14/01/2026
GCA were requested to assist the with design of a replacement culvert at their Farnborough Hall Estate. The original culvert comprised a relatively small diameter concrete pipe, which regularly flooded causing scour and wear to the surrounding bank and bridge deck. In addition the concrete pipe provided a smooth base to the watercourse through the culvert which causes extremes of very shallow water and rapid velocities making the culvert difficult to navigate for local wildlife.
GCA undertook an analysis of the upstream catchment and designed a new bridge using oversized box section culverts which were sunk below the surrounding river bed level to maintain a natural stone base through the culvert and avoid scour. The residual above ground section of the culvert was increased significantly to avoid flooding and the culvert abutments were finished with gabions to create a sympathetic and relatively cost effective culvert replacement which provides long term benefits to flooding and fauna.
GCA were also able to provide expert advice through the consent process to resolve any design related concerns and achieve a prompt approval to meet tight project deadlines.
