Identification, prioritization and mitigation - A three step process for stormwater quality management
In this paper, we present the application of the system on Addington Brook catchment in Christchurch. Addington Brook is a stormwater-influenced brook that headwaters near Blenheim Road, west of Matipo Street, in western Christchurch and joins the Avon River/Ōtākaro near the Christchurch Hospital. Instream surface water quality monitoring has shown elevated heavy metal concentrations in the brook near its confluence with the Avon River/Ōtākaro and it is thought to be a major contributor of the contaminants into the Avon River/Ōtākaro system and downstream estuary. Stormwater runoff from impervious surfaces in the catchment, such as roofs, roads and carparks, is one of the key sources of heavy metals and sediment into the brook. There is limited treatment of the runoff prior to it entering the brook. The application of the system on Addington Brook catchment was done in close collaboration with Environment Canterbury. Total Suspended Solids (TSS), Zinc, and Copper were selected as the contaminants of interest in this catchment.