Christchurch City Council is taking to the skies to get a clearer picture of how parts of the district’s coastline are being changed by storms.

Using a helicopter equipped with specialised radar equipment, the Council has completed an initial survey of the stretch of coast between the Waimakariri River and the southern end of Southshore Spit.

The high-flying work is a starting point for future surveys which will focus on smaller sections of the coast, such as New Brighton Pier, Southshore Spit, around surf clubs, and other locations.

Team Leader Coastal Hazards Adaptation Planning Jane Morgan says the Council is taking a big step forward in gaining a more detailed view of how storm-driven waves and swells affect the coast.

“By monitoring the influence of storms on the beach and dunes, we’ll develop an improved understanding of how the coast responds – specifically, how the beach and dunes erode and recover over time, and the extent to which this happens in different locations.

“This monitoring will help us better understand where the coast is most at risk to erosion and flooding from the sea and, in turn, help to inform management of the dunes, such as plantings and wider restoration efforts, as well as other adaptation options to be considered through future planning.”

The surveying uses Light Detection and Ranging (LiDAR) technology, a highly accurate method which creates detailed surface maps of the landscape made up of hundreds of data points per square metre.

Future surveys will be carried out with a drone and happen before and after coastal storm events to measure their impacts on beaches and dunes.

The Council will work with University of Canterbury coastal science staff and students to forecast storms and to collect data about the environment – such as wind, wave and tidal measurements – as storms happen.

The new monitoring programme has been designed to build on the long-term monitoring programme that Environment Canterbury has had in place for the coast since 1990. Together, they will provide one of the most detailed coastal monitoring data sets in the country.