]> 2026-04-04T05:18:05+00:00 Case study:Nant Barrog 500 en Approved Natural Resources Wales Coed Cymru Bangor University Woodland Trust Rural Development Plan Sustainable Management Scheme Yes No Yes false No 53.1994927,-3.6161483999999 Jacques Natural Resources Wales Sisson ,, Runoff pathway management,,,, Runoff pathway management 23745 Coed Cymru, Bangor University, Woodland Trust, 41 Nant Barrog.png 2017 2457754.5 In progress In 2012, the city of St Asaph – located on a downstream reach of the Afon Elwy (Map 1) – suffered severe flooding which resulted in a fatality. Natural Resources Wales began an investigation into how traditional hard engineered approaches, such as those proposed for the St Asaph flood alleviation scheme, could be supported by Working with Natural Processes (WWNP) measures. The investigation also looked at how these measures could have multiple ecosystem benefits. Llanfair Talhaiarn is a small village in the Elwy catchment, located at the confluence of Nant Barrog with the main river Elwy. The Nant Barrog is conveyed beneath the main street to the Elwy through the Water Street culvert. In periods of high rainfall the culvert is overwhelmed, resulting in flooding of properties in the village. Natural Resources Wales is reviewing the refurbishment of the culvert. WWNP measures recommended for the Barrog in the Elwy Natural Flood Risk Management and Ecosystem Services Study (2015) were further reviewed at the subcatchment scale. WWNP measures for the Nant Barrog catchment were recommended in the Llanfair Talhaiarn Natural Flood Management Study (2015). A revision of the shortlisted options was further reviewed as part of the Llanfair Talhaiarn project appraisal report (2016) and the cost benefits of the different options were considered. The resulting recommended WWNP measures are listed in Table 1.. Coed Cymru, in partnership with Natural Resources Wales, the Woodland Trust and other organisations, will submit a bid in 2017 to the Welsh Government Rural Development Plan Sustainable Management Scheme for funding to implement the measures recommended in the Llanfair Talhaiarn report. The Water Street culvert has an inlet capacity of 4.2m3s-1. Flooding will occur at a return period of a 1 in 50 year event with a peak flow of 4.8m3s-1. Modelling of 4 WWNP packages showed that, when considered separately, sufficient reductions would occur during the 1 in 50 year event for flow to remain within the channel at the culvert. Nant Barrog nant barrog http://www.therrc.co.uk/sites/default/files/projects/41_nantbarrog.pdf No Nant Barrog nant barrog Flood risk management Habitat and biodiversity Land use management - agriculture Land use management - forestry Water quality 2018-11-08T12:32:14Z 2458431.0223843 2018-11-08T12:44:52Z 2458431.0311574 Nant Barrog