The NSW Tweed River Entrance Sand Bypassing Act and the Qld Tweed River Entrance Sand Bypassing Project Agreement Act were passed in 1995. The Acts detail the NSW/QLD agreement for the sand bypassing project.
Summary of Contracts
A Summary of Contracts that outlines the various arrangements for the construction and operation of the sand bypassing system was tabled in the NSW parliament in April 2001.
The permanent sand bypassing system
The sand collection system is the key to the successful operation of this project. It has been designed for efficient operation, low operating costs and low maintenance requirements.
The system comprises of a sand collection jetty with an overall length of 450 metres constructed perpendicular to Letitia Spit beach. A sand trap has been developed under the jetty by the operation of a series of ten submerged jet pumps. The sand trap is maintained as a permanent depression under the sand collection jetty to allow natural processes to feed sand into this trap from the accumulated sand reserve on Letitia Spit and from the natural littoral drift.
The system has been designed to operate with up to four jet pumps working together at the same time. The sand slurry produced is transported through a flume to a slurry pit located on shore.
The jet pumps are run on water drawn from the Tweed River and will be pumped to a high pressure.
A slurry pit receives the sand slurry and concentrates the sand slurry to the required density.
The sand transfer system draws sand from the slurry pit and pump it through a 400 mm steel pipeline under the Tweed River to one of four outlets in northern New South Wales and southern Queensland beaches. Access diagram of Basis of outlet usage (PDF 220kB).
The project is implemented by the NSW Department of Trade & Investment, Crown Lands in conjunction with the Queensland Department of Environment and Science. The Council of the City of Gold Coast makes a financial contribution to the project and the Tweed Shire Council also supports the project.
Scope of works
The general operation activities of the project scope include:
- Retrieval of sand beneath the jetty and mechanical bypassing of this sand to any one of the discharge outlets located at Point Danger (Snapper Rocks East), Snapper Rocks (Snapper Rocks West), Duranbah or Kirra Point.
- Supplementary dredging from the Tweed River entrance and the nearshore areas adjacent to South Head beach and placement in the nearshore areas between Kirra Point and Point Danger to assist in maintaining the navigation channel and to supply additional quantities of sand if required.
- Any maintenance or additional construction activities that may be required from time to time to meet the objectives of the Tweed River Entrance Sand Bypassing Project.
The costs of the project are shared between the New South Wales and Queensland State Governments, and the Council of the City of Gold Coast.
The interstate cost sharing arrangements are set down within the project's legislation; the NSW Tweed River Entrance Sand Bypassing Act and the Queensland Tweed River Entrance Sand Bypassing Project Agreement Act. Cost sharing arrangements between the Queensland State Government and the Council of the City of Gold Coast are set down within the Queensland Tweed River Entrance Sand Bypassing Project Agreement Act. Project costs are shared on the following basis:
|Establishment costs, including development and construction costs are shared||75% NSW State Government||25% shared between Queensland State Government and Council of the City of Gold Coast|
|Operating costs are shared:||50% NSW State Government||50% shared between Queensland State Government and Council of the City of Gold Coast|
The sand bypassing system was designed and built by McConnell Dowell (Australia) and financed by the Australian and New Zealand Banking Group. The operation and maintenance of the system is being carried out by the Tweed River Entrance Sand Bypassing Company (as subsidiary of the McConnell Dowell Corporation), under a long-term contract of about 24 years. Construction of the sand bypassing system commenced in 2000 and became fully operational in May 2001.
The establishment costs of the system are being paid by an initial payment of about $1.9 M and repayments of about $2.9 M p.a. over the first 12 years of operation.
The project's shared expenditure (including establishment repayments) total $106.4 M since 1999/2000. A breakdown of annual contributions is shown below:
1999 to 2004
|Shared project costs (exc GST)||1999—2000||2000—2001||2001—2002||2002—2003||2003—2004||2004—2005|
|NSW share||$2.9 M||$3.5 M||$5.5 M||$6.4 M||$5.3 M||$5.3 M|
|Queensland share||$1.8 M||$2.6 M||$3.8 M||$4.9 M||$3.9 M||$3.9 M|
|Total||$4.7 M||$6.1 M||$9.3 M||$11.3 M||$9.2 M||$9.2 M|
|Shared project costs (exc GST)||2005—2006||2006—2007||2007—2008||2008—2009||2009—2010||2010—2011|
|NSW share||$5.5 M||$5.3 M||$4.6 M||$5.6 M||$4.1 M||$4.1 M|
|Queensland share||$4.1 M||$3.9 M||$3.2 M||$4.2 M||$2.7 M||$2.6 M|
|Total||$9.6 M||$9.2 M||$7.8 M||$9.8 M||$6.8 M||$6.7 M|
|Shared project costs (exc GST)||2011—2012||2012—2013||2013—2014||2014—2015||Total|
|NSW share||$4.1 M||$4.2 M||$1.9 M||$2.5 M||$70.8 M|
|Queensland share||$2.6 M||$2.7 M||$1.8 M||$2.2 M||$50.9 M|
|Total||$6.7 M||$6.9 M||$3.7 M||$4.7 M||$121.7 M|
Contract payments to the sand bypassing system operator include payments that vary from month to month related to the amount of sand that is intercepted and delivered by the system required to match the natural coastal sand supply conditions. Project expenditure over the next two to three years is anticipated to require a similar level of funding to that of the last two years to respond to typical sand transport conditions and maintain the navigation channel at the Tweed River entrance. However, sand transport conditions can vary significantly for any particular year and actual project expenditure may reduce or increase, depending on natural supply conditions over each year.
Page last updated/reviewed: 13 Jul 2017