Purling Brook Green Bridge Concept, Springbrook

Springbrook Road links the homes and school north of Forestry Road with the community centre and Rural Fire Service at Carricks Road, and school children, residents and volunteers walk it. The City's active transport path along that section stops at Purling Brook, where the road narrows to a 5.5 metre carriageway over culverts that go under water in rain. We were engaged in January 2024 to design the structure that fills that gap.

The crossing is a floodway, so the bridge has to go under water and stay put. That makes flotation a design case for a light composite structure, alongside flood load at the City's nominated levels and velocity. Micromesh decking lets water and debris pass straight through, and the concept carries a 2.0 metre clear path, set out in a 3D model and concept drawings for the City.