Ocean and coastal waves

Ocean waves build and maintain beaches, promote diversity in marine habitats and ecology, and provide recreational amenity for swimmers and surfers.

Ocean waves distribute sand along the coast and onto beaches, where it is continuously recycled between surf zone bars, the beach and dunes.

However, the destructive nature of waves is experienced during East Coast Low (ECL) storms, damaging coastal environments, properties and infrastructure. During ECLs, sand is eroded from beaches and moved offshore into surf zone bars, which break waves farther from the shore and ultimately limit destructive wave energy at the beach.

Following storms, constructive waves replenish beaches by transporting the sand back onshore. Depending on the severity and frequency of storms, full beach recovery may take several months to several years.

Department of Planning, Industry and Environment is working to improve our understanding of coastal wave conditions throughout NSW by measuring and modelling waves as they travel from the ocean to the coast.

Bournda National Park

Bournda National Park Photo: J Spencer/OEH

Garie beach, Royal National Park

Garie Beach, Royal National Park Photo: D Finnegan/OEH

Measuring waves

The Department manages the NSW Coastal Data Network Program. Data is collected at seven offshore locations along the NSW coast by NSW Public Works Manly Hydraulics Laboratory, and is used by scientists, engineers, government agencies, and the public. Long-term wave records are crucial to understanding regional wave climate variability and the likelihood of extreme conditions.

The distinctive underwater topography at each NSW beach influences waves as they approach the coast, and conditions at one beach may be very different from the next, even at the same time. Department scientists deploy Waverider buoys off beaches and rock platforms to measure waves before they break. The research aims to understand why some locations are more impacted by wave processes and coastal hazards than others.

Wave modelling tools

In collaboration with Baird Australia and NSW Public Works Manly Hydraulics Laboratory, we have developed a suite of tools that rapidly transform offshore wave conditions to the NSW coastline. The NSW Nearshore Wave Transformation Tools provide a rapid, efficient and reliable means to calculate and visualise past and future nearshore wave conditions. More than 14,000 nearshore output locations are currently available in 10m and 30m water depth.

Low southerly waves in Sydney map

Toolbox output: Low southerly waves in Sydney

High southerly waves in Sydney map

Toolbox output: High southerly waves in Sydney

The NSW Nearshore Wave Forecast Tool provides nearshore wave conditions over a rolling nine-day period for all NSW beaches, using real-time offshore Waverider buoy measurements and a regional ocean wave forecast model.

The NSW Nearshore Wave Transformation Toolbox is an advanced set of tools that provides coastal professionals with access to over 35 years of nearshore wave conditions along the NSW coast. The toolbox allows users to visualise nearshore wave conditions for locations and time periods of interest, and functionality to generate and export datasets.

The tools transform ocean wave data collected through the NSW Coastal Data Network Program to the coastline. To supplement historical ocean wave measurement data, we also maintain a global-regional ocean wave model.