Gold Coast, QLD
Causes
The Queensland Gold Coast consists of 35 km of coastline, from the NSW border up to the Nerang Inlet. The location relies heavily on tourism and therefore its large, golden stretches of beach.
However, in the 1960's a rock wall was constructed at the entrance to the Tweed river (just south of the QLD border) as a management strategy to stop sand entering the river which was making it hard for boats to enter. This wall prevented the natural northerly flow of sand due to longshore drift, thereby starving the Gold Coast beaches of sand.
As the sand supply was depleted, combined with a series of severe cyclones, in 1967, 8 million cubic metres of sand was eroded from the beaches and threatened the Gold Coast roads, houses and hotels.
Watch this video (at least up to 4.18mins) to learn more about the history of erosion of the Gold Coast beaches.
Tweed River entrance in 1935 prior to breakwater extension
Management
The solution has been threefold. First, a continuous terminal seawall was built the length of the coast and covered with sand and dunes. Second between 1995 and 2000, 3.5 million cubic meters of sand was dredged from the Tweed Bar and placed offshore of the southern Gold Coast beaches. Third, a permanent pumping system was built just south of the training wall, which since 2000 has pumped more than 500 000 m3 of sand each year from New South Wales across the border onto the Gold Coast beaches. In 2007 these beaches were as wide as they have ever been. However, it has all come at a cost in the tens of millions of dollars.
Other Gold Coast coastal erosion management strategies
Artificial reef
60,000 tonnes of rock was placed 270m from the shore at the Gold Coast's Palm Beach. This was to create a buffer that reduces wave energy reaching the beach, lessening erosion.
Beach nourishment
In 2017 over 3 million cubic metres of sand was dredged from the seabed offshore and added to Gold Coast beaches.
Seawall
Seawalls on the Gold Coast are made of large boulders buried under the sand and are used to protect properties and infrastructure.
Sand Pipeline
The pipe will funnel sand from the existing Sand Bypass Jetty at The Spit onto the upper beach along Gold Coast northern beaches including Surfers Paradise.
Mapping activity
On Timelapse - Google Earth Engine find the Tweed River and North Kirra Beach.
Observe the shoaling changes at the river mouth and northward movement of sand (longshore drift).
Watch for changes to the width of the North Kirra Beach over time.
The pipeline project (phase one) was completed in 1999 and sand dredged from the tweed river mouth was used to nourish Kirra Beach. Phase two, the pipeline project commenced in 2000. Compare the width of the beach in 1998 with that of 2008.