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  3. WWNP Runoff Attenuation Features 1% AEP

WWNP Runoff Attenuation Features 1% AEP

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

Categories

Use limitation statement

There are no public access constraints to this data. Use of this data is subject to the licence identified.

Attribution statement

© Environment Agency copyright and/or database right 2015. All rights reserved.

Technical information

Update frequency

asNeeded

Lineage

A GIS tool developed by JBA, called JRAFF (JBA Runoff Attenuation Feature Finder) was used to analyse potential for Runoff Attenuation Features. This identifies areas of high flow accumulation from the Risk of Flooding from Surface Water Depth 1 percent annual chance map that could be targeted as opportunities for enhanced temporary storage. OS Terrain 50 (2016) was used to determine gully blocking potential, based on a threshold of > 6 degrees (10%). A constraint layer was applied based on CORINE Land Cover Urban layer (2012), OS Open Map Local – Roads, Rail and Building layers (2016) and OS Open Rivers – Canal layer (2016).

Spatial information

Geographic extent

  • Latitude from: 49.943 to 55.816
  • Longitude from: -6.236 to 2.072
Metadata information

Language

English

Metadata identifier

fc69965f-684f-463d-b7c9-2471a5d49741


Published by

Environment Agency

Contact publisher

Defra Data Services Forum

Dataset reference dates

Creation date

01 September 2017

Revision date

30 May 2024

Publication date

09 January 2017

Period

  • From: 01 September 2017
  • To: 01 January 2030

Search

Data and Supporting Information
Data services and download by area of interestLinkAction
Download data by area of interestN/AOpen link
ArcGIS Online Feature ServiceOpen link
ArcGIS Online Tile ServiceOpen link
WWNP Runoff Attenuation Features 1% AEP WMSCopy linkPreview
WWNP Runoff Attenuation Features 1% AEP WFSCopy linkN/A
OGC API - Features serviceCopy linkOpen link
Full downloads and supporting documentationFormatAction
WWNPRunoffAttenuationFeatures1AEP-FGDB.zipZIPDownload
WWNPRunoffAttenuationFeatures1AEP-GML.zipZIPDownload
WWNPRunoffAttenuationFeatures1AEP-SHP.zipZIPDownload
WWNPRunoffAttenuationFeatures1AEP-TAB.zipZIPDownload