3d1e1ac9-50e3-459d-9b63-096bbbe9dbdf NFM Prioritisation for Small Flood Risk Catchments 2025-02-18 Water and Flood Division vector environment Natural flood management 2011-01-01 2022-12-31 51.35197896200664 53.43869079838804 -5.325203278716758 -2.664544486740756 Other Restrictions en This dataset comprises of a prioritisation method for identifying small catchments, above communities at risk from frequent surface water and small watercourse flooding where Natural Flood Management (NFM) may be a suitable means of reducing flood risk. The dataset can be used to support the identification of areas suitable for NFM alongside other analyses undertaken by a suitably qualified person. The information provided is based on a national scale mapping approach, taking into account largely modelled and open-source data, therefore this mapping should be viewed as indicative rather than specific. Locations identified may have more recent building or land use than available data indicates. It is important to note that land ownership and change to flood risk have not been considered. The principles behind this prioritisation were inform by current academic understanding of where NFM may be most applicable and has sought to use the latest Natural Environment Research Council (NERC) research. NFM has been shown to work at catchment scales up to 10km2 where the community at risk is immediately downstream. The catchments have been delineated using OpenPopGrid, a grid-based estimation of population density and the Flood Risk Assessment Wales (FRAW) surface water flood map to identify small communities at risk from frequent flooding. This dataset comprises of a prioritisation method for identifying small catchments, above communities at risk from frequent surface water and small watercourse flooding where Natural Flood Management (NFM) may be a suitable means of reducing flood risk. The dataset can be used to support the identification of areas suitable for NFM alongside other analyses undertaken by a suitably qualified person. The information provided is based on a national scale mapping approach, taking into account largely modelled and open-source data, therefore this mapping should be viewed as indicative rather than specific. Locations identified may have more recent building or land use than available data indicates. It is important to note that land ownership and change to flood risk have not been considered. The principles behind this prioritisation were inform by current academic understanding of where NFM may be most applicable and has sought to use the latest Natural Environment Research Council (NERC) research. NFM has been shown to work at catchment scales up to 10km2 where the community at risk is immediately downstream. The catchments have been delineated using OpenPopGrid, a grid-based estimation of population density and the Flood Risk Assessment Wales (FRAW) surface water flood map to identify small communities at risk from frequent flooding.  These small catchments above communities at risk from frequent flooding are prioritised based on the percentage area of NFM potential as identified in two mapping sources, the Working with Natural Processes (WwNP) potential area maps and the System Cynorthwyo Cunllunio Adnoddau Naturiol (SCCAN) maps. The potential for the following features was summarised in the prioritisation: Runoff attenuation features (WwNP) Floodplain reconnection potential (WwNP) Riparian Woodland (WwNP) Infiltration improvements on slowly permeable soils (WwNP) Hedgerows (SCCAN) Bog restoration (SCCAN) Habitat change and improvements for increased surface roughness (SCCAN) Agricultural management through the retention of winter stubbles (SCCAN) The catchments have been categorised based on the percentage area of NFM potential of: <10% 10%-25% 25%-50% >50% 2025-02-18 OGC:WFS https://datamap.gov.wales/geoserver/ows OGC WFS: geonode Service OGC:WMS https://datamap.gov.wales/geoserver/ows OGC WMS: geonode Service WWW:DOWNLOAD-1.0-http--download /static/geonode/img/missing_thumb.png?v=f626bcf3 NFM Prioritisation for Small Flood Risk Catchments (Thumbnail Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WMS&request=GetLegendGraphic&format=image/png&WIDTH=20&HEIGHT=20&LAYER=geonode:pmfnfm_small_catchments&STYLE=pmfnfm_small_catchments&version=1.3.0&sld_version=1.1.0&legend_options=fontAntiAliasing:true;fontSize:12;forceLabels:on NFM Prioritisation for Small Flood Risk Catchments (Legend Format) WWW:LINK-1.0-http--link https://datamap.gov.wales/layers/geonode:pmfnfm_small_catchments Web address (URL) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typename=geonode%3Apmfnfm_small_catchments&outputFormat=json&srs=EPSG%3A27700&srsName=EPSG%3A27700 NFM Prioritisation for Small Flood Risk Catchments (GeoJSON Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typename=geonode%3Apmfnfm_small_catchments&outputFormat=excel&srs=EPSG%3A27700 NFM Prioritisation for Small Flood Risk Catchments (Excel Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typename=geonode%3Apmfnfm_small_catchments&outputFormat=csv&srs=EPSG%3A27700 NFM Prioritisation for Small Flood Risk Catchments (CSV Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typename=geonode%3Apmfnfm_small_catchments&outputFormat=text%2Fxml%3B+subtype%3Dgml%2F3.1.1&srs=EPSG%3A27700 NFM Prioritisation for Small Flood Risk Catchments (GML 3.1.1 Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typename=geonode%3Apmfnfm_small_catchments&outputFormat=gml2&srs=EPSG%3A27700 NFM Prioritisation for Small Flood Risk Catchments (GML 2.0 Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typename=geonode%3Apmfnfm_small_catchments&outputFormat=dxf&srs=EPSG%3A27700 NFM Prioritisation for Small Flood Risk Catchments (DXF Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typename=geonode%3Apmfnfm_small_catchments&outputFormat=gpkg&srs=EPSG%3A27700 NFM Prioritisation for Small Flood Risk Catchments (OGC Geopackage Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typename=geonode%3Apmfnfm_small_catchments&outputFormat=SHAPE-ZIP&srs=EPSG%3A27700&format_options=charset%3AUTF-8 NFM Prioritisation for Small Flood Risk Catchments (Zipped Shapefile Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WMS&request=GetMap&layers=geonode%3Apmfnfm_small_catchments&format=image%2Fpng&height=550&width=422&srs=EPSG%3A27700&bbox=179010.0%2C166220.0%2C353860.03125%2C393770.03125 NFM Prioritisation for Small Flood Risk Catchments (PNG Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WMS&request=GetMap&layers=geonode%3Apmfnfm_small_catchments&format=application%2Fpdf&height=550&width=422&srs=EPSG%3A27700&bbox=179010.0%2C166220.0%2C353860.03125%2C393770.03125 NFM Prioritisation for Small Flood Risk Catchments (PDF Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/geoserver/ows?service=WMS&request=GetMap&layers=geonode%3Apmfnfm_small_catchments&format=image%2Fjpeg&height=550&width=422&srs=EPSG%3A27700&bbox=179010.0%2C166220.0%2C353860.03125%2C393770.03125 NFM Prioritisation for Small Flood Risk Catchments (JPEG Format) WWW:DOWNLOAD-1.0-http--download https://datamap.gov.wales/download/5219 NFM Prioritisation for Small Flood Risk Catchments (Original dataset Format) CEOS IDN DIF 9.7