Clarrie Hall Dam Raising

I am hopeful that later iterations of the planning will also focus on the recreational facilities to be provided with public access to the dam including the move in NSW to allow swimming in these water supply dams as well as boating sailing etc - in the uk I used to sail on many London reservoirs with club facilities supporting these activities - also a substantial increase in walking and mountain bike trails around the dam at a small cost would help with the downside of no longer having access to Mount Warning for both locals and visitors alike, which will also support the rural economy in the small village of Uki Thanks

Maintaining public access for kayaking and walking is important for the community. There is to be a boat ramp which indicates possible launching place for kayaks. A flat area for small kayaking groups , preferably grassed as fibreglass kayaks are easily damaged on hard surfaces plus a place close to the water to park to assist with getting kayaks to the water would encourage more of this heathly activity. The removal of mature trees that will be flooded will lessen possible future boating hazards and maintain the ascetic of the embankment area.

The fire trails along the dam are good for shaded walking and will be mostly above the water level. Access to walking around the dam could be expanded.

In the first instance I and my farming partners are seriously concerned that by raising the height of the wall it will place huge pressure on the wall and weaken the integrity of the wall. It would be catastrophic if the dam burst.
Tweed Shire Council already owns land in the Byrrill Creek catchment, specifically for the purpose of constructing a dam and it makes much greater sense to build a new dam there. There has been a significant amount of money spent by TSC in buying more land in the Clarrie Hall dam catchment and this money would probably have already paid for a new Byrrill Creek dam. The bonus would be that it definitely would help in mitigating flooding to some extent in the future - even though neither dam has been specifically planned for that purpose.
But my/our main concern is safety. And in all the planning reports there is nowhere a 100% guarantee that it could not fail.

I strongly object to the project as destroying more habitat to supposedly catch more water in the midst of the current climate conditions is very outdated. We have seen the impact of this at other dam sites. We need modern water saving strategies to face the future not this outdated practice. The only certainty in Australia are droughts and a 2019 study showed that far from conserving water to be used during times of drought, new dams actually increase the risk of drought.
We need to better manage our water supply and utilise the knowledge and expertise of engineers and those experienced in water planning and management not by biased decisions.

I fully support this project as a guaranteed water supply is the core of our existence and life in the Tweed valley. Tweed Shire Council is to be commended for the years of planning and foresight invested in the project to raise Clarrie Hall Dam. The ever-increasing climatic changes add a sense of urgency in completing this project.

Tweed Shire Council purchased land for a 2nd dam at Byrill Creek NSW. This site should be used to upgrade the water supply for the Tweed Valley. The subject land is zoned for future water supply under Tweed LEP. To raise the dam wall the current water supply will be impacted during construction. There are no valid reasons to not use the Byrill Creek site. Numerous studies and reports recommended the site and past council purchased the site based on expert reports to ensure the Tweeds future water supply.

Raising the dam wall will necessitate landscaping around the new water level perimeter, especially at the Crams Farm end. I suggest that such landscaping should incorporate the Botanic Garden that Council has been planning since 1996. The benefits of the Botanic Garden at this site include:
• public amenity (expanding on the existing leisure facilities with bike and walking tracks;
• education - field trips for schools and horticultural colleges, as well as workshops and guided tours for the general public;
• social cohesion created by volunteering opportunities;
• promoting mental and physical wellbeing and other therapeutic benefits;
• showcasing the unique flora of the Tweed caldera (especially important since the Mt Warning track has been closed);
• conservation of rare and endangered species;
• providing wildlife habitat;
• tourism - the Tweed is a magnate for ecotourism and the Shire already supports many ecotourism enterprises.
The two main obstacles preventing progression of the Botanic Garden project are finding a suitable site; and money. The site at the Crams Farm end of the dam would be ideal because
• the topography is gentle
• Council has purchased most of the farms around the area which are weed free with good soil and abundant water
• the equipment and workers contracted to carry out the dam landscaping could be employed for minimal extra outlay to expand the infrastructure needed to establish the Botanic Garden.
Let’s get two major projects for the price of one and keep ratepayers and government happy with an outcome that is a winning solution for everyone.

Clarrie Hall dam provides the back up water supply for Bray Park Water Treatment facility. Currently the community demand for potable water is about 10,000 ML per year. Coincidently the sewerage facilities in the Tweed are discharging about the same volume of treated sewerage into local estuaries, creeks and sand dunes. Only 6 % of the treated sewerage effluent is reused by the community, primarily in local golf courses, parks and sports fields.
The flooding of this new area will impact both the flora and fauna currently living in these areas. 1 critically endangered, 3 endangered and 8 vulnerable animal species will be affected, koalas amongst them. 2 critically endangered, 5 endangered and 7 vulnerable plant species will also be affected.
There is very little discussion and work done around finding alternatives to reduce potable water by reuse and treatment of sewerage effluent. No 'polishing' wetlands that receive treated sewerage effluent above the catchment areas? Ballina Shire has announced the plumbing of grey water for toilets and gardens for new housing in the Lennox Head area. There are no such initiatives discussed in this EIS. Options are discarded as expensive, difficult and without community support. If we are going to future proof our communities from the affects of climate change we need a paradigm shift in the treatment and reuse of sewerage effluent. I strongly disagree that these options are too difficult and not palatable to the community.

Clarrie Hall dam provides the back up water supply for Bray Park Water Treatment facility. Currently the community demand for potable water is about 10,000 ML per year. Coincidently the sewerage facilities in the Tweed are discharging about the same volume of treated sewerage into local estuaries, creeks and sand dunes. Only 6 % of the treated sewerage effluent is reused by the community, primarily in local golf courses, parks and sports fields.
The flooding of this new area will impact both the flora and fauna currently living in these areas. 1 critically endangered, 3 endangered and 8 vulnerable animal species will be affected, koalas amongst them. 2 critically endangered, 5 endangered and 7 vulnerable plant species will also be affected.
There is very little discussion and work done around finding alternatives to reduce potable water by reuse and treatment of sewerage effluent. No 'polishing' wetlands that receive treated sewerage effluent above the catchment areas? Ballina Shire has announced the plumbing of grey water for toilets and gardens for new housing in the Lennox Head area. There are no such initiatives discussed in this EIS. Options are discarded as expensive, difficult and without community support. If we are going to future proof our communities from the affects of climate change we need a paradigm shift in the treatment and reuse of sewerage effluent. I strongly disagree that these options are too difficult and not palatable to the community.

Clarrie Hall dam provides the back up water supply for Bray Park Water Treatment facility. Currently the community demand for potable water is about 10,000 ML per year. Coincidently the sewerage facilities in the Tweed are discharging about the same volume of treated sewerage into local estuaries, creeks and sand dunes. Only 6% of the treated sewerage effluent is reused by the community, primarily in local golf courses, parks and sports fields. The flooding of this new area will impact both the flora and fauna currently living in these areas - 1 critically endangered; 3 endangered and 8 vulnerable animal species will be affected, koala amongst them. 2 critically endangered, 5 endangered and 7 vulnerable plant special will also be affected. There is very little discussion and work done around finding alternatives to reduce potable water by reuse and treatment of sewerage effluent. No 'polishing' wetlands that receive treated sewerage effluent above the catchment areas. Ballina Shire has announced the plumbing of grey water for toilets and gardens for new housing in the Lennox Head area. There are no such alternatives discussed in this EIS. Options are discarded as expensive, difficult and without community support. If we are going to future proof our communities from the affects of climate change we need a paradigm shift in the treatment and ruse of sewerage effluent. We strongly disagree that these options are too difficult and not palatable to the community.

As a resident of the Tweed Shire, I regularly enjoy the facilities at Cram’s Farm. I often bring oveeseas visitors to Clarrie Hall Dam and Cram’s Farm. It is a major tourist attraction for the Tweed and I will be very sorry to see the lower section of Cram’s Farm near the boat ramp and pine trees flooded. I understand that we need a reliable water supply for a growing population but feel that we are putting all our eggs in one basket by relying on this one source of water supplies. What happens to the Tweed Valley if a structural fault occurs in this raised dam? What happens if there is a terrorist attack on the dam? What happens if there is a biological issue that compromises the water quality in the dam? Authorities should be looking at total water management throughout the valley rather than looking at one quick fix.

I have some significant concerns regarding the Tweed Shire Councils (TSC) proposal to raise Clarrie Hall Dam (CHD). I have bought these concerns to the attention of Council officers who were dismissive of my safety concerns (I have worked for 50 years as a Civil Engineer all over the world including on dam projects but now retired).

During the “Community Consultation Sessions” TSC staff appeared not to have read very much of this EIS document and could not answer questions in regard to this EIS.

Furthermore, it would seem TSC and Kellogg Brown & Root Pty Ltd (KBR) are totally dismissed the alternative Byrrell Creek Dam (BCD) proposal which those constructing the dam would consider far less risky and would provide the Shire with many advantages including no interference with shire water supplies during the construction phase, use of land already owned TSC, a second geographical water supply source, improved environmental flow certainty, better adaptability to climate change, less impact on endangered flora and fauna, and on Aboriginal Heritage sites, .

I am writing to you in the hope that the concerns, outlined below, will be taken seriously and addressed at State Government level. I have requested that my name and all personal information be kept confidential and not published as TSC have a reputation for not appreciating criticism or views contrary to their own.

My major concerns with the 2024 EIS are below:

1. Safety Concerns
a. Safety of the dam as a whole using the construction method proposed by Tweed Shire Council (TSC) and adopted by Kellogg Brown & Root Pty Ltd (KBR), as there is a real chance of catastrophic failure of Clarrie Hall Dam (CHD) wall. In the EIS Scoping Report - Appendix B – Figure 8 – Option 2 Spillway and Training Wall Long Sections – Rev 0 – All new works shown are subject to being washed away for the duration of their construction and is very likely to endanger the entire dam. This construction work and associated risks will last for many months.

b. The EIS Appendix - P Noise and Vibration Assessment, ignores the effects of vibration from the quarry and spillway blasting and large rock compaction equipment on the integrity of 45 year old, 300 mm thick concrete liner on the upstream face of the existing dam or on settlement of the rock in the existing dam , which has only settled only 95 mm in 45 years whereas Blowering Dam in southern NSW had settlement of around 2 metres in a similar time span.


2. Document Conflicts and Ommissions

a. Cost of Project according to TSC, was $100m in February 2024. On Pages 41 and 42 of Section 10. Cost Estimate and Cost Risk Assessment, of the Scoping Report of the EIS, it is stated as between $44m to $55. It appears unlikely any flood risk mitigation and temporary work costs are considered in either costing. Note CHD is a “Brown Field Site” whereas BCD is a “Greenfield Site” and the risk of cost blowouts would be significantly higher with CHD.

b. The EIS Appendix P - Noise and Vibration Assessment considers the quarry and new spillway blasting and construction vibration relating only to surrounding countryside and dwellings. While this is important, the EIS omits to consider the effects of blasting and wall compaction vibration in close proximity to the 45 year old, concrete waterproofing facing on the existing dam wall which is only 300 mm thick and may be under “full load”, nor the fact that the existing dam rock fill has settled only 95 mm in 45 years whereas Blowering Dam in Southern New South Wales had settlement of around 2 metres in a similar time span. The chance of vibration damage to CHD should be of considerable concern.

c. The KBR EIS Executive Summary – Page xxii - states “the Byrrill Creek Dam options had been prohibited by the Water Sharing Plan for the Tweed River Area Unregulated and Alluvial Water Sources 2010” (WSPTRAUAWS2010) or the 2023 version of this document (WSPTRAUAWS2023), is an overstatement. As Doon Doon Creek on which CHD sits is also listed in WSPTRAUAWS2010 and WSPTRAUAWS2023, KBR logic would also dictate that raising CHD would also be prohibited.

d. The number Aboriginal Heritage sites has changed significantly from 81 sites which were identified in TSC own Reports in 2017 and 2018 to just 17 sites in Table 6-54 in the EIS – Chapter 6.5 Aboriginal Heritage Page 292. Of the 17 only two are deemed “Partial loss of value”, the rest are totally lost with the project is proceeding regardless. What happened to the rest of the sites?

TSC started commissioning reports around 2007 and there has been numerous reiterations of documents to get to this one that supports their proposal. I request that this EIS and supporting documents not be approved and TSC be directed to immediately commence work for the construction of Byrrill Creek Dam which had previously been determined to be a cheaper option to secure TSC drinking water supply.

Submission Summary
Maladaptation
• The Clarrie Hall Dam Environmental Impact Statement (EIS) identifies significant adverse impacts on biodiversity and cultural heritage.
• The project’s dependence on rainfall increases its vulnerability to climate change, which is maladaptation.
“Aside from wasting time and money, maladaptation is a process through which people become even more vulnerable to climate change “
• Alternative, more climate-resilient options are acknowledged but not prioritised.
Irreversible Biodiversity Impacts
• Destruction of 246 hectares of native vegetation, impacting endangered species and ecological communities.
• Destruction of 8.77 ha of subtropical rainforest.
• Destruction of 160.87 ha of habitat for Koala (100+ AFL football fields)
• Impacted species include Koala habitats, Mitchell’s Rainforest Snail, Native Guava, and Scrub Turpentine, all of which are critically endangered.
• Biodiversity offsetting costs are projected to exceed $50 million, potentially representing 15% of the project’s total development cost.
Destruction of Aboriginal Heritage
• Raising the dam would damage significant cultural heritage sites, including rock shelters, scarred trees, and artefact locations.
• Aboriginal communities value all assessed heritage sites and express objections despite some agreed mitigation measures.
• The project fails to obtain free, prior, and informed consent, a standard set by the United Nations.
Vulnerability to Climate Change
• The EIS identified there is a strategic need for the project due to population growth and unpredictable water supply due to climate change.
• The project’s dependence on rainfall makes it vulnerable, as climate projections indicate reduced rainfall and increased evaporation.
• Alternative, rain-independent solutions were suggested but were not prioritised, conflicting with the project’s stated goal of climate resilience.

Alternatives Considered
• Alternative solutions, like reuse and desalination, were found to be more sustainable and less damaging than raising the dam.
• Recommendations included exploring water links with the Gold Coast and adopting an integrated water management approach.
• The Council’s focus remains on raising the dam, despite recommendations and emerging data on more viable options.
• Alternatives have not been considered since the 6-fold increase in the cost estimates from $50m to $300m.

I have read the EIS on the raising of the Clarrie Hall dam, not claiming deep understanding of the issues addressed. Amongst the options discarded, deemed expensive and not socially acceptable was indirect potable reuse. This was in2009. We have moved on from this and the world has changed. My opinion is that there is now a better community acceptance of the notion of recycled water and an awareness of the problems of waste water discharge. New technologies allow WWTPs to discharge water of higher quality than water in the target reservoir. Stantec's review was restricted to the three options (dam/ Desal/ SEQ link) and ought to have included all options considered in the 2009 study. Changing community attitudes to potable water and wastewater discharge have changed and could have affected their affirmation that raising the Clarrie Hall dam is our best option to secure the future water supply to Tweed residents. Geoffrey Tomkins

I believe the project is not in the best interests of the region.
A better alternative would be to upgrade the sewage treatment plants and pipe the treated water back into the existing dam catchment.
Several countries already allow treated wastewater reuse for drinking water. According to the 2017 WHO and US EPA census, the states reusing treated wastewater for drinking water production and distribution are Australia, California, Texas, Singapore, Namibia, South Africa, Kuwait, Belgium and the United Kingdom.

The raising of Clarrie Hall Dam in itself seems problematic. It’s an old dam and raising the wall as intended, could fail especially during very high rainfall events (like the 2022 flood) with catastrophic impact downstream. The current proposal seems to not take this into account. Wasting money on EIS on an old dam seems pointless when a new dam could be built as intended at the Byrrill Creek site which is already owned by the Tweed ShireCouncil.
Byrrill Creek was paid for by us ratepayers as a proposed second water catchment dam. It should be therefore used as a dam site as originally intended. This would give Tweed Shire two separate water catchments which with climate change this should be adopted as the much more sensible option.
I want my name withheld as TSC have a history of punitive action against those who disagree with them.

Dear Sir/Madam,

I recently attended the community information session held by Tweed Shire Council at Kingscliff Bowls Club regarding the Environmental Impact Assessment (EIA) related to the proposed raising of Clarrie Hall Dam. Based on the scale and importance of this project, I had anticipated a more comprehensive and informative session. Unfortunately, the session fell short in providing the level of detail and clarity expected from a project of this magnitude.

While several display boards with images and information posters were present, a few copies of binders on a table and staff were available to answer questions, there was no formal presentation or verbal outline that could guide community members through the EIA, project objectives, rationale, cost comparisons, and potential alternatives. As a layperson, I found the session lacked sufficient structure and direction to ensure the community was adequately informed about the project and its potential impacts. At the very least, an overview of the project, including the reasoning for the preferred option, a cost comparison with alternatives, and a discussion of the environmental considerations, would have been valuable.

During the session, I had the opportunity to pose questions to Council staff. While some questions were answered, others could not be addressed, and at times, staff struggled to locate specific information in the EIS documents. For example, I inquired about the potential use of desalination as an alternative to raising the dam, suggesting it could have a smaller environmental footprint. The response I received was, "Where would you put it?" While I understand that practical considerations are important, I believe it is the responsibility of the Council to provide information and explore viable solutions, not to place the onus on community members to propose alternatives. Furthermore, when I asked if desalination had ever been recommended by independent experts as a viable solution to address water security for the Tweed Shire, I was told that it had not. However, subsequent research revealed that desalination had, in fact, been recommended as the preferred option for securing future water supply in the region. This discrepancy raises concerns about the accuracy and completeness of the information provided to the public.

Leaving the session, I found myself with more questions than answers. I was particularly interested to learn that South East Queensland Water is currently investigating expanding the Gold Coast Desalination Plant and the construction of a new desalination facility to address the impacts of climate change. This highlights the growing recognition of desalination as a reliable, long-term solution for securing water supplies in regions facing changing climate conditions.

Upon further review of the materials presented by the Council, as well as additional online research, I am concerned that the Council has not provided a comprehensive cost comparison between raising Clarrie Hall Dam and alternative solutions, such as desalination. The technological advancements in desalination and improvements in its efficiency should be considered in any evaluation of long-term water security options for the Tweed Shire.

Additionally, I am deeply concerned about the environmental impacts of this project, particularly in relation to biodiversity and habitat loss. Tweed Shire Council has not provided sufficient information to demonstrate that the necessary land for offsets has been secured or that the biodiversity values required for offsetting have been adequately identified and protected. The mitigation strategy, which may involve financial compensation rather than actual habitat restoration, does not seem to account for the irreplaceable loss of unique and threatened ecosystems that this project will cause. The economic costs associated with this offsetting, which will likely run into the millions of dollars, have not been clearly communicated to the public.

Climate change is also a significant factor that must be considered in the planning of this project. changes in rainfall and higher evaporation rates are likely to lead to less water for streams and rivers in the Northern Rivers, which will have downstream consequences for storages and place pressure on the area’s water resources. Lower flows and higher temperatures may also reduce water quality. For example, low flows, higher temperatures and elevated nutrients create a more favourable environment for potentially harmful algal blooms (CSIRO 2007).”

In conclusion, I believe the rationale for this project, and the evaluation of alternatives, has not been adequately communicated or substantiated. While the EIA has given considerable attention to the engineering and safety aspects of the dam wall raising, it appears to have overlooked the long-term environmental and social costs. The proposed solution will result in significant biodiversity loss, the impacts of which cannot be offset by typical mitigation measures. Furthermore, the argument for water security through this project has not been fully evidenced, and the potential of desalination as a cost-effective, sustainable solution has not been sufficiently explored.

Tweed Shire Council had an opportunity in 2021 to reassess the inadequacies of the original EIS and to explore desalination as an alternative. Guidance was provided at that time to engage with the Queensland Government and Gold Coast City Council regarding the potential augmentation of the Tugun desalination system as an interim solution. The failure to act on this opportunity raises concerns about the Council's commitment to exploring modern, innovative solutions for the region's water security challenges.

I urge the Council to revisit the options for long-term water security, including desalination, and to provide a more thorough, transparent analysis of the potential impacts of this project. Climate change, evolving technological solutions, and the protection of the region's unique biodiversity should be central considerations in shaping the future of water management in the Tweed Shire.

Thank you for considering my concerns. I look forward to a more informed discussion on this critical issue.

This Proposal has been on the drawing board for a number of years and over that time Caldera Environment Centre has advocated for seeking alternatives to losing yet more critical habitat in this World Heritage Shire. We now accept that this a preferred option to another dam proposal, Byrill Ck and so our focus is on the compensatory habitat required as an offset and it be a genuine attempt to replace like for like.

A Submission to the Clarrie Hall Dam Proposal

FROM: Hastings Point Progress Association


Clarrie Hall Dam is the main water supply to the Tweed Shire.

The current proposal suggests that raising the Dam wall will provide a solution to future water needs for the Tweed.

This submission proposes that raising the Dam wall would be an expensive and unnecessary solution.

While acknowledging the work which has gone into the development of this proposal, as Community members we believe there could potentially be other options which should be considered before a final solution is determined.

The reasons why this needs to be re-considered include:

the dependence on rainwater collection as the only method of water containment
the maladapation to climate change
irreversible BIODIVERSITY impacts
Irreversible destruction of heritage sites
destruction of NATIVE vegetation.


It would appear that insufficient consideration has been given to alternatives to raising the dam wall.

For example:
the Waste Water Plant at Hastings Point requires urgent attention as it has been in violation of EPA standards for some years.
A solution being proposed to this Wastewater Plant is being seen as a bandaid solution which is going to neither achieve a workable solution to the management of wastewater or a solution to the increasing population needs of the Tweed.

It would appear that investigating world best practice management of wastewater suggests that a solution that focuses on value-adding via recycling, rather than a resource draining solution, is potentially a far more viable option.

If this alternative solution was to be investigated it would seem that the raising of the wall could become redundant as maintenance and protection of water resources could be met through other means.

This submission requests that alternative best practice solutions are investigated in order to
consider the water resources and needs across the Tweed from a wholistic perspective
that the cumulative impact of raising the dam wall be weighed against the potential vale add of alternative solutions
consider whether this is the best we can do for the Tweed community.

I object to the raising of Clarrie Hall Dam on the following basis:
- The construction period of any dam raising presents risks relating to failure of the dam.
- To undertake construction activities the water storage level must also be lowered, if the time of construction activities corresponds with a period of drought the water supply for the Tweed Shire will be compromised.
- The Council should be pursuing the construction of a new dam at Byrrell Creek to ensure the long-term water supply for the Shire. There are many advantages of the dam at Byrell Creek when compared to the raising of Clarrie Hall dam, including no interference with water supplies during construction and providing second water source for the Shire and it's growing population.