Christchurch City Council has taken to the air to understand how storms have changed our coastlines

Using a helicopter equipped with specialised radar equipment, staff have surveyed the coastline between the Waimakariri River and the southern end of Southshore Spit.

It will provide the starting point for future surveys - which will focus on smaller sections, such as New Brighton Pier, Southshore Spit, and around surf clubs.

Spokesperson Jane Morgan says this monitoring will help them better understand the places most at risk to erosion and flooding.