The St Asaph Flood Alleviation Scheme was the first project awarded under the Natural Resources Framework. The works were commissioned following a history of flooding, most recently in 2012 when floods affected 320 homes and businesses, 70 caravans, community facilities and roads to depths of up to 80cm throughout the city.
We raised existing and constructed new defences along both banks of the River Elwy in St Asaph and to provide a new defence at downstream of the main works. We constructed over 1000m of 4m high flood embankments, using a mixture of imported cohesive fill and site-won cohesive material (tested on site) and construction of over 1000m of flood wall using a variety of disciplines.
Construction of the flood walls included steel reinforced concrete walls clad with a natural limestone and brickwork in keeping with the conservation areas; king post walls infilled with reinforced concrete and clad with natural stone masonry; and sheet pile walls, infilled with concrete and clad with natural stone and brickwork. We also constructed over 1500m of footpath, including 750m of tarmacadam surfaced Sustrans-specification cycle route.
We also constructed a new 26m single span reinforced concrete bridge, which accommodates a 3m wide carriageway and 1.5m footpath.
Natural Resources Wales