedimenty: litofaciálne nečlenené nivné hliny, alebo piesčité až štrkovité hliny dolinných nív a nív horských potokov, holocén

The fishing district description states the bottom: gravel, bedrock, stony; 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 16 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 7 groundwater stations within 10 km of the fishing district (nearest 0.2 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

0.005mg/l

far below the standard

Standard 0.5 mg/l. Range 0.005 to 0.27 mg/l, 7 stations.

00.75

Nitrites

0.02mg/l

far below the standard

Standard 0.5 mg/l. Range 0.005 to 0.03 mg/l, 7 stations.

075

Nitrates

9.1mg/l

far below the standard

Standard 50 mg/l. Range 0.5 to 28.5 mg/l, 7 stations.

012

Oxygen

7.17mg/l

enough oxygen

Mark on the dial: 9 mg/l, the guideline for salmonid waters. Range 1.49 to 9.32 mg/l, 7 stations.

020

Water temperature

9.4°C

moderate

Range 7.9 to 11.3 °C, 7 stations.

510

pH

7.45

suitable for fish

Range 6.87 to 7.61, 7 stations.

08

Water hardness

2.92mmol/l

moderately hard

Range 1.83 to 6.65 mmol/l, 6 stations.

00.3

Iron

0.003mg/l

above the standard somewhere

Standard 0.2 mg/l. Range 0.001 to 4.81 mg/l, 6 stations. Above the standard: 1 of 6 (Lemesany-chabzany, 4.5 km from the fishing district).

00.075

Manganese

0.01mg/l

above the standard somewhere

Standard 0.05 mg/l. Range 0.001 to 2.27 mg/l, 6 stations. Above the standard: 1 of 6 (Lemesany-chabzany, 4.5 km from the fishing district).

0375

Chlorides

1.3mg/l

far below the standard

Standard 250 mg/l. Range 0.5 to 63.8 mg/l, 6 stations.

0375

Sulphates

27.3mg/l

far below the standard

Standard 250 mg/l. Range 14.7 to 137 mg/l, 6 stations.

0188

Conductivity

47.3mS/m

below the standard

Standard 125 mS/m. Range 31.7 to 119 mS/m, 7 stations.

0150%

Metals and metalloids

10% of standard

below the standard

Highest: Arsenic 8.2 µg/l (82% of the standard, 4.5 km from the fishing district). 6 stations.

0150%

Solvents and benzene

0% of standard

not detected

Below the limit of quantification: substances from this group were not detected in the samples. 2 stations.

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. 2 stations.

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.
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.

Fish, wildlife, plants and hazards around the waterWildlife 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 around the water. Wildlife, plants and hazards do not enter the fishing conditions score and are for information only. The name of a species leads to its page.

MallardBird

Mallard

many records
Most records: March.
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: March.
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.

Great egretBird

Great egret

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

A large white heron that hunts fish and frogs in the shallows. In Slovakia its numbers are rising, and in winter it can also be seen by watercourses.

Great cormorantBird

Great cormorant

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

A fish-eating bird. It nests at large reservoirs and in winter also stays on streams with open water.

Mute swanBird

Mute swan

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

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

Great crested grebeBird

Great crested grebe

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

A diving waterbird with a crest on its head. Hunts small fish and insects, nests on a floating nest in the reeds.

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.

MayfliesWildlife

Mayflies

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

An insect with aquatic larvae. Adults live only briefly and hatch all at once in swarms.

Fire salamanderWildlife

Fire salamander

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

Black with yellow spots. Lives in deciduous forests by clean mountain streams; the larvae develop in the stream.

Common toadWildlife

Common toad

protected speciesquite a 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: April.
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.

Grass snakeWildlife

Grass snake

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

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

Black alderPlant

Black alder

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

A riparian tree whose roots reach below the water surface.

Common reedPlant

Common reed

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

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

Broadleaf cattailPlant

Broadleaf cattail

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

A wetland plant with a brown cylindrical fruiting spike.

Yellow flag irisPlant

Yellow flag iris

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

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

Japanese knotweedInvasive plant

Japanese knotweed

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

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

Common duckweedPlant

Common duckweed

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

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

Brown bearRisk

Brown bear

higher riskprotected speciesa single record
Most records: June.
How to protect yourself

Lives in the mountain forests of northern and central Slovakia. Near water it hunts fish and drinks.

How to protect yourself: In mountain districts move noisily, do not leave fish, entrails or bait leftovers near your tent, and store food away from where you sleep. If you see a bear, do not run, talk calmly and back away slowly. Never approach the cubs.

Castor bean tickRisk

Castor bean tick

to be reckoned withquite a few records
Most records: October.
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.

MosquitoesRisk

Mosquitoes

to be reckoned withquite a few records
Most records: August.
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.

Common viperRisk

Common viper

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

A venomous snake that basks on rocky slopes, in wetlands and at forest edges near water.

How to protect yourself: It is shy and bites only when threatened. On rocky banks do not reach with your hand between the stones, and wear sturdy footwear. After a bite stay calm, do not move the affected limb and call 112.

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.

Giant hogweedRisk

Giant hogweed

to be reckoned withinvasive speciesa few records
Most records: March.
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.

Wild boarRisk

Wild boar

to be reckoned witha few records
Most records: January.
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.

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

Animal and plant catalog

Source: GBIFUpdated 6 Nov 2026 16:16

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

medium

Common for most of Slovakia.

08

Uranium (eU)

2.2ppm

common

Typical background of the rocks.

020

Thorium (eTh)

7.7ppm

below the crustal average

Natural background of the rocks.

04

Potassium (K)

1.50%

below the crustal average

Natural background of the rocks.

0150

Gamma radiation

51nGy/h

around the world average

Natural background of the bedrock.

SVJZ

Magnetic anomaly (ΔT)

-52nT

below 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 250 m

fault nearby

Tectonic fault on the geological map.

Springs and outflows

2

groundwater by the watercourse

Within 1 km.

detected at the surface 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.
Ličartovce – cannot be estimated (1.7 km from the water)Trebejov – cannot be estimated (2.9 km from the water)Družstevná pri Hornáde – GTB-1 – non-spa (8.2 km from the water)a1 (3.6 km from the water)a1 (6.3 km from the water)a1 (7.6 km from the water)a1 (8.7 km from the water)a1 (8.8 km from the water)a1 (9.3 km from the water)a1 (9.7 km from the water)Trebejov – dolomite (2.9 km from the water)Trebejov – building stone (2.9 km from the water)Drienov – brick raw materials (4.5 km from the water)Družstevná pri Hornáde – Malá Vieska – dolomite (4.9 km from the water)Trebejov – dolomite (2.8 km from the water)Trebejov – building stone (2.8 km from the water)Drienov – brick raw materials (4.5 km from the water)Družstevná pri Hornáde – Malá Vieska – dolomite (4.9 km from the water)Trebejov – dolomite (2.8 km from the water)Veľká Lodina – Humenec (613 m n. m.) – building stone – granodiorite (210 m from the water)Obišovce – building stone – quartzite (1.0 km from the water)Kysak – building stone – dolomite (1.1 km from the water)Veľká Lodina – Fe ores – hematite, Cu ores (1.2 km from the water)Veľká Lodina – Ždiar (579,0) – Somár (627,0) – building stone – granodiorite (1.6 km from the water)Ličartovce – building stone – arkosic conglomerate (3.0 km from the water)Ružín, Malá Lodina – general geology (370 m from the water)Sopotnica – general geology (790 m from the water)TREBEJOV – Landslides (440 m from the water)OBISOVCE – Landslides (1.2 km from the water)– Landslides (1.3 km from the water)– Landslides (1.4 km from the water)KYSAK – Landslides (1.6 km from the water)– Landslides (2.0 km from the water)LICARTOVCE – Landslides (2.6 km from the water)– Landslides (2.7 km from the water)Malá Lodina – Landslides (2.8 km from the water)– Landslides (2.8 km from the water)Kysak – širokoprofilový vrt (Ø vŕtania nad 600 m (10 m from the water)Kysak – širokoprofilový vrt (Ø vŕtania nad 600 m (50 m from the water)Kysak – úzkoprofilový vrt s obyčajnou pitnou a ú (60 m from the water)Kysak – širokoprofilový vrt (Ø vŕtania nad 600 m (70 m from the water)Kysak – úzkoprofilový vrt s obyčajnou pitnou a ú (90 m from the water)Veľká Lodina – úzkoprofilový vrt s obyčajnou pitnou a ú (100 m from the water)Kysak – negative borehole (110 m from the water)Veľká Lodina – úzkoprofilový vrt s obyčajnou pitnou a ú (110 m from the water)Veľká Lodina – úzkoprofilový vrt s obyčajnou pitnou a ú (150 m from the water)Veľká Lodina – úzkoprofilový vrt s obyčajnou pitnou a ú (210 m from the water)Veľká Lodina – úzkoprofilový vrt s obyčajnou pitnou a ú (230 m from the water)Kysak – úzkoprofilový vrt s obyčajnou pitnou a ú (340 m from the water)Kysak – úzkoprofilový vrt s obyčajnou pitnou a ú (390 m from the water)Obišovce – úzkoprofilový vrt s obyčajnou pitnou a ú (400 m from the water)Kysak – širokoprofilový vrt (Ø vŕtania nad 600 m (640 m from the water)Malá Lodina – úzkoprofilový vrt s obyčajnou pitnou a ú (1.3 km from the water)Malá Lodina – úzkoprofilový vrt s obyčajnou pitnou a ú (1.5 km from the water)Ličartovce – úzkoprofilový vrt s obyčajnou pitnou a ú (1.5 km from the water)Malá Lodina (1.7 km from the water)Malá Lodina – úzkoprofilový vrt s obyčajnou pitnou a ú (1.7 km from the water)Ličartovce – širokoprofilový vrt (Ø vŕtania nad 600 m (1.8 km from the water)Lemešany-Rozvodňa – úzkoprofilový vrt s obyčajnou pitnou a ú (1.8 km from the water)Obišovce – úzkoprofilový vrt s obyčajnou pitnou a ú (1.9 km from the water)Lemešany – úzkoprofilový vrt s obyčajnou pitnou a ú (1.9 km from the water)Lemešany-Rozvodňa – úzkoprofilový vrt s obyčajnou pitnou a ú (2.0 km from the water)Trebejov – úzkoprofilový vrt s obyčajnou pitnou a ú (2.1 km from the water)Lemešany – úzkoprofilový vrt s obyčajnou pitnou a ú (2.1 km from the water)Ličartovce – úzkoprofilový vrt s obyčajnou pitnou a ú (2.1 km from the water)Lemešany – širokoprofilový vrt (Ø vŕtania nad 600 m (2.2 km from the water)Trebejov – úzkoprofilový vrt s obyčajnou pitnou a ú (2.2 km from the water)Lemešany – úzkoprofilový vrt s obyčajnou pitnou a ú (2.2 km from the water)Ličartovce – úzkoprofilový vrt s obyčajnou pitnou a ú (2.4 km from the water)Lemešany – úzkoprofilový vrt s obyčajnou pitnou a ú (2.4 km from the water)Ličartovce – širokoprofilový vrt (Ø vŕtania nad 600 m (2.5 km from the water)Lemešany – úzkoprofilový vrt s obyčajnou pitnou a ú (2.5 km from the water)Ličartovce – širokoprofilový vrt (Ø vŕtania nad 600 m (2.6 km from the water)Ličartovce – úzkoprofilový vrt s obyčajnou pitnou a ú (2.6 km from the water)Trebejov – úzkoprofilový vrt s obyčajnou pitnou a ú (2.6 km from the water)Lemešany – monitoring borehole (2.7 km from the water)Trebejov – širokoprofilový vrt (Ø vŕtania nad 600 m (2.7 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (30 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (70 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (90 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (110 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (160 m from the water)prameň – Groundwater springs (190 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (240 m from the water)vodárensky využívaný a monitorovaný prameň – Groundwater springs (260 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (280 m from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (290 m from the water)prameň – Groundwater springs (430 m from the water)prameň – Groundwater springs (690 m from the water)prameň – Groundwater springs (710 m from the water)vodárensky využívaný prameň – Groundwater springs (740 m from the water)prameň – Groundwater springs (860 m from the water)prameň – Groundwater springs (910 m from the water)prameň – Groundwater springs (940 m from the water)prameň – Groundwater springs (1.1 km from the water)prameň – Groundwater springs (1.1 km from the water)prameň – Groundwater springs (1.2 km from the water)prameň – Groundwater springs (1.2 km from the water)prameň – Groundwater springs (1.2 km from the water)prameň – Groundwater springs (1.2 km from the water)prameň – Groundwater springs (1.3 km from the water)prameň – Groundwater springs (1.3 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.3 km from the water)prameň – Groundwater springs (1.4 km from the water)prameň – Groundwater springs (1.4 km from the water)vodárensky využívaný prameň – Groundwater springs (1.4 km from the water)prameň – Groundwater springs (1.4 km from the water)existujúci hydrogeologický vrt – Hydrogeological boreholes (1.5 km from the water)prameň – Groundwater springs (1.5 km from the water)prameň – Groundwater springs (1.5 km from the water)prameň – Groundwater springs (1.5 km from the water)prameň – Groundwater springs (1.5 km from the water)vodárensky využívaný prameň – Groundwater springs (1.6 km from the water)prameň – Groundwater springs (1.6 km from the water)prameň – Groundwater springs (1.6 km from the water)prameň – Groundwater springs (1.6 km from the water)prameň – Groundwater springs (1.6 km from the water)Obišovce, chatová osada, 900m Z od K483 – source (110 m from the water)Veľká Lodina, prameň č. 29, 850 m SSZ od železni – source (260 m from the water)Veľká Lodina, 1300m J od K613 – source (350 m from the water)Kysak, 1400m ZJZ od K239 – source (500 m from the water)2000m V od K613 Humenec – source (530 m from the water)Kysak, dolina pod hradom, 400m J od K501 – source (620 m from the water)Kysak, prameň č. 19, 350 m J od K501 Hrad – source (740 m from the water)Kysak, prameň č. 18, 870 m Z od železničnej stan – source (860 m from the water)Veľká Lodina, 1300m SV od K788 Prielohy – source (1.1 km from the water)Obišovce, prameň č. 7, 700 m ZSZ od K359 – source (1.3 km from the water)Kysak, prameň č. 20, 850 m VSV od K657 Stadlo – source (1.4 km from the water)Obišovce, dolina Svinky ,300m V od K259 – source (1.4 km from the water)Veľká Lodina, 1600m SZ do K788 Prielohy – source (1.5 km from the water)600m JZ od K687 Tlstá – source (1.5 km from the water)Veľká Lodina, 1400m SZ od K613 – source (1.5 km from the water)Kysak, prameň č. 21, 800 m V od K657 Stadlo – source (1.6 km from the water)Kysak, prameň č. 22, 700 m V od K657 Stadlo – source (1.7 km from the water)Veľká Lodina, prameň č. 31, 800 m S od K500 Boks – source (1.7 km from the water)Kysak, prameň č. 17a, 250 m Z od K309 – source (1.7 km from the water)Trebejov, č.d. 44, 2500m SZ od K376 – well (2.1 km from the water)Ružín – dolina Veľký Ružínok, prameň č. 49 – source (2.2 km from the water)Veľký Ružínok, 2000m V od K781 – source (2.3 km from the water)800m VJV od K700 Somár – source (2.6 km from the water)dolina Svinky, 1700m SV od K687 – source (2.6 km from the water)Malá Lodina, 2200m JZ od K700 – source (2.6 km from the water)Trebejov, č.d. 5, 2500m ZSZ od K376 – well (2.7 km from the water)1200m SV od K Biela skala – source (2.7 km from the water)Ružín – dolina Veľký Ružínok, prameň č. 50 – source (2.7 km from the water)Malá Lodina, prameň č. 32, 1200 m S od K724 – source (2.8 km from the water)Trebejov ,č.d. 26, 2200m ZSZ od K376 – well (2.9 km from the water)zlato 1 ks – gold (60 m from the water)zlato 2 ks – gold (880 m from the water)zlato 1 ks – gold (960 m 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 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.

510

Water according to the atlas

pH 8.3modelled estimate

water type Ca–Mg–HCO₃

Mineralisation 393 mg/l, moderately hard water (13.7 °dH). Interpolation of measurements from the Geochemical Atlas of Slovakia, not a measurement in the stream.

Elements in river sediment

7 from 15elements in the top 10 %

highest: Arsenic 72.9 mg/kg

Position of the highest-ranked element among the sample points on streams in Slovakia: percentile 95. Interpolation of the Geochemical Atlas of river sediments.

1 km2 km45 °C75 °C

Heat underfoot

45°C at 1,000 m depth

At a depth of 2,000 m about 75 °C (increase of 30 °C per kilometre). Atlas of Geothermal Energy of Slovakia.

Gold in river sediment

3samples with gold

14 ore minerals in the sediment

Up to 2 grains in one sample (880 m from the water). Panning prospecting counted gold grains in a concentrate from river sediment.

Trace elements in the stream water

2 from 10indicators in the top 5 %

highest: Chromium 9.30 μg/l

Position of the highest measured value in the distribution of all surface water samples in Slovakia: percentile 97 (Svinka).

Boreholes and groundwater analyses

111boreholes within 3 km

326 water analyses nearby

Of these, 103 have an archive report from Geofond. The boreholes are hydrogeological, geological, engineering-geological and other.

0 °C120

Geothermal energy

30°C at the wellhead

1 geothermal borehole within 10 km

Warmest: Družstevná pri Hornáde – GTB-1, 8.2 km from the water.

Environmental burdens and landfills

2sites within 3 km

2 landfills

No environmental burden is registered within 3 km; landfills are only recorded.

Deposits and ore occurrences

15records within 5 km

9 deposits, 6 ore occurrences

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

Landslides and slope deformations

10areas within 3 km

1 active

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

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

2.0from 9

quiet field

Latest measurement (9 Nov 2026 13:00). 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 149 days old (13 Jun 2026) because the fishing district was cloud-covered.

Sentinel-2 satellite image of the surroundings of watercourse Hornád č. 2a from 19 Apr 2026, Water (NDWI)
Sentinel-2. Contains modified Copernicus Sentinel data 2026.

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.
1 % of areaClean surface

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

0.00.51.01.530 Nov3 Feb9 Apr13 Jun
Surface overgrowth trend: from 30 Nov 13:00 to 13 Jun 14:00. Latest 1%, lowest 0, highest 1%.

Since 30 Nov 2025: lowest 0% (5 Dec 2025), highest 1% (25 Mar 2026).

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

Sentinel-2, 13 Jun 2026, 59% 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.
0 % 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, 13 Jun 2026, 59% of the area cloud-free

Data have been stored since 21 Oct 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 2019 to 2025: 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 Hornád č. 2a from 2019
2019imaged 15 Jun 2019
Aerial image of fishing district Hornád č. 2a from 2022
2022imaged 8 Oct 2022
Aerial image of fishing district Hornád č. 2a from 2025
2025imaged 3 Jul 2025

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.