Flood Forecasting Model A First For Canterbury

“Development has involved a lot of work to refine and calibrate the model to allow for the variability in natural systems and provide forecasts of river flows in Canterbury’s variable foothill river catchments.”

The flood forecasting system updates its prediction every hour or so and provides a flow prediction on a rolling basis. The forecast rainfall – which is estimated for points in the Temuka catchment – is provided by the MetService one to two days in advance.

“It is Environment Canterbury’s job to monitor local rivers, make predictions on likely flooding and – in liaison with police, civil defence and district councils – as well as warning famers and communities so they can take action to protect life, property and stock.

“Getting a flood forecast wrong is always a major risk. If a flood is not forecast, or turns out to be significantly worse than forecast, it can have very serious impacts including loss of life and property.

“If we are overly cautious and predict floods that do not occur, however, people may not take future warnings seriously,” said Ken Taylor.

Development of the flood forecasting system has taken six months and has involved river engineers and hydrologists from Environment Canterbury working with technical experts from DHI Group.

“We had specific criteria for a suitable flood forecasting system, and also reviewed the track records of suppliers and looked at the recommendations and experience of other users,” said Ken Taylor.

“We required a continuous real-time system that could be developed and run using Environment Canterbury’s local expertise while tapping into the best of international knowledge.

“The system we are installing has achieved this and will be run on a day-to-day basis by Environment Canterbury staff with ongoing support from DHI Group,” said Ken Taylor.