Can you Believe that Model?

As part of the Dunedin City Council’s (DCC) 3 Waters Strategy project, 10 Integrated Catchment Management Plans (ICMPs) were developed to support resource consent applications for discharge of stormwater to the marine environment.

Objectives for stormwater management used in The ICMPs are based on those contained in the DCC 3 Waters Strategic Direction Statement (2010-2060); the over-arching document setting the scene for DCC’s three waters’ management. Issues, options and recommendations from each ICMP are incorporated into a city-wide framework as part of the wider Strategy project.

The development of hydraulic models of the stormwater, water supply, and wastewater systems was an integral part of the scope of works for the 3 Waters Strategy project. The stormwater system modelling relied on a large range of background data, including flow monitoring, tide and rainfall analysis, and climate change assessment.

For DCC, however, the use of reported flooding (customer complaints), anecdotal information, photos, and the knowledge base of DCC staff was essential. The ultimate usefulness of the ICMPs relies on DCC’s team understanding the process and believing the outcomes – in this vein, the client/consultant relationship is vital to achieve the necessary collaboration.

This paper outlines the interpretation process followed by the team for the ICMPs, how the model results were reviewed and translated, and how the client/consultant relationship impacted on the outcomes of the project.