River Nar at Pentney
cbec, in conjunction with frog environmental, were contracted by the Norfolk Rivers Trust to design restoration measures for the tidally-influenced end of a chalk stream in north Norfolk.
cbec undertook topographic surveys on 3 km of the river, which formed the input for a 2D hydrodynamic model of the channel and floodplain. Together with ecological survey information, this was used to develop and appraise potential restoration options, from which a preferred option was selected.
Erosion and sediment transport were considered in the options appraisal, particularly given the tidal influence on the site. This provided the foundation for detailed engineering designs, implemented in the construction phase, completed in April 2015.
cbec provided a design supervision role during the construction phase.