Communicating flood hazard mapping with the public – is it worth the effort?

N Nitsche, A Osborne, G Christison (Wellington Water)

B Fountain (Porirua City Council)

There are the complex technical challenge of modelling flood hazards that have received a lot of attention from those involved in flood risk management in Aotearoa. The equally important task of communicating the outputs from the
modelling, gaining the trust of the public and imbedding the modelling results in the full spectrum of hazard management approaches, has plenty of opportunity for improvement.

Engaging the community on the outputs of flood hazard modelling programmes is often difficult as it can be highly emotive, especially if there is a recent history of flooding or concern of the impacts on property prices as a result of hazards being included in LIMs. It can also be met with the opposite and equally challenging reaction of apathy.

Wellington Water Ltd has been undertaking a flood hazard modelling program to model every stormwater asset within the urban area of its jurisdiction. The Flood Modelling project aims to improve the city’s resilience to flooding. Good quality
flood hazard information helps civil defense planning and ensures that new developments are in sensible locations, that homes are built at appropriate levels and that effective planning of infrastructure investment is undertaken. From the
start of this programme Wellington Water has sought ways to improve the communication and reception of the modelling outputs, especially with the public. 

Through our successes and failures, we continue to refine our approach. In our experience we have found that there are many benefits to engaging a community on flood hazards and we would encourage more local authorities to be courageous with public engagement.

We have found that community engagement on flood mapping resulted in improved data collection, higher uptake and use of information, and stronger public and political acceptance. It also has become clear that adopting a one-size-fits-all approach to engagement fails to recognise that each community and council is unique and that good engagement requires gaining an understanding of the social dimensions of a community. Successful engagement takes time, effort and the establishment of trust. This was only achieved with the additional support from communication teams to assist the engineers.

The benefits of public engagement are that it utilises local knowledge to create a better understanding of flooding, and that this can lead to increased understanding, preparation and management of flooding and its impacts.

This paper describes the different forms of public engagement that were used by Wellington Water including workshops, digital platforms and even the traditional letter drop. The paper highlights the learnings from the success and failures that we have gathered and seeks to provide guidance to others who are assessing natural hazards in New Zealand.