NFM Prioritisation for Larger Flood Risk Catchments

Welsh Government

This dataset comprises of a prioritisation method for identifying larger catchments, above communities at risk from fluvial 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.

This prioritisation has been based on an existing dataset highlighting catchments with a “Demand for Natural Flood Management”. These catchments were derived as part of the System Cynorthwyo Cunllunio Adnoddau Naturiol (SCCAN)  maps created by Natural Resources Wales. 

These larger catchments above communities at risk from fluvial 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%

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Attributes (17)

Attribute name Label Description
fid
wfd_id WFD ID Unique ID for each catchment from WFD /ID unigryw ar gyfer pob dalgylch o WFD
wfd_name WFD Catchment Name WFD Catchment Name / ID unigryw ar gyfer pob dalgylch o WFD
catcharea Catchment area Catchment area in m2 / Dalgylch mewn m2
brarea Area of opportunity for bog restoration Area in m2 of potential bog restoration opportunities / Arwynebedd mewn m2 o gyfleoedd adfer corsydd posibl
brclarea Area of opportunity for bog restoration on common land Area in m2 of potential bog restoration on common land opportunities / Arwynebedd mewn m2 o adfer corsydd posibl ar dir comin
spsarea Area of opportunity for soil infiltration improvements Area in m2 of potential soil infiltration improvement opportunities / Arwynebedd mewn m2 o gyfleoedd gwella ymdreiddiad pridd posibl.
rwarea Area of opportunity for riparian woodland Area in m2 of potential riparian woodland opportunities / Arwynebedd mewn m2 o gyfleoedd coetir torlannol
hrarea Area of opportunity for hedgerows Area in m2 of potential hedgerow opportunities / Arwynebedd mewn m2 o gyfleoedd perthi posibl
hcarea Area of opportunity for habitat change Area in m2 of potential habitat change for surface roughness opportunities / Arwynebedd mewn m2 o newid cynefin posibl ar gyfer cyfleoedd garwedd arwyneb
hiarea Area of opportunity for habitat improvements Area in m2 of potential habitat improvement for surface roughness opportunities / Arwynebedd mewn m2 o welliant cynefinoedd posibl ar gyfer cyfleoedd garwedd arwyneb
wsarea Area of opportunity for winter stubbles Area in m2 of potential for winter stubbles opportunities / Arwynebedd mewn m2 o botensial ar gyfer cyfleoedd sofl gaeaf
froparea Area of opportunity for floodplain reconnection Area in m2 of potential floodplain reconnection opportunities / Ardal mewn m2 o gyfleoedd ailgysylltu gorlifdir posibl
rafarea Area of opportunity for runoff attenuation features Area in m2 of potential runoff attenuation feature opportunities / Arwynebedd mewn m2 o gyfleoedd nodwedd gwanhau dŵr ffo posibl
allnfmarea Sum of all areas of opportunity Sum of the areas in m2 of the potential NFM measures / Swm yr ardaloedd y mesurau NFM posib mewn m2
allnfmper Percentage of catchment area covered by NFM opportunity Percentage of catchment Area covered by potential for NFM measures / Canran y dalgylch a gwmpesir gan botensial ar gyfer mesurau RhLlN
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Type:
Spatial data
Category:
Environment

Environmental resources, protection and conservation. Examples: environmental pollution, waste storage and treatment, environmental impact assessment, monitoring environmental risk, nature reserves, landscape

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Publication date:
Licence:
Open Government Licence for Public Sector Information (OGL)

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Copyright:

None

Keywords:
Natural flood management
Point of contact:
Restrictions
<p>This mapping should be reviewed against the following datasets:&nbsp;</p> <ul> <li>Archaeological sites</li> <li>Historic Environment Features (HEF)</li> <li>Historic Landscape Areas (HLA)</li> <li>Registered Historic Parks and Gardens (RHPG)</li> <li>Scheduled Monument (SM) 50m buffer</li> <li>Scheduled Monument</li> <li>World Heritage Site (WHS)</li> </ul> <p>Bio-physical&nbsp;</p> <ul> <li>Acid Sensitive Catchment</li> <li>Ancient Woodland Inventory</li> <li>Deep Peat and Modified Deep Peat</li> <li>Grassland Fungi</li> <li>Potential Habitat for Fritillary Butterflies over Bracken</li> <li>Potential Habitat for Great Crested Newts</li> <li>Potential Habitat for Open-ground Dependent Birds</li> <li>Priority Habitat &ndash; High Sensitivity</li> <li>Priority Habitat Mosaics &ndash; Investigation Required</li> <li>Red Squirrel Areas</li> <li>Regionally Important Geodiversity Site (RIGS)</li> <li>Sensitive Arable Plants</li> <li>Potential Habitat for Water Voles</li> </ul> <p>Landscape designations&nbsp;</p> <ul> <li>Area of Outstanding Natural Beauty (AONB)</li> <li>Registered Common Land</li> <li>National Park</li> <li>Open Access</li> <li>Site of Special Scientific Interest (SSSI)</li> <li>Site of Special Scientific Interest (SSSI) 100/300m Buffer</li> <li>Upland Special Protection Areas (SPA)</li> <li>Upland Special Protection Areas (SPA) 500m Buffer</li> </ul> <p>Agriculture</p> <ul> <li><a title="Agricultural Land Classification" href="/layers/inspire-wg:wg_predictive_alc2" target="_blank" rel="noopener"><strong><span style="color: #236fa1;">Agricultural Land Classification</span></strong></a></li> </ul>
Purpose

<p>This dataset was developed to aid in the identification of catchments suitable for Natural Flood Management.</p>

Language
English
Temporal Extent
Jan. 1, 2017, midnight - Dec. 31, 2022, midnight
Data Quality
<p>The data has been derived from:&nbsp;</p> <ul> <li>SCCAN Demand for NFM</li> <li>WwNP 1% AEP Runoff Attenuation Features</li> <li>WwNP Floodplain Reconnection</li> <li>WwNP Riparian Planting</li> <li>WwNP Catchment Planting</li> <li>SCCAN Bog Restoration Opportunities</li> <li>SCCAN Surface Roughness Opportunities</li> <li>SCCAN Agricultural Management Opportunities</li> </ul> <p>The user should be directed to the Prioritisation Mapping Technical Report for the methodology used to produce this dataset.</p>
Supplemental Information

<p>Derived data produced 2017 &ndash; 2022.</p>
<p>Prioritisation map &ndash; 2022.<br />&nbsp;</p>
<p>This dataset is one of a suite of products developed a…

Spatial Representation Type
Vector data is used to represent geographic data
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