Storms can have a substantial impact on the coast and can cause erosion, flooding and damage to coastal infrastructure and property. During storms, large waves and elevated water levels at the coast due to low atmospheric pressure and high winds (known as storm surge) can result in considerable change at the coastline.

During a storm, beaches and dunes typically become eroded, and waves and currents move eroded beach sand/gravel (sediment) offshore, where an offshore bar is formed. During calmer conditions between storms, that sediment is slowly transported back onshore, building up the beach again.

It is not always that simple though; many other factors influence storm impacts on New Zealand’s coast, such as tidal stage, sediment type, wave direction, longshore drift, coastal type (cliffs, rocky shores, sandy beaches, estuaries etc, will all experience storms impacts in different ways). 

The Coast and Ocean Collective Coastal Hub published wave projection (future) and hindcast (past) wave datasets for New Zealand as well as storm surge information. Check out the link below if you want to find out more.