Metadata detail: NFM Prioritisation for Larger Flood Risk Catchments with weighting for ecosystem service provision

Title

NFM Prioritisation for Larger Flood Risk Catchments with weighting for ecosyste…

Abstract

This dataset comprises of a prioritisation method, with a weighting towards ecosystem service provision, 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 and may also provide additional environmental benefits. 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:

Floodplain reconnection potential (WwNP)
Wider catchment woodland planting (WwNP)
Bog restoration (and restoration on common land) (SCCAN)
Opportunity to improve habitat condition – High priority (SCCAN)
Opportunity involving habitat change – High priority (SCCAN)
Opportunity for retention of winter stubbles in area at greater risk of flooding (SCCAN)

The following features were given a double weighting for potential ecosystem service provision based on an analysis of the WwNP Evidence Directory:

Riparian Woodland (WwNP)
Infiltration improvements on slowly permeable soils (WwNP)
Hedgerows (SCCAN)
Bog restoration (SCCAN)

The catchments have been categorised based on the percentage area of NFM potential of:

<10%
10%-25%
25%-50%
>50%

Licence

Open Government Licence for Public Sector Information (OGL)

Read more about this licence

Copyright:

None

Publication date

18 February 2025

Type

Spatial data

Keywords

Natural flood management

Category:

Environment

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

Find more data in this category

Regions

Global

Approved

Yes

Published

Yes

Featured

No

Group

Water and Flood Division

Spatial extent

Projection system

EPSG:27700

Extension x0

210759.984375

Extension x1

363870.0

Extension y0

167059.984375

Extension y1

394090.0

Restrictions

This mapping should be reviewed against the following datasets:  Archaeological sites <ul> <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> Bio-physical <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 – High Sensitivity</li> <li>Priority Habitat Mosaics – 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> Landscape designations  <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> Agriculture <ul> <li><a title="Agricultural Land Classification" href="/layers/inspire-wg:wg_predictive_alc2" target="_blank" rel="noopener">Agricultural Land Classification</a></li> </ul>

Purpose

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

Temporal extent

Jan. 1, 2017, midnight - Dec. 31, 2022, midnight

Data quality

The data has been derived from: <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> The user should be directed to the Prioritisation Mapping Technical Report for the methodology used to produce this dataset.

Supplemental information

Derived data produced 2017 – 2022.
Prioritisation map – 2022.
This dataset is one of a suite of products developed as part of th…

Spatial Representation Type

Vector data is used to represent geographic data

Email

floodcoastalrisk@gov.wales

Organisation

Welsh Government

Department

Water and Flood Division

Link online

/layers/geonode:pmfnfm_large_catchments_env_weighting