Horizons Regonal Council DISCLAIMER:

Data from environmental monitoring sites throughout the region are telemetered to the Horizons Palmerston North office on a regular basis. Data is acquired from each site at intervals of between 30 minutes and 24 hours depending on the needs of the primary data user.

Realtime and predicted data available on the Horizons web site are provisional data that have not been reviewed or edited in any way. This data may be subject to significant change before being reviewed and archived for subsequent use.

Users are advised to consider carefully the provisional nature of this information.

Forecast River Levels - User Note:

This river level forecast is based on flood forecasting methods which consider the following data

• soil moisture conditions
• actual rainfall within and near the catchment
• flows within the river and its tributaries
• forecast rainfall provided by MetService

Every effort is made to produce a reliable forecast of future river level however, beyond a few hours, the quality of the river level forecast is strongly influenced by the accuracy of the forecast rainfall.

Actual rainfall data is typically input into the models every 30 minutes and MetService provides an update of the forecast rainfall approximately every eight hours. This forecast rainfall is then applied to the river level forecast at the next model run. When the forecast rainfall is accurate, then an accurate river level forecast can be expected. However, the further into the future you are looking, the less accurate the rainfall forecast is likely to be and, hence, less accuracy can be expected from the river forecasting model.

As the model is updated every 30 minutes, users are advised to check regularly for changes in forecast levels. The forecast level can and will change significantly with time as heavy rainfall crosses the catchment and gets included in the model. Significant changes in river level forecasts are also likely when the eight hourly forecast rainfall updates are received from MetService.