4f4c4942-4343-5764-6473-313231333633 eng dataset Natural Resources Wales (NRW) 0300 065 3000 Maes-y-Ffynnon LL57 2DW enquiries@naturalresourceswales.gov.uk pointOfContact 2023-01-31 Gemini 2.2 urn:ogc:def:crs:EPSG::BNG OGP Working with Natural Processes (WWNP) in Wales: Runoff Attenuation Features 3.3% AEP WWNP Runoff Attenuation Features 3.3% AEP - Wales Nodweddion Arafu Dŵr Ffo 3.3% AEP WWNP - Cymru 2018-03-12 publication 121363 https://naturalresources.wales 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 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 3.3% 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 canal s. Natural Resources Wales (NRW) 0300 065 3000 Maes-y-Ffynnon LL57 2DW enquiries@naturalresourceswales.gov.uk owner Natural Resources Wales (NRW) 0300 065 3000 Maes-y-Ffynnon LL57 2DW enquiries@naturalresourceswales.gov.uk originator notPlanned Geographic Information System Land use GEMET - INSPIRE themes, version 1.0 2023-02-01 publication © CNC/NRW. Some features of this information are based on digital spatial data licensed from the Centre for Ecology & Hydrology © NERC (CEH). Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose. otherRestrictions There are no access restrictions on this data. NRW may release, publish or disseminate it freely. eng environment ISO3166 Countries 2023-02-01 publication Wales (WLS) -5.77774100 -2.60886500 51.24082900 53.51306700 2018-01-01 2018-03-12 Natural Resources Wales (NRW) 0300 065 3000 Maes-y-Ffynnon LL57 2DW enquiries@naturalresourceswales.gov.uk distributor https://datamap.gov.wales/layers/inspire-nrw:NRW_WWWP_RUNOFF_ANTEN_3PC View and Download Data https://datamap.gov.wales/capabilities/layer/506/?access_token=i61nd1X0RwdwAgQrGW0sqAsWxBMiwx&ows_service=wms Web Mapping Service dataset 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 JBA Consulting carried out the contract.