The Turner Centre Stormwater Sub-Catchment Design Project addresses the stormwater challenges posed by a new 10-lot commercial subdivision at 31 Hobson Avenue, Kerikeri. Through the resource consent process, it was discovered that the existing stormwater system downstream was obstructed and at capacity. This report details the project’s objective to model the 1% AEP (1 in 100 years) flood plain and includes findings from a comprehensive drone-based topographical survey. The survey data, integrated with council records, informed the development of a detailed MIKE+ model to assess current overland flows, potential flooding areas, and the stormwater network’s overall condition.
Key findings indicate several areas prone to flooding, such as Ranui Avenue, Charlotte Kemp Drive, Oakridge Drive, and Resolution Road, due to under-capacity catchpits and discharge pipes. Additionally, hazard classifications reveal that high water velocities and depths pose risks to people, vehicles, and buildings. To mitigate these hazards and ensure safety, recommendations include upgrading existing catchpits and pipelines, constructing new catchpits where needed, and considering detention tanks to manage peak flows.
