Dataset description: The dataset reflects spatial delineation of monitored and unmonitored catchments used for the assessment of waterborne nutrients inputs to the Baltic Sea sub-basins (Baltic Sea Environmental Fact Sheet) in the HELCOM Pollution Load Compilation. Polygonal features in the dataset cover entire river catchments without distinguishing between sub-catchments located in upstream countries. Some countries even combine unmonitored and monitored parts of river catchments into a single catchment. The Source Code attribute in the dataset corresponds to the Source_Code in the Assessment data on waterborne input of nutrients dataset. The data is reported to the HELCOM Map and Data Service (MADS) and quality assured by Contracting Parties to HELCOM in accordance with the HELCOM Guidelines for the annual and periodical compilation and reporting of waterborne pollution inputs to the Baltic Sea (HELCOM PLC-Water Guideline). Dataset content: Polygonal feature class contains the following attributes: Sub-catchment code (subc_code): Unique code for river catchments and unmonitored areas Sub-catchment name (subc_name): Name of river catchment or unmonitored area River code (r_code): Unique code of the river included in HELCOM PLC assessment. Sub-basin code (subb_code): The Baltic Sea sub-basin where the river drains to. Country code (c_code): The Country on which territory the river mouth is located, for border rivers both are mentioned. Monitoring (monitoring): The monitoring status of the river (M=monitored and U=unmonitored). Marked as monitored only if the catchment has been monitored for the entire time series. Transboundary (transboundary): Listing all countries that have the rivers drainage area on its territory. Area km2 (area_km2): The total area of the catchment in square kilometres. Year (year). Country codes used in the dataset correspond to: DK-DENMARK; EE-ESTONIA; FI-FINLAND; DE-GERMANY; LV-LATVIA; LT-LITHUANIA; PL-POLAND; RU-RUSSIA; SE-SWEDEN. The Baltic Sea sub-basin codes used in the dataset are: ARC-ARCHIPELAGO SEA; BAP-BALTIC PROPER; BOB-BOTHNIAN BAY; BOS-BOTHNIAN SEA; GUF-GULF OF FINLAND; GUR-GULF OF RIGA; KAT-KATTEGAT; SOU-SOUND; WEB-WESTERN BALTIC. Visualization: Map of catchments in the HELCOM Pollution Load Compilation. Data update: Metadata is updated by HELCOM Secretariat annually by 1 April. The dataset is updated by HELCOM Secretariat annually by 1 April.

Dataset description: The dataset reflects spatial delineation of monitored and unmonitored sub-catchments used to compile data on inputs of nutrients and hazardous substances to the Baltic Sea sub-basins in the HELCOM Pollution Load Compilation. The sub-catchments are the smallest entities for which inputs of nutrients and hazardous substances to the Baltic Sea are reported. The sub-catchments are always located within borders of a single country and drain into a single Baltic Sea sub-basin. Sub-catchments may correspond to either monitored or unmonitored areas. Unmonitored sub-catchments may represent either unmonitored parts of river catchments or aggregated unmonitored areas (depending on the reporting format of each Contracting Party). Polygonal features in the dataset have attributes indicating whether a sub-catchment represents monitored or unmonitored area. A specific attribute indicates that the sub-catchment is in the upstream country of a transboundary river catchment. The data is reported to the HELCOM Map and Data Service (MADS) and quality assured by Contracting Parties to HELCOM in accordance with the HELCOM Guidelines for the annual and periodical compilation and reporting of waterborne pollution inputs to the Baltic Sea (HELCOM PLC-Water Guideline). Dataset content: Polygonal feature class contains the following attributes: Sub-catchment code (subc_code): unique HELCOM PLC code Sub-catchment name (subc_name): sub-catchment name corresponds to the name of the river or coastal area River code (r_code): unique HELCOM PLC code. Country code (c_code): DK; EE; FI; DE; LV; LT; PL; RU; SE; BY; UA; CZ; SK. Sub-basin code (subb_code): ARC; BAP; BOB; BOS; GUF; GUR; KAT; SOU; WEB. Monitoring (monitoring): monitored (M), unmonitored (U) Transboundary (transboundary): Field values are: TRANS (for downstream parts of transboundary rivers and border rivers), a country code (indicates the downstream country for upstream parts of transboundary rivers), or N/A (river is non transboundary). Area km2 (area_km2): sub-catchment area in km2 Year (year). Country codes used in the dataset correspond to: BY-BELARUS, CZ-CZECH REPUBLIC, DK-DENMARK; EE-ESTONIA; FI-FINLAND; DE-GERMANY; LV-LATVIA; LT-LITHUANIA; PL-POLAND; RU-RUSSIA; SK-SLOVAKIA; SE-SWEDEN; UA-UKRAINE. The Baltic Sea sub-basin codes used in the dataset are: ARC-ARCHIPELAGO SEA; BAP-BALTIC PROPER; BOB-BOTHNIAN BAY; BOS-BOTHNIAN SEA; GUF-GULF OF FINLAND; GUR-GULF OF RIGA; KAT-KATTEGAT; SOU-SOUND; WEB-WESTERN BALTIC. Visualization: Map layer of monitored and unmonitored areas. Map layer of transboundary and border rivers. Catchment areas of Baltic Sea sub-basins. Data update: Metadata is updated by HELCOM Secretariat annually by 1 April. The dataset is updated by HELCOM Secretariat annually by 1 April.

Dataset description: The dataset contains data on locations of river monitoring stations of nutrients and hazardous substances inputs to the Baltic Sea reported to the HELCOM Pollution Load Compilation (PLC-water) database. The stations are categorized as hydrological (only flow monitoring) and chemical (monitoring of chemical components). The data is reported to the HELCOM database and quality assured by Contracting Parties to HELCOM in accordance with the HELCOM Guidelines for the annual and periodical compilation and reporting of waterborne pollution inputs to the Baltic Sea (PLC-Water Guidelines). Dataset content: Station code (st_code): unique HELCOM PLC code Station name (st_name). River code (r_code): unique HELCOM PLC code. Sub catchment code (subc_code): unique HELCOM PLC code Country code (c_code): DK; EE; FI; DE; LV; LT; PL; RU; SE. Sub-basin code (subb_code): ARC; BAP; BOB; BOS; GUF; GUR; KAT; SOU; WEB. Station category (st_cat): hydrological (H) and chemical (C). Latitude (st_lat). Longitude (st_lon). Reporting year (year). Country codes used in the dataset correspond to: DK-DENMARK; EE-ESTONIA; FI-FINLAND; DE-GERMANY; LV-LATVIA; LT-LITHUANIA; PL-POLAND; RU-RUSSIA; SE-SWEDEN. The Baltic Sea sub-basin codes used in the dataset are: ARC-ARCHIPELAGO SEA; BAP-BALTIC PROPER; BOB-BOTHNIAN BAY; BOS-BOTHNIAN SEA; GUF-GULF OF FINLAND; GUR-GULF OF RIGA; KAT-KATTEGAT; SOU-SOUND; WEB-WESTERN BALTIC. Visualization: Map - point feature class. Legend visualizes two categories of monitoring station: hydrological, chemical. Data update: Metadata is updated by HELCOM Secretariat annually by 1 April. The dataset is updated by HELCOM Secretariat annually by 1 April.

Dataset description: The assessment dataset contains data on water flow and annual nutrient inputs (total nitrogen and phosphorous loads) from catchments and from point sources (municipal, industrial and aquaculture) directly discharging to the Baltic Sea sub-basins. The dataset is produced by regional experts (PLC implementation group) through statistical analysis and filling data gaps in the data reported by national experts to the HELCOM PLC-water database. The dataset includes actual (non-normalized), and water flow normalized annual inputs of total nitrogen (TN) and total phosphorus (TP) from monitored and unmonitored areas per Balic Sea sub-basin. It also contains data on total nitrogen (TN) and total phosphorus (TP) annual inputs from point sources (industrial, municipal and aquaculture) aggregated per country and per sub-basin discharging directly into the Baltic Sea sub-basins. The dataset is published as MS Excel workbook, consisting of several sheets. The sheets provide assessment data for flow, total nitrogen and total phosphorus, as well as background information on data treatment and aggregation. Spatial delineation of catchments is provided in the catchment dataset accessed through HELCOM Metadata Catalogue - (PLC) Assessment catchments (spatial data). Datasets can be related using Source_Code field. The dataset is used in HELCOM Baltic Sea Environmental Fact Sheet (BSEFS) on Waterborne nitrogen and phosphorus inputs and water flow to the Baltic Sea published annually. Dataset content: Excel workbook contains the following tables: AggregationsOfIncompleteRiverTi – the table enlists aggregation of monitored areas of sub-catchments with incomplete time-series with unmonitored areas (country specific), UnmonitoredAreasMergedInMonitor – the table enlists aggregation of unmonitored and monitored areas into unified catchments (country specific). OriginalRivers_Flow, OriginalRivers_TN, OriginalRivers_TP – time series of flows (m3/s) and total N and P (tonnes/year) inputs as reported to PLC-Water database for monitored rivers OriginalUnmonitored_Flow, OriginalUnmonitored_TN, OriginalUnmonitored_TP - time series of flows (m3/s) and total N and P inputs (tonnes/year) as reported to PLC-Water database for unmonitored areas Rivers_Flow (m3/s), Rivers_TN (tonnes/year), Rivers_TP (tonnes/year) - non-normalized inputs from rivers and unmonitored areas, Rivers_NormTN (tonnes/year), Rivers_NormTP (tonnes/year) - normalized inputs from rivers and unmonitored areas, Industry_TN (tonnes/year); Industry_TP (tonnes/year) – aggregated input from industrial point sources discharging directly into the Baltic Sea, Municipal_TN (tonnes/year); Municipal_TP (tonnes/year) – aggregated input from municipal WWTPs discharging directly into the Baltic Sea, Aquaculture_TN (tonnes/year); Aquaculture_TP (tonnes/year) – aggregated input from aquaculture discharging directly into the Baltic Sea. Tables under items 3-6 contain the following fields: Source_Code, Name, Country code, Basin code, 1995, …, 20XX Where water flow is given in m3s-1 and TN/TP tonnes year-1 for each year. Tables under items 7-9 contain the following fields: Country code, Basin code, 1995, …., 20XX Where TN/TP is given in tonnes year-1 for each year. Visualization: MS Excel table. PowerBI visualization tool Data update: Metadata is updated by HELCOM Secretariat annually by 1 July. The dataset is updated by HELCOM Secretariat annually by 1 July.

Dataset description: The dataset contains annually reported data on water flow, input of nutrients and selected hazardous substances to the Baltic Sea from monitored rivers and unmonitored areas within its catchment area. The data, obtained through national monitoring programmes, is reported by all Contracting Parties to the HELCOM (PLC-water) database as part of HELCOM Pollution Load Compilation (PLC) process. The input from transboundary rivers reflects the whole river catchment including its transboundary parts.. All data is quality assured and approved by Contracting Parties to HELCOM in accordance with the HELCOM Guidelines for the annual and periodical compilation and reporting of waterborne pollution inputs to the Baltic Sea (HELCOM PLC-Water Guideline). Dataset content: The dataset contains the following information: Source name. Name of monitored river or unmonitored area. Source code. The source code refers to the code used in the PLC-water database for the monitored or unmonitored sub-catchments. Country code. The country code indicates the country within the Baltic Sea drainage area (DK; EE; FI; DE; LV; LT; PL; RU; SE;). Sub-basin code. The sub-basin code refers to the Baltic Sea sub-basin used in HELCOM assessment of inputs of nutrients and hazardous substances (ARC; BAP; BOB; BOS; GUF; GUR; KAT; SOU; WEB). Parameter. Parameters reported by the contracting parties to the Helsinki Convention to assess riverine inputs of nutrients and selected hazardous substances. : AOX; BOD5; BOD7; Cd*; COD-Cr; COD-Mn; Cr; Cu; FLOW; Hg*; Ni; NNH4*; NNO2*; NNO3*; NNO3; NTOT*; Oil; Pb*; PPO4;* PTOT*; SPM; TOC; Zn. (tonnes/year or flow in m3/s). Year. Year of observation. *Mandatory parameters for annually reported riverine data. Other parameters are voluntary. Country codes used in the dataset correspond to: DK-DENMARK; EE-ESTONIA; FI-FINLAND; DE-GERMANY; LV-LATVIA; LT-LITHUANIA; PL-POLAND; RU-RUSSIA; SE-SWEDEN; The Baltic Sea sub-basin codes used in the dataset are: ARC-ARCHIPELAGO SEA; BAP-BALTIC PROPER; BOB-BOTHNIAN BAY; BOS-BOTHNIAN SEA; GUF-GULF OF FINLAND; GUR-GULF OF RIGA; KAT-KATTEGAT; SOU-SOUND; WEB-WESTERN BALTIC. Visualization: The dataset can be retrieved from the HELCOM PLC-Water database and visualized utilizing an online user interface. The following filters are available to generate the dataset: Source of input: monitored river, unmonitored area. Multiple selection possible Country: DENMARK; ESTONIA; FINLAND; GERMANY; LATVIA; LITHUANIA; POLAND; RUSSIA; SWEDEN. Multiple selection possible. Baltic Sea sub-basin: ARCHIPELAGO SEA; BALTIC PROPER; BOTHNIAN BAY; BOTHNIAN SEA; GULF OF FINLAND; GULF OF RIGA; KATTEGAT; SOUND; WESTERN BALTIC. Multiple selection possible. Year: the first and the last year of the data request (1995-20…) Parameter: AOX; BOD5; BOD7; Cd; COD-Cr; COD-Mn; Cr; Cu; FLOW; Hg; Ni; NNH4; NNO2; NNO23; NNO3; NTOT; Oil; Pb; PPO4; PTOT; SPM; TOC; Zn. Only one parameter can be selected. Data update: Metadata is updated by the HELCOM Secretariat annually by 1 April. The dataset is updated annually and becomes publicly available in accordance with PLC-Water Guidelines, which details the procedures for reporting data to the HELCOM pollution load compilation (PLC) and the release of PLC products based on reported data.