Fishing conditions score, the best window of the day and fishing districts from the best conditions Low activity · average of one fishing district 15:00–17:00 VN Veľké Kozmálovce, window score 17. The score is an estimate of conditions based on weather, water and surroundings, not a bite forecast. Recalculated at 04:04. The course of the watercourse and its fishing districts. You can switch the line color to today's conditions, quality or any other parameter. Detailed filtersregion, district, riverbed, depth, shading, satellites, water chemistry and pollution, fish, geology Move the map with two fingers. In full-screen mode one finger is enough. The score is an estimate of conditions based on weather, water and surroundings, not a bite forecast. For each fishing district you can see what it is made of, how well it is supported by data and where the data comes from. Terrain height along the fishing district and the approximate water level. Reservoir This is a reservoir, so the watercourse is not assessed here: the water has no current, fall or gradient. The chart shows the terrain height along the fishing district. Source: Open Topo Data (eudem25m), 4 Nov 2026. The height is approximate (error of a few metres). Loading the 3D terrain model… 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. 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. Water quality according to SHMÚ, wastewater treatment plants near the fishing districts and groundwater nearby 1 of 1 fishing district with measurements has groundwater nearby with a value above the limit for at least one indicator. Source: SHMÚ (yearbooks on surface and groundwater quality), the register of wastewater treatment plants from VÚVH and the EEA. A SHMÚ site is assigned to a fishing district by the same watercourse name and by distance; the yearbook lists the sites that failed the standard, so a missing site is not proof of clean water. Metals and gold in river sediments and water, old mine workings and deposits, boreholes with archive reports, geothermal energy, environmental burdens and landslides around the stream The overview is based on public registers and atlases of the State Geological Institute of Dionýz Štúr. The search covers a zone around the water of all fishing districts of the stream (4 km of line in total): stream samples within 1 km, boreholes, mine workings and burdens within 3 km, ore occurrences within 5 km, geothermal sources within 10 km. Young sediments100% of the water line Young unconsolidated sediments; fine material easily washes into the stream during rain. Geological Map of Slovakia 1:50,000. pH 7.5modelled estimate water type Ca–Mg–HCO₃–SO₄ Mineralisation 285 mg/l, moderately hard water (9.2 °dH). Interpolation of measurements from the Geochemical Atlas of Slovakia, not a measurement in the stream. 8 from 15elements in the top 10 % highest: Zinc 331 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. 55°C at 1,000 m depth heat flow 75 mW/m² At a depth of 2,000 m about 95 °C (increase of 40 °C per kilometre). Atlas of Geothermal Energy of Slovakia. 57nGy/h dose rate percentile 80 in Slovakia Natural background from rocks and soil (potassium, uranium, thorium), not a value measured at the water. Airborne gamma-ray spectrometry by ŠGÚDŠ. 1object within 3 km Nearest: Halda Rybník nad Hronom (spoil heap), 460 m from the water. 0samples with gold No gold was found in river sediment samples within 1 km of the water. The samples do not cover every stream, so this does not mean there is no gold here. 2 from 8indicators in the top 5 % highest: Arsenic 13.0 μg/l Position of the highest measured value in the distribution of all surface water samples in Slovakia: percentile 97 (Hron). 159boreholes within 3 km 258 water analyses nearby Of these, 159 have an archive report from Geofond. The boreholes are hydrogeological, geological, engineering-geological and other. – No geothermal borehole or spring is recorded within 10 km. 14sites within 3 km 1 environmental burden, 13 landfills Nearest burden: Tlmače – areál SES, 750 m from the water. Proximity does not mean that substances leak from the site into the water. 5records within 5 km 2 deposits, 3 ore occurrences Geofond registers, the metallogenetic map and the mineral resources map. 0areas within 3 km Documented landslides in the Geofond register. A landslide into a stream can cloud the water and change the bed. Which rock lies beneath the water line (Geological Map of Slovakia 1:50,000), how old it is, how thick the Quaternary cover is and in which tectonic unit the water flows. The bedrock decides the hardness of the water, the bottom, the turbidity after rain and the abundance of springs. The points follow the water line (for a stream and a basin, fishing district after fishing district). The strip is a cross-section by distance, not a map; the width of a section corresponds to the number of points. marker on the bar: share among all sample points on streams in Slovakia Young sediments: Young unconsolidated sediments; fine material easily washes into the stream during rain. marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia The map covers 1 of 2 points on the water line. Streams and rivers are fed by groundwater. Hydrogeological maps show in which rocks the water is stored, how permeable they are and what the water in them is like. The data come from ŠGÚDŠ maps, not from measurements at a particular water. marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia Modelled composition of the water in the area the fishing district line runs through. The rasters of the Geochemical Atlas of Slovakia (surface waters) are an interpolation of measurements in sampled streams, so they show the typical background of the area, not a measurement in a particular stream. pH 7.54typical range Most rivers and streams in Slovakia have a pH of 6.5 to 8.5. More acidic water is found in streams on acidic rocks (granites, quartzites), more alkaline water near limestones. 9.2°dH, moderately hard Sum of calcium and magnesium (1.64 mmol/l). Hard water is buffered and its pH changes more slowly; soft water is more sensitive to acid rain. 285mg/l mineralisation Total amount of dissolved minerals. Clean mountain water has tens of mg/l, lowland and limestone waters hundreds. Water type by dominant ions: Ca–Mg–HCO₃–SO₄ Shares are in equivalents, the usual way of comparing the composition of waters. dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile) The Geochemical Atlas of Slovakia (river sediments) describes what the river carries in the fine material on its bed. Sediment collects metals from rocks, ore occurrences and past mining and industry. It is not a legal limit or a health risk assessment: it shows how an element on this stream ranks among streams in Slovakia. dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile) Airborne gamma-ray spectrometry by ŠGÚDŠ measures radiation from potassium, uranium and thorium in rocks and soil. Granites and some acidic volcanic rocks have the highest values, limestones and floodplains the lowest. Caesium-137 is a remnant of fallout from the Chernobyl accident and nuclear weapons tests. 57nGy/h in air range 55 to 60 nGy/h Natural background from rocks and soil; higher over granites and some acidic volcanic rocks, lower over limestones and floodplains. medium Radon is a natural gas from rocks. The risk concerns buildings and cellars, not the water in the stream; it shows what the bedrock is like. dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile) marker on the bar: share among all sample points on streams in Slovakia Maps of the magnetic field and gravity (ŠGÚDŠ) reveal what lies beneath the sediments and the surface: volcanic bodies, faults and crustal thickness. For an angler they are interesting indirectly: they show where the bedrock changes, and with it the water. +90nT range 89 to 91 nT Deviation of the Earth's magnetic field from its surroundings. Positive and negative anomalies reveal rocks with magnetite (basalts, basic volcanic rocks) and boundaries in the bedrock. -17mGal residual −6.1 mGal Negative values lie over thick sediments and under mountains (light crust), positive over dense rocks and thinner crust. It shows the structure of the Earth's crust, not the water. The Atlas of Geothermal Energy of Slovakia records rock temperature and heat flow from the Earth's interior. It is the potential of the area, not the actual warmth of the water in the stream. Specific geothermal boreholes and springs near this water are in the geothermal energy section below. 55 / 95 °Cat depths of 1,000 and 2,000 m increase of 40 °C per km The line shows the rock temperature; the dotted part is only an extension to the surface. Heat flow 75 mW/m². marker on the bar: share among all sample points on streams in Slovakia A basin is not just water: slope and elevation determine the speed of runoff, climate the temperature and amount of water, and soils what is washed into the stream. The data come from the geomorphological division, climatic-geographical types and soil maps of ŠGÚDŠ. marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia marker on the bar: share among all sample points on streams in Slovakia Where the nearest mine workings, deposits, burdens, geothermal boreholes and gold finds are. Groups can be switched off. 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. Arsenic, antimony, cadmium, lead, copper, zinc and other elements in samples from rivers and streams (Geochemical Atlas of Slovakia, surface waters, 2015). The bar shows where the highest value lies among all samples in Slovakia; the light marker is the median of the samples at this water. Highest value: Hron1997, 110 m from the water. Comparison: percentile 97 of all samples in Slovakia. Highest value: Perec, kanál1997, 680 m from the water. Comparison: percentile 95 of all samples in Slovakia. Highest value: Hron1997, 150 m from the water. Comparison: percentile 86 of all samples in Slovakia. Highest value: Perec, kanál1997, 680 m from the water. Comparison: percentile 46 of all samples in Slovakia. Highest value: Perec, kanál1997, 680 m from the water. Comparison: percentile 43 of all samples in Slovakia. Highest value: Perec, kanál1997, 680 m from the water. Comparison: percentile 37 of all samples in Slovakia. Highest value: Perec, kanál1997, 680 m from the water. Comparison: percentile 34 of all samples in Slovakia. Highest value: Perec, kanál1997, 680 m from the water. Comparison: percentile 32 of all samples in Slovakia. Basic water chemistry: which rocks the minerals in it come from. Highest value: Hron1997, 50 m from the water. Comparison: percentile 74 of all samples in Slovakia. Hydrogeochemical objects (analyses of springs and boreholes), the geochemical atlas of groundwater (1996) and radiohydrochemical sampling. Groundwater feeds streams, so its composition also affects the water in the stream. Highest value: studňa1992, 1.4 km from the water. Comparison: percentile 99 of all samples in Slovakia. Highest value: studňa1992, 1.4 km from the water. Comparison: percentile 99 of all samples in Slovakia. Highest value: prameň1992, 2.3 km from the water. Comparison: percentile 99 of all samples in Slovakia. Highest value: studňa1992, 2.0 km from the water. Comparison: percentile 96 of all samples in Slovakia. Highest value: studňa1992, 1.3 km from the water. Comparison: percentile 96 of all samples in Slovakia. Highest value: vrt1992, 700 m from the water. Comparison: percentile 95 of all samples in Slovakia. Highest value: vrt, 2.2 km from the water. Comparison: percentile 95 of all samples in Slovakia. Highest value: studňa1992, 2.2 km from the water. Comparison: percentile 93 of all samples in Slovakia. Highest value: vrt1992, 2.1 km from the water. Comparison: percentile 92 of all samples in Slovakia. Highest value: vrt1992, 560 m from the water. Comparison: percentile 91 of all samples in Slovakia. Highest value: prameň1992, 2.3 km from the water. Comparison: percentile 50 of all samples in Slovakia. Highest value: studňa1992, 2.2 km from the water. Comparison: percentile 46 of all samples in Slovakia. Old mine workings outside mining areas (Geofond register), deposits and mining areas, and the metallogenetic map. Gold, silver and other metals near streams can get into sediments and water. Register of hydrogeological boreholes, other boreholes and geothermal boreholes. Each borehole has a report in the Geofond archive (geological profiles, pumping tests, chemical analyses of the water); the report number is in the table. 159 boreholes in the 3 km zone, of which 85 hydrogeological and 74 other; with an archive report number 159. Recorded environmental burdens (industrial sites, landfills, mining), the register of waste landfills and monitoring of anthropogenic sediments (industrial sludge). It is a list of places, not a measurement of water pollution. Data: © ŠGÚDŠ (https://www.geology.sk), downloaded 8 Nov 2026. Details in the Methodology. Who manages the fishing districts and where they are Hron basin
By the water now
Today on the VN Veľké Kozmálovce watercourse
Average of the watercourse's fishing districts
Best window today
Map and fishing districts of the watercourse
Elevation profile: reservoir
Terrain in 3D
Historical images
Water pollution on the VN Veľké Kozmálovce watercourse
Problem treatment plants near the fishing districts1 treatment plant within 2 km of the fishing district
Groundwater: measured valuestypical value from stations within 10 km, 2025
Geology and geochemistry of the VN Veľké Kozmálovce stream
Rock under the water
Water according to the atlas
Elements in river sediment
Heat underfoot
Natural gamma radiation
Old mine workings
Gold in river sediment
Trace elements in the stream water
Boreholes and groundwater analyses
Geothermal energy
Environmental burdens and landfills
Deposits and ore occurrences
Landslides and slope deformations
Geological structure beneath the water
Geological age of the rocks
Most common rock units
System Age Unit Points Quaternary Pleistocene proluvial sediments: clay and sandy gravel with rock fragments in low alluvial cones 1× Quaternary cover
Tectonic division
Neotectonic units
Direction of neotectonic movements
Regional geological division
Regional geological division (subunits)
Engineering-geological districts
Engineering-geological formations
Susceptibility of the area to slope deformations
Hydrogeology: aquifers and groundwater
Aquifer rocks (hydrogeological map 1:200,000)
Aquifer type
Type of permeability (basic hydrogeological map 1:50,000)
Hydrogeological function
Main hydrogeological region
Genetic type of groundwater
Chemical type of groundwater
Groundwater quality class
Geothermal groundwater bodies
Surface water chemistry according to the atlas
Water acidity
Water hardness
Dissolved substances
Ionic composition of the water
Major ions
50.5 mg/lpercentile 6111.8 mg/lpercentile 579.75 mg/lpercentile 532.53 mg/lpercentile 4212.1 mg/lpercentile 3945.8 mg/lpercentile 32135 mg/lpercentile 280.0594 mg/lpercentile 16Nutrients and organic pollution
0.402 mg/lpercentile 8310.7 mg/lpercentile 750.375 mg/lpercentile 733.67 mg/lpercentile 61Metals
19.3 μg/lpercentile 860.206 mg/lpercentile 76130 μg/lpercentile 6861.3 μg/lpercentile 68Elements in river sediments
Potentially toxic and trace elements
331 mg/kgpercentile 9548.9 mg/kgpercentile 950.980 mg/kgpercentile 940.653 mg/kgpercentile 9369.6 mg/kgpercentile 9327.1 mg/kgpercentile 930.929 mg/kgpercentile 935.83 mg/kgpercentile 910.483 mg/kgpercentile 8912.2 mg/kgpercentile 8793.5 mg/kgpercentile 854.02 mg/kgpercentile 820.236 mg/kgpercentile 4749.8 mg/kgpercentile 1616.5 mg/kgpercentile 16Major elements (iron, aluminium, calcium, magnesium, potassium, sodium, titanium, manganese, phosphorus)
6.83 %percentile 833.31 %percentile 761.02 %percentile 741,023 mg/kgpercentile 704,886 mg/kgpercentile 661.59 %percentile 620.970 %percentile 58913 mg/kgpercentile 572.10 %percentile 51Further elements (barium, strontium, lithium, rubidium, zirconium, yttrium, cerium, boron, beryllium, gallium)
40.6 mg/kgpercentile 891.97 mg/kgpercentile 8117.2 mg/kgpercentile 76521 mg/kgpercentile 75169 mg/kgpercentile 7531.5 mg/kgpercentile 6963.3 mg/kgpercentile 6488.3 mg/kgpercentile 49369 mg/kgpercentile 3844.7 mg/kgpercentile 15Natural radioactivity and radon
Gamma radiation dose rate
Radon risk of the bedrock
8.90 ppm83th percentile2.85 ppm76th percentile1.42 %percentile 751,830 Bq/m²percentile 64Radon risk by isopleths
Geophysical fields: magnetics and gravity
Magnetic anomaly
Bouguer gravity anomaly
Geothermal potential
Rock temperature with depth
Geothermal groundwater bodies beneath the water line
Relief, climate and soils
Climatic-geographical types
Susceptibility of soils to acidification
Lithogeochemical types
Map of the corridor
Trace elements in surface waters
Major ions, mineralisation and pH
Groundwater: chemistry, water types and radioactivity
Chemical water types nearby
Water quality class according to the hydrogeochemical map
Metals in groundwater
Radon in waters
Type of site Samples Highest radon Median well 13 25,3 Bq/l 9.27 Bq/l water source for public supply 3 27,0 Bq/l 19.7 Bq/l stream, river 4 5,70 Bq/l 1.58 Bq/l source 1 5,40 Bq/l 5.40 Bq/l Mine workings, deposits and ore occurrences
Types of mining objects
Nearest old mine workings
Name Type Mined Ended From the water Halda Rybník nad Hron spoil heap building stone 460 m Deposits and mining areas
Deposit Mineral Status and organisation From the water Rybník nad Hronom building stone Mined deposit – ČESATO, s.r.o. 490 m Rybník nad Hronom building stone Mined deposit – ČESATO, s.r.o. 490 m Boreholes and Geofond archive reports
Borehole depths
Nearest boreholes
Site Type Depth Archive report From the water Hron-weir, Veľké Kozmálovce wide-diameter borehole 33.5 m 50584 134Aa62.pdf20 m S-7a mapping 40.0 m 253920 m Veľké Kozmálovce wide-diameter borehole 12.0 m 50584 134Aa61.pdf80 m S-1 mapping 40.0 m 253990 m S-2 mapping 40.0 m 2539110 m Tlmače wide-diameter borehole 4.8 m 20127 134Aa32.pdf140 m S-7 mapping 40.0 m 2539170 m Tlmače 42.0 m 2027 134Aa6.pdf180 m S-9 mapping 40.0 m 2539190 m S-6 mapping 40.0 m 2539210 m Malé Kozmálovce monitoring borehole 0.0 m 92286 134Aa86.pdf220 m Tlmače negative borehole 3.7 m 2027 134Aa7.pdf240 m Environmental burdens, landfills and anthropogenic sediments
Environmental burdens
Site Activity Substance Classification From the water Tlmače – areál SES SK1000700P 750 m Waste landfills
Landfill Area Year established Monitoring From the water Veľké Kozmálovce – cintorín – Veľké Kozmálovce 1 500 m² 1970 – 440 m Malé Kozmálovce – obec – Malé Kozmálovce 100 m² – – 710 m Kozárovce – Kameňolom – Kozárovce – 1980 – 740 m Kozárovce – Rampy – Kozárovce 200 m² 1988 – 1.2 km Malé Kozmálovce – Rýha – Malé Kozmálovce 200 m² 1980 – 1.5 km Malé Kozmálovce – lom – Malé Kozmálovce 200 m² 1980 – 1.8 km Rameno Hron – Starý Tekov 500 m² 1985 – 2.3 km Kozárovce – Helena – Kozárovce 200 m² 1970 – 2.3 km How to read these data
Organizations and location
Organizations on the watercoursewho manages the fishing districts and what the conditions are there today
More watercourses nearby
8from 100
1445fishing districts
Map color
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lowerhigher
Cations (positive ions)
Anions (negative ions)
ArsenicAshigh (top 5 %)
highest 13.0 μg/lmedian 11.0 μg/l4 samples
AntimonySbhigh (top 5 %)
highest 4.00 μg/lmedian 3.50 μg/l4 samples
CopperCuslightly elevated
highest 4.00 μg/lmedian 3.00 μg/l4 samples
SeleniumSebelow half of Slovakia
highest 0.500 μg/lmedian 0.500 μg/l4 samples100 % below the limit of quantification
LeadPbbelow half of Slovakia
highest 2.50 μg/lmedian 2.50 μg/l4 samples100 % below the limit of quantification
BariumBabelow half of Slovakia
highest 30.0 μg/lmedian 25.0 μg/l4 samples
LithiumLibelow half of Slovakia
highest 5.00 μg/lmedian 5.00 μg/l4 samples100 % below the limit of quantification
ChromiumCrbelow half of Slovakia
highest 1.00 μg/lmedian 1.00 μg/l4 samples100 % below the limit of quantification
Silicon dioxideSiO2typical value
highest 17.7 mg/lmedian 15.3 mg/l4 samples
ArsenicAsextreme (top 1 %)
highest 115 μg/lmedian 3.60 μg/l18 samples11 % below the limit of quantification
AntimonySbextreme (top 1 %)
highest 4.30 μg/lmedian 0.650 μg/l18 samples22 % below the limit of quantification
CadmiumCdextreme (top 1 %)
highest 2.10 μg/lmedian 0.250 μg/l18 samples89 % below the limit of quantification
LeadPbhigh (top 5 %)
highest 4.00 μg/lmedian 1.00 μg/l18 samples39 % below the limit of quantification
AluminiumAlhigh (top 5 %)
highest 0.100 mg/lmedian 0.0400 mg/l18 samples6 % below the limit of quantification
SeleniumSehigh (top 5 %)
highest 2.90 μg/lmedian 0.500 μg/l18 samples56 % below the limit of quantification
LithiumLielevated (top 10 %)
highest 51.0 μg/lmedian 8.50 μg/l18 samples6 % below the limit of quantification
CopperCuelevated (top 10 %)
highest 5.10 μg/lmedian 1.00 μg/l18 samples
ZincZnelevated (top 10 %)
highest 699 μg/lmedian 69.5 μg/l18 samples
ChromiumCrelevated (top 10 %)
highest 2.40 μg/lmedian 0.600 μg/l18 samples44 % below the limit of quantification
IronFetypical value
highest 0.00500 mg/lmedian 0.00500 mg/l4 samples100 % below the limit of quantification
MercuryHgbelow half of Slovakia
highest 0.100 μg/lmedian 0.100 μg/l18 samples100 % below the limit of quantification
