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WWNP Runoff Attenuation Features 1% AEP

Publisher
Environment Agency
Updated
7 April 2026
Topic
Not set

Summary

This dataset has been produced as part of the Mapping Potential for Working with Natural Processes research project (SC150005). The project created a toolbox of mapped data and methods which enable operational staff in England to identify potential locations for Working with Natural Processes (WWNP). Data has been produced for each intervention covered by the project. The final outputs include the following datasets: • Floodplain Woodland Planting Potential • Riparian Woodland Planting Potential • Wider Catchment Woodland • Floodplain Reconnection Potential • Runoff Attenuation Features 3.3% AEP • Runoff Attenuation Features 1% AEP • Woodland Constraints Runoff Attenuation Features Potential is our best estimate of locations of high flow accumulation across the land surface or in smaller channels, where it may be possible to temporarily store water and attenuate flooding during high flows. The dataset is designed to support signposting of areas where to target enhanced storage. It is based upon the Risk of Flooding from Surface Water datasets and identifies areas of high flow accumulations for the 1% Annual Exceedance Probability surface water maps. The areas of ponding or accumulation are between 100 and 5000 metres squared, and have been tagged where they fall on an area of slope steeper than 6% as gully blocking opportunities. All the potential areas have been constrained so that they are not in urban areas or on roads, rails or canals. The data does not does not provide information on design, which may need to consider issues such as drain-down between flood events. It is important to note that land ownership and change to flood risk have not been considered. Locations identified may have more recent building or land use than available. Further information on the Working with Natural Processes project, including a mapping user guide, can be found in the reports published here: https://www.gov.uk/government/publications/working-with-natural-processes-to-reduce-flood-risk Attribution statement: © Environment Agency copyright and/or database right 2015. All rights reserved.

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Additional information

Source Metadata
XML, HTML
Date added
25 July 2025
Harvest GUID
fc69965f-684f-463d-b7c9-2471a5d49741
Extent (Latitude)
55.816° to 49.943°
Extent (Longitude)
-6.236° to 2.072°
Spatial reference system
http://www.opengis.net/def/crs/EPSG/0/27700
Dataset reference date (creation)
2017-09-01
Dataset reference date (publication)
2017-01-09
Dataset reference date (revision)
2024-05-31
Frequency of update
asNeeded
Access constraints
There are no public access constraints to this data. Use of this data is subject to the licence identified.
Responsible party
Environment Agency (pointOfContact)
ISO 19139 resource type
dataset
Metadata language
eng