cbec undertook an investigation and provided advice on solutions for stabilising some large trees that were washed into the channel during a winter storm and were deposited on the channel bed upstream of the Abergwyngregyn village, Gwynedd, Wales

Natural Resources Wales advised that the large wood should, if feasible, be retained within the channel to provide ecological enhancement through habitat creation, but also to add roughness to the channel to help slow the flow of flood waters. To advise on the appropriate methods for securing the large wood in place, cbec undertook a topographic survey, sediment sampling and hydraulic modelling of the site.

Following the site surveys and the hydraulic modelling, which determined the total load (both from drag and buoyancy) on the two primary log structures for 100-year flood flows, cbec engaged with experienced restoration contractor Salix to draft a recommendations memo, outlining the best solution for fixing the large wood to the bed of the channel and to protect the left bank from future erosion.

cbec Projects - Abergwyngregyn measure