Dredging

Dredging Update 2nd August 2019

Tweed Sand Bypassing is now more than half way through the dredging campaign with 89,000 cubic meters of sand being delivered. Of this sand, 30,000 cubic meters has been delivered to Duranbah, 19,000 cubic meters to Tugun / Bilinga and 40,000 to Snapper Rocks East.

The final approval for the Fingal dredge delivery area has now been received. On Monday 5th August, the Albatros will commence delivering 30,000 cubic meters of sand to Fingal. It is estimated that this will take a week to complete.

The Tweed Sand Bypassing app has now been updated with a more detailed dredge delivery map. This shows the three new placement areas, two of which are being used in this current campaign.  More information on the TSB app, and where it can be downloaded, can be found here.

Dredging

Dredging of the Tweed River Entrance has now commenced. Dredging started on the 14th of July 2019, and will take approximately 6-8 weeks. 150,000 cubic metres of sand will be dredged from the Tweed River entrance and delivered offshore of the southern Gold Coast Beaches and Duranbah.

In addition, a new placement area at Tugun/Bilinga will be used, along with possible placement at Fingal. Use of the Fingal dredge delivery location is subject to final approvals and licences being obtained. If sand is delivered to Fingal, it will be a trial, and will be subject to a range of environmental controls and monitoring.

The new delivery areas of Tugun/Bilinga and Fingal were developed to address community concerns regarding the more even distribution of sand. This approach is aligned with the findings of the Ministerial Feasibility Studies which was completed in 2011: more information can be found here.

What is dredging?

Dredging is the process of moving sand from one part of the ocean floor to another. This happens by using a dredge boat, which takes sand from the seafloor, and stores it on-board. The boat then moves to the desired location, and the sand is released, falling to the bottom of the ocean. An image of the Albatros, which is the dredge boat completing the work for Tweed Sand Bypassing, can be seen below.

view1

Why is it happening?

The two objectives of Tweed Sand Bypassing (TSB) are to establish and maintain a safe, navigable entrance to the Tweed River, and restore and maintain the coastal sand drift of the southern Gold Coast beaches.

TSB is made up of both the sand bypassing facility and periodic entrance dredging. It was designed this way. The jetty collects most of the coastal sand drift, but some sand still moves past the jetty and into the Tweed River entrance. This sand builds up over time, requiring periodic dredging.

The sand is removed from the Tweed River entrance and deposited to locations offshore.

Keeping the Tweed River Entrance safe and clear of sand is vital for the commercial and recreational boating community. It allows commercial fishermen access to the ocean to make their living, as well as providing tourism operators, commercial yachts and other recreational water users continued and safe passage.

Moving the sand from the entrance and placing it in strategic locations protects coastal assets, and supports the coastal lifestyle that is an integral part of the region’s identity.

What are the details?

The 2019 dredging campaign will remove approximately 150,000 cubic meters of sand from the Tweed River entrance. The picture below shows a map of where the sand will be placed.  Although there are lots of different areas where sand can be delivered, the exact location is calculated by analysing underwater survey information.

2019 Dredging campaign locations

2019 Dredge placement locations

The following table shows how this sand will be distributed. These volumes are estimates only. Dredging is dependent on favourable weather conditions and the condition of the dredge, and can be delayed at any time without notice.

Estimated Sand Delivery (cubic meters)

Location

54,000

Snapper Rocks East

36,000

Duranbah

30,000

Tugun / Bilinga

30,000 (subject to final approvals)

Fingal

As described above, it’s important to note that the Fingal Placement area is subject to final approvals and licences being obtained. If these are not finalised during the July 2019 dredging campaign, then the 30,000 cubic meters of sand allocated to Fingal will be re-distributed through the other three selected placement areas.

Why is the dredge offshore of Kirra?

The Albatros is unable to remove sand from the Tweed River entrance when there are waves breaking on the bar. This happens during increased south to southeasterly swells and at low tide. When this occurs, due to the orientation of the coastline, Kirra is the safest place for the boat to be, and it may frequently be seen stationed here during the dredging campaign.

How can I stay informed?

You can download the TSB smart phone app and follow us on Instagram. Alternatively, you can contact us at tresbp.projectoffice.group@crownland.nsw.gov.au. Dredging enquiries can also be directed to the TRESBCo Operations Manager on 0408 345 334.

Page last updated/reviewed: 02 Aug 2019