Avon River Stormwater Quality Treatment - An Innovative GIS Design Approach

The Christchurch City Council Stormwater Management Plan (SMP) for the Avon ?t?karo catchment in Christchurch considers retrofit of stormwater quality treatment devices throughout the highly urbanised catchment of 8,862 ha. The concept design for treatment utilised traditional and innovative GIS approaches and proposes a range of water quality devices and mitigation scenarios.

This paper describes the GIS identification of stormwater quality device retrofit locations which form the basis of the mitigation options. An engineering constraints approach informed a complex GIS analysis across the entire catchment. The analysis extended to sizing and costing the devices within the GIS model for two types of treatment device with the overall goal of informing a benefit-cost analysis. The GIS approach enabled easy modification and validation of the proposed retrofit locations as well as visualisation of potential options for future of stormwater management within the catchment.