Quick Dips

Flood Forecasting

Historic Kemp House may be better warned about heavy floods in the future, thanks to a system installed by the Hydrology Centre and monitored by the DSIR Water Resources Survey.

Kemp House is New Zealand's oldest wooden building. Built at the mouth of the Kerikeri River, the house has been flooded many times over the years. Derek Goring, commercial manager for the Hydrology Centre, recalls one particularly bad flood where staff found the country's oldest Maori Bible floating in a pool of water. In 1981, water rose to the windowsills and the gardens around the former mission house were destroyed.

The Historic Places Trust commissioned the installation of a flood warning system that will give staff a chance to remove items at risk. Sensors upriver at Maungaparerua weir monitor the rainfall and water flow. If more than 20 mm of rain falls in a hour, an alarm signal is transmitted to the DSIR office in Whangarei. If necessary, it will automatically call staff at home, repeating the calls until it gets a response.

Hydrology personnel will then check the various sensors and run a model of water flow patterns to see if there is a danger to Kemp House. This gives them two hour's warning of the water's actual arrival. If the program indicates that flooding is likely, staff at Kemp House are told, and may be advised to pack up the ground floor displays and move them to a drier location.