4f4c4942-4343-5764-6473-313631333730 English Natural Resources Wales Maes y Ffynnon Bangor LL57 2DW Wales opendata@cyfoethnaturiolcymru.gov.uk 2025-10-24T13:26:11.138Z NRW 1.0 wel British National Grid (EPSG:27700) Nutrient Sensitive Marine SAC Freshwater Catchments Nutrient Sensitive Marine SAC Freshwater Catchments Dalgylchoedd dŵr croyw ACA Morol sy'n sensitif i faetholion Nutrient sensitive Marine SAC freshwater catchments.lyr 2025-07-31 NRW_DS161370 The Nutrient sensitive Marine SAC freshwater catchments layer depicts the surface water freshwater catchments that discharge to Marine SAC’s supporting habitat features particularly sensitive to nutrient enrichment. Catchment polygons are split by Special Area of Conservation and receiving waterbody (Water Framework Directive Regulations, Transitional or Coastal waterbody). Please also see metadata number NRW_DS161371 "Marine SAC freshwater catchments requiring nitrogen neutrality" which is related. The Nutrient sensitive Marine SAC freshwater catchments layer depicts the surface water freshwater catchments that discharge to Marine SAC’s supporting habitat features particularly sensitive to nutrient enrichment. Catchment polygons are split by Special Area of Conservation and receiving waterbody (Water Framework Directive Regulations, Transitional or Coastal waterbody). Please also see metadata number NRW_DS161371 "Marine SAC freshwater catchments requiring nitrogen neutrality" which is related. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Area management/restriction/regulation zones and reporting units Environmental monitoring facilities Protected sites Utility and governmental services GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme MARINE FRESHWATER protected sites Special Areas of Conservation (SAC) (see also Candidate Special Areas of Conservation cSAC) NRW Thesaurus 2025-01-08 geonetwork.thesaurus.local.theme.converted_nrw-keywords Access to this data may be restricted. NRW may NOT publish or disseminate the data. NRW may provide access to this dataset on request, however, enquirers are advised to request access from Data Distribution © CNC/NRW All rights Reserved. Contains Ordnance Survey Data. Ordnance Survey Licence number AC0000849444. Crown Copyright and Database Right. Crown Copyright: Welsh Government. Data may only be re-used externally under provision and in line with the terms of a NRW licence Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights reserved. © Crown Copyright and Database Rights. Ordnance Survey Licence number AC0000849444, © Crown Copyright: Welsh Government. NRW Conditional English environment Wales (WLS) -5.311 -2.647 51.384 53.427 SeaVoX Vertical Co-ordinate Coverages 2013-02-05 creation unknown 2025-01-16 Marine SAC condition assessments published on NRW website: https://www.naturalresources.wales/guidance-and-advice/environmental-topics/wildlife-and-biodiversity/protected-areas-of-land-and-seas/condition-assessments-for-welsh-european-marine-sites-ems/?lang=en Geographic Information System Unknown ESRI Feature Class Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false The Nutrient sensitive Marine SAC freshwater catchments layer has been created in QGIS largely using the PCRaster toolset. Data sources from DataMapWales: - ‘LIDAR data download’ - comprising Welsh Govt LIDAR 2020-2023 - ‘Wales Boundary’ (High Water Mark), - ‘Wales National Marine Plan Boundary’ - (Normal Tidal Limit) - ‘SACs’ - ‘WFD Cycle 2 TraC Waterbodies’. All Open Government Data sources. Data Processing: (QGIS largely using PCRaster toolset) - Native resolution LIDAR Digital Terrain Model (DTM) geotiff data was resampled at 10m x 10m resolution. - DTM converted to PC raster format. - DTM clipped to High Water using Wales (High Water Mark) polygon. - DEM converted to Local Drain Direction (LDD) raster having filled pits in DTM (using ‘LDDcreate’ tool for both tasks) - LDD raster processed (using ‘pit’ tool) to identify drainage outlets to the DTM boundary, creating an ‘outlets’ raster. - LDD and Outlets rasters processed (using ‘catchments’ tool) to create upstream catchments flowing to the outlet points, one for each outlet. Created ‘catchments’ raster. - Converted Catchments raster to vector format. Tidying up and adding data attributes: - The Catchments vector layer was clipped using the National Marine Plan boundary (Normal Tidal Limits) to better represent the land/sea interface and create a closer match with WFD Transitional water body boundaries. - Catchment polygons were assigned values representing the SAC and WFD Transitional or Coastal waterbody they flowed into, or could directly affect (i.e. where adjacent) – created using the SAC and WFD Cycle 2 WB layers. Adjustment for Marine SAC nutrient use: - Catchments (polygons) with common combined Waterbody and SAC values were merged. - The Nutrient sensitive Marine SAC freshwater catchments layer still has some areas of flat coastal drainage that needs further data processing e.g. the boundary between the Dee and the Clywd freshwater catchments, and the boundary between Kenfig SAC and Port Talbot (Swansea Bay coastal WB). The Nutrient sensitive Marine SAC freshwater catchments layer has been created in QGIS largely using the PCRaster toolset. Data sources from DataMapWales: - ‘LIDAR data download’ - comprising Welsh Govt LIDAR 2020-2023 - ‘Wales Boundary’ (High Water Mark), - ‘Wales National Marine Plan Boundary’ - (Normal Tidal Limit) - ‘SACs’ - ‘WFD Cycle 2 TraC Waterbodies’. All Open Government Data sources. Data Processing: (QGIS largely using PCRaster toolset) - Native resolution LIDAR Digital Terrain Model (DTM) geotiff data was resampled at 10m x 10m resolution. - DTM converted to PC raster format. - DTM clipped to High Water using Wales (High Water Mark) polygon. - DEM converted to Local Drain Direction (LDD) raster having filled pits in DTM (using ‘LDDcreate’ tool for both tasks) - LDD raster processed (using ‘pit’ tool) to identify drainage outlets to the DTM boundary, creating an ‘outlets’ raster. - LDD and Outlets rasters processed (using ‘catchments’ tool) to create upstream catchments flowing to the outlet points, one for each outlet. Created ‘catchments’ raster. - Converted Catchments raster to vector format. Tidying up and adding data attributes: - The Catchments vector layer was clipped using the National Marine Plan boundary (Normal Tidal Limits) to better represent the land/sea interface and create a closer match with WFD Transitional water body boundaries. - Catchment polygons were assigned values representing the SAC and WFD Transitional or Coastal waterbody they flowed into, or could directly affect (i.e. where adjacent) – created using the SAC and WFD Cycle 2 WB layers. Adjustment for Marine SAC nutrient use: - Catchments (polygons) with common combined Waterbody and SAC values were merged. - The Nutrient sensitive Marine SAC freshwater catchments layer still has some areas of flat coastal drainage that needs further data processing e.g. the boundary between the Dee and the Clywd freshwater catchments, and the boundary between Kenfig SAC and Port Talbot (Swansea Bay coastal WB).