4f4c4942-4343-5764-6473-313631353431 English Natural Resources Wales Maes y Ffynnon Bangor LL57 2DW Wales opendata@cyfoethnaturiolcymru.gov.uk 2026-09-04T13:28:07.354Z NRW 1.0 wel British National Grid (EPSG:27700) Halkyn–Milwr Drainage Adit Network (North East Wales) Halkyn–Milwr Drainage Adit Network (North East Wales) Rhwydwaith Ceuffyrdd Draenio Helygain-Milwr (Gogledd Ddwyrain Cymru) Halkyn–Milwr Drainage Adit Network.lyr 2026-06-09 2026-09-04 NRW_DS161541 http://naturalresources.wales/ This dataset represents the approximate locations of the Halkyn and Milwr drainage adit (tunnel) system beneath North East Wales. The adit network was constructed in the early 20th century to lower the regional water table and facilitate metal mining operations in the area. The dataset supports understanding of groundwater drainage processes across Flintshire, where flows are significantly influenced by the presence of the adit system. The mapped locations provide a general representation of the network to inform hydrological and environmental assessments. Please ensure the information warning in the lineage is read and complied with. This dataset represents the approximate locations of the Halkyn and Milwr drainage adit (tunnel) system beneath North East Wales. The adit network was constructed in the early 20th century to lower the regional water table and facilitate metal mining operations in the area. The dataset supports understanding of groundwater drainage processes across Flintshire, where flows are significantly influenced by the presence of the adit system. The mapped locations provide a general representation of the network to inform hydrological and environmental assessments. Please ensure the information warning in the lineage is read and complied with. 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 Mineral resources GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme drainage hydrogeology NRW Thesaurus 2026-08-27 geonetwork.thesaurus.local.theme.converted_nrw-keywords There are no access restrictions on this data. NRW may release, publish or disseminate it freely. noLimitations © CNC/NRW. Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Open Government Licence English geoscientificInformation Wales (WLS) -3.4967 -2.4007 52.9604 53.3903 2026-05-28 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 This dataset has been compiled incrementally over several years using a combination of historical records, legacy datasets, and internal knowledge sources. In some cases, the original source materials are no longer available or cannot be fully verified. The mapped locations therefore represent an interpreted and generalised alignment of the Halkyn and Milwr adit system rather than a precise survey. Positional accuracy may vary, but the dataset is considered sufficient for providing an indicative representation of the network and supporting internal understanding of groundwater drainage processes in the area. Information warning: the dataset is derived from historical information and should be regarded as a reference source only. Due to the age of the source material and uncertainties in the recorded and mapped locations, the accuracy and completeness of the dataset cannot be guaranteed. It is not suitable for operational use, detailed site-specific analysis, or decision-making without independent verification from the data custodian. This dataset has been compiled incrementally over several years using a combination of historical records, legacy datasets, and internal knowledge sources. In some cases, the original source materials are no longer available or cannot be fully verified. The mapped locations therefore represent an interpreted and generalised alignment of the Halkyn and Milwr adit system rather than a precise survey. Positional accuracy may vary, but the dataset is considered sufficient for providing an indicative representation of the network and supporting internal understanding of groundwater drainage processes in the area. Information warning: the dataset is derived from historical information and should be regarded as a reference source only. Due to the age of the source material and uncertainties in the recorded and mapped locations, the accuracy and completeness of the dataset cannot be guaranteed. It is not suitable for operational use, detailed site-specific analysis, or decision-making without independent verification from the data custodian.