This is the bonus cache for the "Avon Venture: Part X - Burwood to Bower" adventure lab, which takes you along a tidal section of the Avon River as it leaves Burwood and enters New Brighton. There are three bridges on this leg: a new post-quake foot bridge, a modern road bridge where quake damage is still obvious, and a wartime bridge with no obvious quake damage.
For the most part you will be traveling along the north bank of the Avon. There is a shingle path that you can walk/bike on. Take care crossing Wainoni Rd and (if the underpass is flooded) ANZAC drive.