STREAMLINING MINIMUM FLOOR LEVEL ADVICE DIGITALLY

I. Kholodov (Wellington Water Ltd), T. Nation (Collaborations Ltd)

ABSTRACT

National and world news regularly highlight human tragedies resulting from extreme flood events. A major frustration for professionals working in the field of flood controls is that this is preventable through better planning rules, site selection and building dwellings above flood level.

Wellington Water is committed to the minimisation of future flood damage of new properties. Since 2015, a flood modelling programme with the aim of identifying flood hazards throughout the region has been carried out. A significant challenge is to provide the model results to the public through practical means in addition to currently used LIMS and published District Plan maps.

With flood modelling data coverage expanding, information requests steadily grew to become a torrent requiring more time for response. Initially, there was no consistent procedure for providing flood level advice and assessments of flood risks and floor levels were provided ad hoc. This meant that over a period of 2 to 3 years more than one flood risk assessment for the same property could have been produced with potentially different advice as models progressed from draft to final over those years. Subsequent consistent documentation of the flood risk assessments improved the quality of advice. The challenge introduced was that the additional documentation increased assessment time and responding to land development queries became a full-time commitment for many staff at Wellington Water. To ensure efficiency a change was needed to streamline modelling advice.

Investigation into the queries showed that due to 90% of land development queries only being nonspecific inquires of flood hazard instead of mitigation effect advice, flood summary for each property parcel could be made available on an ArcGIS online App with clear step by step instructions for self-service assessment.

By using this App, land development team has modelling advice at their fingertips, without having to rely on the Modelling Team for every query. In its current form, this App has already significantly reduced workload of many at Wellington Water, allowing staff to work on less tedious and more creative activities. Transition to customer self-service to get property flood reports is still an ambition of many. To facilitate this, the app must allow customers to sample results where a building is proposed by drawing a polygon to sample background flooding data from desired location and generate a report.

This paper describes the various specialized spatial analysis tools that Collaborations Ltd applied and the technical considerations that were used to provide a customer self-service App. The paper highlights the learnings and challenges that were encountered answering the land development queries, and the advantages this App solution provides.

The next step will be, with Council's agreement, to roll this App out for public use. When/If that happens, minimum floor level advice for most proposed developments will be provided online and only large, multi-unit developments will require involvement from Wellington Water staff.