FAQs

There is a need to augment the Tweed Shire district water supply by 2028. This need is as a result of increasing demand for water due to projected population growth in the area and the increasing uncertainty of water supply yield associated with climate change.

In 2009, Council commissioned a study to look at options to augment the Tweed District water supply (MWH, 2009). This resulted in nine options being considered including raising the existing dam, a new dam on Byrrill Creek, a new dam on the Oxley River, a pipeline link to Rous Water, a pipeline link to South East Queensland (SEQ) water grid, desalination, groundwater supply, indirect potable reuse and direct potable reuse. The three short listed options were: raising Clarrie Hall Dam, a new dam at Byrrill Creek and pipeline to the SEQ water grid.

The options that were closely considered by Council in 2014 were - raising Clarrie Hall Dam, construction of a small dam at Byrrill Creek, construction of a large dam at Byrrill Creek Dam, a staged Byrrill Creek Dam construction, pipeline to the SEQ water grid and pipeline link to city of Gold Coast.

The preferred option of raising Clarrie Hall Dam was supported by a project reference group established in March 2018. This group did a comprehensive review of the Tweed District Water Supply, Demand Management and Drought Management strategies.

Council is undertaking studies into water efficiency and demand management to reduce the per capita consumption of water. To date, Council has reduced the total consumption of water by more than 20 per cent per year while the Shire has grown in population by about two per cent a year. It is increasingly hard to replicate the savings that have already been made. As an example, it may be possible to get a person to reduce the time in the shower from five minutes to three minutes but it is more difficult to have them reduce the time in the shower from three minutes to one minute.

The Environmental Impact Statement (EIS) will assess and recommend measures to manage potential impacts. The studies consider impacts that include cultural heritage, biodiversity, flooding, water quality, hydrology, traffic and road safety, noise, air quality, social and climate change.

Studies show that there will be very minor changes to hydrology and flooding due to the proposal. The detailed studies and modelling completed for the EIS to date shows that there will be minimal changes in downstream hydrology.

There will be no “release” of water from the dam in times of high rainfall. Clarrie Hall Dam is built with an open, un-gated spillway – it’s not built to mitigate against flooding. This is because the dam isn’t in in a suitable location for protecting our towns and villages from flooding – its catchment area takes in just 5.7% of the overall catchment area of the Tweed River and its upstream creeks and rivers. For more details and a video to explain how the dam operates, please go to tweed.nsw.gov.au/clarrie-hall-dam#operations.

Approval under the Environmental Planning and Assessment Act 1979 would be provided by the Minister for Planning and Public Spaces or a delegate. Following this Council can decide whether to proceed with the raising of the dam.

If the NSW government provides approval for the proposal along with the conditions of that approval, elected Councillors of Tweed Shire will make the decision on whether to allocate the funds for the proposal to proceed.

Information is available on the Your Say Tweed site. The community is invited to attend information sessions that will occur on 6 and 7 February 2024. More information to come. 

You can attend to get the information that you need and talk to a member of the project team.

In mid 2024, the EIS will be placed on public exhibition via the Department of Planning, Housing and Infrastructure major projects website. Submissions can be made via the major projects website.  Council will provide links to this site from the Your Say Tweed website. The exhibition, and duration for invitation to make submission will be at least 28 days.  More guidance from the Department of Planning, Housing and Infrastructure is available at https://www.planningportal.nsw.gov.au/major-projects/help/how-guides

Construction is expected to commence in 2026 for the dam to be operational in 2028 The construction sequencing and approach is yet to be finalised with input from construction industry specialists.

The water level may be reduced during the construction of the new spillway and, if this were to occur, the water level would only be lowered to an extent to allow construction over the old spillway.

When the existing spillway was upgraded in 2014, the water level was maintained at or above 93% capacity, which was approximately 1.5 metres below full supply level. There will be an assessment of the risk of a drought during construction prior to finalising the detailed design.

Seventeen properties have been identified as being impacted should the proposal be implemented. To date, Council has either acquired, and/or is negotiating with these properties. In addition, an area of about 1.91 hectares (ha) has been revoked from the Mount Jerusalem National Park.

As part of the project, several studies have been undertaken since 2019, including an Aboriginal cultural heritage assessment (ACHA) in accordance with Heritage NSW guidelines, and subsequent addendum. This involved a field survey of about 87% of the project area, with remaining areas subject to targeted inspections; and archaeological test excavations of numerous potential archaeological deposits. The assessment included extensive consultation and participation of the Tweed Byron Local Aboriginal Land Council and Bundjalung traditional owners. A number of objects and/or sites were identified, including stone artefact scatters, isolated stone artefacts, rock shelters, grinding grooves, restricted cultural sites, potential culturally modified trees, knapping sources, and food processing site. 

Additional activities remain ongoing, including further investigation and conservation opportunities for several identified rockshelters. These are all found around the proposed new full supply level, and are being explored for conservation in situ and/or archaeological recovery prior to inundation with the local Aboriginal participants. Further interrogation of the cultural and intangible values of the proposal, given its proximity to Wollumbin, is also being explored by an anthropologist and key Bundjalung Elders and knowledge-holders. Both of these tasks will be integrated into the ACHA. 

The ACHA will make recommendations about the future management of cultural materials within the project area in discussion with the registered Aboriginal parties for the proposal. These are likely to include the development of an Aboriginal cultural heritage management plan to inform any subsequent protocols and requirements, conservation, and archaeological recovery of sites that may be adversely affected. Heritage interpretation of the findings will also be explored at the site or within the broader Tweed Byron LGA.

The existing McCabes Bridge is approximately 20 metres long and 4 metres wide. The existing bridge would be inundated by the proposed full supply level of the dam. The proposed replacement bridge and realignment of Commissioners Creek Road would include a two-lane reinforced concrete bridge raised approximately 5.5 m above the existing bridge level. This would have three 18 metre spans and a width of 8.4 metres and a total length of 50 metres. The entire realignment of the road with the approaches to the new raised bridge is approximately 1,000 metres.

It is estimated that the capital cost of the proposal is $90 million. This does not include Biodiversity Offset costs as this will be calculated when the biodiversity assessment is completed in early 2024.

A portion of Crams Farm would become inundated at the new full supply level. This would result in the loss of some of the public recreation area and require installation of a new boat ramp and pontoon at the new water level for public use.

Re-establishing public recreation facilities at both the spillway end and Crams Farm end of the reservoir would mitigate operational impacts to access and use of public land. Doon Doon Hall and other buildings on Crams Farm will not be impacted by the new water levels and would remain open and operational following completion of construction.

We’re inviting the community to comment on anything to do with the proposal to raise the dam. Issues and concerns raised will be considered in the EIS. The EIS will look into relevant issues and consider mitigation measures or solutions that can be implemented as part of raising the dam. When the EIS is on exhibition mid this year, everyone will have another opportunity to raise issues.  

We’re working on a catchment management plan for the dam and as part of that, we’re considering low-impact recreational activities such as walking, hiking and bird watching. We need to wait until the environmental impact statement on raising the dam is released and reviewed by the NSW Government because recreational activities near the dam will need to be in keeping with the EIS and any conditions that the State Government attaches to it.

Councillors resolved to raise Clarrie Hall Dam after comparing a raised dam with a new dam at Byrrill Creek. Here is a brief overview of the comparison. 

• Environmental releases: There is an environmental release from Clarrie Hall Dam and if a Byrrill Creek dam were built, there would be a requirement for an environmental release from that dam. This means of total stored water, more would be lost if we had 2 dams. This makes a Byrrill Creek dam less efficient than raising Clarrie Hall Dam, as it would not increase our secure yield as much as raising our existing dam.
• Cost: To provide similar secure-yield outcomes, a dam at Byrrill Creek would be significantly more expensive than raising Clarrie Hall Dam.
• Cultural heritage: Consultation with First Nations peoples has informed Council the area around the location of a Byrrill Creek dam contains items and areas of significant cultural heritage, more so than the area that would be inundated by raising Clarrie Hall Dam.
• Ecology: Ecological studies have informed Council the area around the location of a Byrrill Creek dam contains more areas of ecological significance than the area that would be inundated by raising Clarrie Hall Dam.
• Community consultation: Community consultation in 2010 and more in 2019-20 indicated the community prefers raising Clarrie Hall Dam to augment the Tweed District water supply.