Horizons Regional Council's Rachel Keedwell: Webcams invaluable for flood monitoring

Water monitoring is critical for policy development and for the science that underpins that policy. Photo / Horizons Regional Council

OPINION:

Whether you want to know the water quality for swimming, or what the river flows mean for your farm management, or to just check the web cameras to see where the surf is up, this is all information Horizons Regional Council collects and has freely available on its website.

Our river monitoring network collects extensive information from 82 sites across the region, forming the basis of an early warning system for floods. Many of the monitoring sites send data every half hour to update models on river flow and this is essential for flood predictions and emergency management.

As an example, in the Whanganui River catchment, measurements of rainfall and river flow up the top of the catchment can provide predictions of the peak river flows downstream in Whanganui 12-14 hours before the peak occurring. This gives plenty of time for evacuation and planning for the installation of flood barriers and can ultimately save lives.

Similarly, farmers can use the flood models to assess when to move their stock to higher ground and prevent stock losses due to flooding. Stock losses were significant in the 2004 floods and with the expanded river monitoring network now in place across the region, many farmers rely heavily on the Horizons data for guidance on flood risk.

The collection of these data relies on the telecommunications network. To avoid data outages in an emergency, Horizons has invested in a network of 19 repeater sites that give coverage to about 90 per cent of the region to ensure access to critical data is seldom lost.

Our monitoring data has a much bigger application than just helping with managing emergency flood events. Information is key to decision-making and we have huge amounts of information coming in from our networks monitoring the water quality in lakes, rivers and groundwater. This information is critical for policy development and for the science that underpins that policy.

We need to completely overhaul our freshwater plans and policies and put in place new ones to meet government directives by 2024, and this task would be impossible without the extensive data coming from our monitoring networks. The information also provides the modelling data for determining where future assets such as stopbanks and flood diversion structures can be best placed to protect communities.

Data on rainfall, air quality and soil moisture is also available on the Horizons website, but probably one of the most used features is the webcams. The first webcam in the network was useful for monitoring the lahar situation on Mt Ruapehu in 2007, but with the improvements in technology and increasingly lower costs, the network has expanded to 41 webcams that form a cost-effective way to monitor river conditions, floodgates, and the coastal environment in real time. The cameras provide imagery that can help us understand the environment we are measuring, and are invaluable for emergency management and flood monitoring.

• Rachel Keedwell is chairwoman of Horizons Regional Council.