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State Significant Infrastructure


Warragamba Dam Raising

Wollondilly Shire

Current Status: Withdrawn

Warragamba Dam Raising is a project to provide temporary storage capacity for large inflow events into Lake Burragorang to facilitate downstream flood mitigation and includes infrastructure to enable environmental flows.

Attachments & Resources

Early Consultation (2)

Notice of Exhibition (2)

Application (1)


EIS (87)

Response to Submissions (15)

Agency Advice (28)

Amendments (2)


Showing 1 - 20 of 2696 submissions
Natasha Maksimovic
SILVERDALE , New South Wales
I do not support the raising of the Warragamba Dam Wall.
Raising the dam wall is not for extra water supply for Sydney. It’s for development and flood mitigation so that developers can build more houses down stream. By increasing the level of the dam there will be an increased loss of flora and fauna, animal habitats and the significant loss of more of our local Gundungurra heritage.
Kimberley Crofts
BONDI BEACH , New South Wales
My objection is based on two issues. The first is that the raising of the dam walls will put Aboriginal cultural sites at risk and this is no longer something which is acceptable. We must retain and respect Aboriginal heritage. To lose it is not only terrible for the traditional custodians it also robs non-Indigenous people from ever learning more about Aboriginal culture. Taking away this from Aboriginal people is like taking away family. It is country, it is family, it is life. Please respect that.

My second issue is that this project appears to be needed only so that developers can build more housing on a flood plain. Flood plains should not be built upon. They are not only good agricultural land, but we need to let rivers do what they do. We cannot continue to think that human intervention in nature is without risk. We have seen in the last year with the floods in the Hawkesbury that building on flood plains, no matter what supposed mitigations are in place, risks life and housing. It should not be done. Also, building more housing in the west of Sydney where temperatures are likely to rise significantly in the next two decades is risky in the extreme.

Please do not approve this project.
Adele Kimber
SILVERDALE , New South Wales
Dear NSW Government,
I vehemently object to the raising of the dam wall for the following valid reasons:
1. The increased traffic to the area is not supported by current infrastructure (including quality of roads) in the area.
2. The noise created by the increased traffic on the main thoroughfares (Silverdale Rd, Warradale Rd, Marsh Rd) is already at an unacceptable level- people living on the fore mentioned roads are already dealing with living next to free way type traffic noise from 4am and no sound barriers to block the noise. Any increased traffic (particularly by trucks) will absolutely decrease the quality of life for the residents who are already sleep deprived by the increased traffic noise.
3. Any foreseeable disruption to air quality in the area is unacceptable. You already have many vulnerable people living in the area with respiratory conditions- adding to their suffering is insensitive and unjust. Proceeding with a project that will “likely” see a decrease in the air quality of the area is irresponsible and inhumane. You are potentially taking a gamble on the health of the residents of the area and should their be an increase likelihood of respiring illnesses or diseases, you will be likely placed in the position of having to deal with a class action (futuristically speaking). The local public school and day care centres are just metres away from the dam- you will literally be putting the long term health of our children at risk.
4. The cultural significance of the catchment area to the indigenous community is already public knowledge. To disregard the impact that flooding the land will have on the indigenous peoples of the area is reflective of a government decision that is similar to that of the government that justified the assimilation and integration policies implemented in the first half of the 20th century.
5. There are other alternatives to raising the dam wall- building infrastructure that utilises Sydney’s under used desalination plant is a start. Piping the water from the de sal plant to where it is needed is a much more logical and less risky task.

Please, do not proceed with raising the dam wall.

There is no guarantee that there will be enough rain to fill it anyway.


Adele Kimber
Name Withheld
KILLARA , New South Wales
I object to the proposed raising of the Warragamba Dam wall height.

I object to any increased risk of damage to the natural environment (including flora, fauna and natural / geological formations).

I object to any potential risk to indigenous heritage sites and indigenous artefacts. This includes risk of potential damage to the World Heritage listed areas.

I object to the proposed cost of the infrastructure works, as I do not believe the benefits outweigh the costs.

I object to any potential increase in development or density to the floodplains of the Hawkesbury/Nepean region.

I understand the increased dam wall height will not eliminate the flooding risk of the most severe flooding events. If this infrastructure investment will not eliminate flooding risk altogether, it is not worthwhile.
I particularly object to the potential to use the increase flood capacity of Warragamba Dam wall as a potential rationale to increase development within the floodplains.

Whilst I am not a local resident, I am an impacted stakeholder to this decision.

Submissions from any resident of NSW should be given equal weighting. Do not weight the opinions of individuals and corporations with vested interests in increasing development of the floodplains over other taxpayers and residents of NSW / Greater Sydney.

Thank you for the opportunity to make a submission.
Name Withheld
THIRLMERE , New South Wales
The fact that this "plan" made it so far, despite community objection, misleading Environmental impact statements and the potential loss of traditional owners’ cultural sites is a clear indicator of the NSW governments true plans.
Raising the wall is not about flood mitigation. It is to allow developers access to land that is already flood affected, so it can be developed for housing.

- 4700 hectares will be flooded (temporarily?)
- The difference in the “affected” area between the report given to UNESCO and the report pushed by the government are so great, that it is no accidental or accounting error. This is a deliberate attempt to mislead the public. If I was allowed the freedom to speak without recourse, it would be labelled “Blatant corruption”. Unfortunately, I am not , only politicians are allowed to speak (often lies, under the protection of parliamentary privilege).
- This is a deliberate attempt to mislead UNSECO and the public on the governments plans to raise the wall, regardless of independent experts’ advice and opinions.
- The government has handpicked the “stakeholders” responsible for community engagement and environmental reporting (SMEC), as they know that the information provided will not be truth or fact, but a twisted version of reality, best suited to their overall plan.
- The impact of increased flood water levels within the dam is likely to have extensive and significant impacts on listed threatened species and communities and world and national heritage values of the Greater Blue Mountains World Heritage Area.
- Countless indigenous heritage sites lost (SMEC did not even consult with traditional owners who have knowledge on these)
- The community has largely been ignored, in favour of those who stand to make a profit if the wall is raised.

All in the name of developing flood prone land, so developers can run amok.
The NSW Government has stated in its principle document advocating the dam proposal that it plans to allow an additional 134,000 people to reside on western Sydney floodplains after the dam is raised.
There have been numerous inappropriate western-Sydney floodplain developments green-lighted in 2017/18 (the same year legislating to raise the dam was rammed through the NSW Parliament). These include the Penrith Panthers, Penrith Lakes, Marsden Park North and Vineyard development proposals. The SEPP for a number of these areas allows for development below the 1:100 year flood planning level. International best practice dictates that floodplain development should not occur below the 1:500 year level!

Penrith lakes is practically the Nepean River itself! And the government wants to build houses there.

Why is the government pushing for this project so hard? Is there money to be made at the cost of residents?
Who stands to profit from such a project? Clearly not the people of NSW. The ICAC must investigate all parties involved to provide the community a level of honesty, that so far has been missing.

I do not donate to any political party, nor have I been a member of any party in the past, or present.
I stand for honesty, truth and integrity. The government and the parties it has engaged with in pushing forward with this project, clearly do not.
Name Withheld
EBENEZER , New South Wales
I am totally against this project. My family has lived on the Hawkesbury River since first settlement. Raising the wall will only make the floods bigger and deadlier when the water cannot be contained and the even bigger amounts of water held behind the dam will have to spill. The out of control development that is going on in the Sydney Basin and around the Hawkesbury River has already had a massive impact on the river. I am constantly on the river and have watched it get more and more polluted over the last few years. The water looks putrid sometimes and there is that much rubbish in it that it makes me sick. A lot of people have moved in along the river over recent years and they do what ever they want to the landscape, changing the lay of the land with fill and clearing down vegetation that holds the banks together. In the last two recent floods the impact of this was very noticeable to one who has lived through many floods on the river. The flood was unusual and flooded bigger in some spots that have never had it like that before.
I don't believe the wall is being raised for flood mitigation and think it is all about developing the low lying areas across the Hawkesbury Valley and surrounds. There will be blood on the hands of the decision makers if the ridiculous idea gets passed because there will be the day when the dam cannot hold the huge amounts of water that will have to spill and thousands will die.
Shame on all those that only see dollar signs and have no conscience regarding the desolation of the landscape only to develop great tracks of land to bring the world's hordes here to our once lucky country. Stop before it is too late. Australia is being ruined...
Alexander Taylor
SPRINGWOOD , New South Wales
The proposed raising of the dam wall will flood the Blue Mountains UNESCO World heritage listed national park, damaging wildlife areas and aboriginal heritage sites. I do not support raising the dam wall because if this. Studies of the recent 2021 floods show raising the dam wall will not future flood proof the Hawkesbury Nepean Valley. I urge the government not to but the Blue Mountains UNESCO World heritage stays at risk by pursuing this project for the sake of land developers.
Jenny McLaughlin
KATOOMBA , New South Wales
I do not believe that this project needs to occur, the Nepean river and Warragamba dam are not significantly involved with flooding of the Hawkesbury areas. The main culprit is the Hawkesbury river, intermittently letting water out of the Warragamba dam and keeping the levels down to accommodate extra water when heavy prolonged rain does occur will help prevent its adding to the flooding that the Hawkesbury river is notorious for. The reasons given to raise the wall do not out way the damage done if this goes ahead to the WORLD HERITAGE LISTED BLUE MOUNTAINS NATIONAL PARK AND SIGNIFICANT ABORIGINAL HERITAGE SITES.
Please look very carefully at any decision that will impact greatly the NATIONAL PARK AND ABORIGINAL CULTURAL HERITAGE SITES just for the benefit of the Government with the releasing of more land for residential and commercial benefit that sit in these flood prone areas that should not be being developed in the first place. Money and greed should not be more important than nature and cultural heritage.
Harrison Sproule
WARRAGAMBA , New South Wales
Raising the Warragamba Dam wall would be the most colossal waste of tax payer dollars in the communities history, as it will destroy cultural sites, severely damage the environment and have no effect in lessening the severity of floods.

Firstly, Warragamba Dam is part of the Blue Mountains Heritage Site and for good reason. The area is home to hundreds of indigenous sites, sacred to the aboriginals that lived here before us. However raising the dam by 14 meters as proposed would destroy at least 100 of these sites. How can we truly say we live in a modern society that has risen above racism when the State Government proposes plans to knowingly destroy aboriginal culture in a World Heritage Site? How is this different from the intensional mining explosion in Juukan Gorge, WA as part of a mine expansion last year? Such a blunder was heavily criticised by the media for quite some time, Does the NSW Government want to face that same level criticism? There is but one way to avoid such a catastrophe and the ensuing bad press, and that is to abandon this proposal and cancel all plans to raise the Warragamba Dam.

Secondly, raising the wall would irreversibly harm the environment and destroy local ecosystems. Raising the Dam by 14 meters won't just make the wall 14 meters higher. It means the water level across the entire valley will also rise by 14 meters. Thousands of trees would die and be swept away from the rising water, likely to damage the catchment assuming you they aren't chopped down before raising the wall, but that in and of itself also cause irreparable harm to the local landscape. Furthermore all animal life living among those 14 meters above the water level will lose their habitat and certainly die as a result. This includes 50% of the wild population of the Regent Honeyeater, an IUCN red listed, critically endangered species. Actively killing 50% of an endangered, native bird would be to throw away all the progress we have made in order to save said bird from extinction over the last 5 years. This includes the breeding and release program Taronga Zoo initiated years ago. Why would we spend millions of dollars killing the same individuals that we spent millions of dollars protecting and breeding over the past decades? Furthermore while the regent honeyeater will the the most dramatically effected it won't be the only thing effected. Kangaroos, Wombats, Platypuses, Echidnas and wedge tailed eagles all call the Warragamba Dam Catchment home. A severe loss of habitat will effect all of them in s horrific manner. The only solution to such a huge loss of habitat and dramatic impact on local ecosystems is to prevent the Dam from being raised in the first place.

Thirdly, raising the dam will have no effect what so ever on lessening and preventing flood damage and is therefore a complete waste of tax payer dollars. Many media outlets such as channel 7 portray Warragamba Dam opening as the cause of major flooding across suburbs such as Windsor and Richmond. However this is largely inaccurate due to the fact that rain is the cause, not the dams themselves. Furthermore Warragamba Dam only ever spills once areas down stream of it have already flooded as a result of every other dam in the catchment having spilled first. Ask any engineer who worked at Warragamba Dam from the 1960s-1990s, and they'll all use the same analogy: "It's like a bath tub with a hundred taps gushing water into it. It's only once every other tap is on and the bath starts overflowing, that the final and biggest tap turns on. And Warragamba Dam is the biggest tap". So Warragamba Dam doesn't cause flooding, rather it only effects an already flooded area. Therefore Raising it will in no way prevent flooding.

Finally raising the wall will only lead to higher property damages as the Dam cannot prevent or mitigate flooding. Raising the wall by 14-17 meters will only delay the Dams spilling by a few days to 2 weeks at the most. Raising the dam will only serve as an excuse for land developers to build sell property further into flood plains. Putting even more homes at risk during flooding. It's not the dam that floods those houses, it's building those houses on flood plains, that floods them. Following land development trends in the area, this means that 22,000 residents of Windsor and Richmond won't be able to evacuate in time in the event any of flash flooding. Furthermore the Dam was not designed as a mitigation Dam or a retention Dam. It automatically opens once the water reaches a certain level, to let the water flow like a river. Not hold it back. Raising it will not change this. If anything it will completely jeopardise the structural integrity of the dam as it's build like a Pyramid in that no bolts or steel hold it together, rather it's built on an angle so the concrete blocks merely rest atop one another with such a strong relation to its height and weight, raising it threatens to alter this delicate balance. Nonetheless the true solution to the problem is to not build houses in land that we know floods. Hence raising the wall will only incentivise lead the public into a false sense of security, inviting land developers to build further into flood plains putting thousands more at risk.

Overall raising the Warragamba Dam Wall would tantamount to the NSW Government spending millions of tax payer dollars to destroy sacred Indigenous Sites, devastate native critically endangered species in a World Heritage Site and ironically only cause further flood damage down stream of the Dam.
Paul Neurohr
CRANEBROOK , New South Wales
I have heard that the dam will be drained substantially to raise the dam wall
With the rain being unreliable and the time taken for the project to complete I feel it extremely risky to undertake a project putting the water available to millions of residents at risk
Name Withheld
I object to the project on the basis of the environmental impacts from increasing the inundation zone and believe the area of impact has been under estimated. I also consider the proposed offset by purchasing Blue mountains land elsewhere as inadequate and not a valid counter measure to the destruction of world heritage areas. The Blue mountains are incredibly culturally significant and personally important to myself and I do not support comprising the area further.
Name Withheld
SMITHS LAKE , New South Wales
See attachment below
Paul Matthews
TENNYSON , New South Wales


This EIS is a total disaster. The project must not be permitted to proceed. It is clear that the deliberate omission of serious engineering aspects of the proposal means the estimated price of only A$1 Billion is grossly under estimated. This project presents unacceptable risk to the possibility of total dam failure and loss of Sydney’s primary water supply.

If this proposal is even feasible, it is clear that the project works will ultimately exceed 10 years in length and cost at least $20 billion dollars. The omission of this true cost calculation is masking the favorability and feasibility of alternative options.

I can’t believe it’s possible to print so many words, while completely avoiding the primary question which is:


Lets deal with the issues one by one shall we:

1.) There has been NO geological study results because NO proper feasibility study and costing has been conducted.

Referring to Appendix N2:

Nowhere in the EIS is there a geological engineering statement outlining the capability of the surrounding area to withstand the additional forces created around and under the existing dam when the dam capacity is increased. Questions associated with groundwater hydrology on pages 18 and 19 of Appendix N2 have been deliberately blanked out, with this document completely skirting over this critical issue.

Appendix N2 only seems to be concerned with inflows and outflows of the reservoir, not the geological stability of the dam itself or the surrounding rock faces and foundation.

There is no other document provided in the EIS referring to the effect of the project on the water table and rock underneath and immediately surrounding the dam.

2.) There is NO risk assessment in regards to potential dam failure or surrounding geological support failure leading to potentially total devastation of the Sydney basin, potentially with millions of lives lost.

Not one of the EIS documents refers to the risk associated with geological faults or the risk of dam failure and yet, this is the PRIMARY RISK associated with this project.

3.) There is NO tabulation of how the existing dam has performed and moved and continues to move since it was constructed in the 1950s, nor any explanation of how the proposed additions may affect this movement or the ground water penetration underneath the dam foundations.

Warragamba Dam has moved and continued to move and leak since its earliest days of construction. I would expect as a bare minimum, any EIS would tabulate all movements and leaks suffered by the dam in it’s life span so far and detail how these have been handled, drawing conclusions as to how the proposed structure is likely to change these.

4.) There is NO explanation of the ongoing survey and maintenance requirements which will be required to sustain the modified structure and surrounding rock faces.

5.) There is NO explanation as to the geological risk of the dam becoming undermined as a result of “gravity dam rotation effect”:

“Gravity Dam Rotation” (refer attached figure) takes place as a result of a dam being made too steep in reference to its base. The downstream base of the dam acts as a rotation point, around which the dam is somewhat free to rotate upwards when the average position of additional force is applied to the top of the dam by increasing the storage capacity.

The Sydney sandstone upon which Warragamba Dam sits, is porous to water and acts somewhat as a sponge to water under high pressure. The downward pressure imposed on the sandstone by the heavy gravity dam, works to create pressure within the rock which is greater than the pressure of the water, ensuring water cannot enter the sandstone and sustaining the dam foundations, preventing ingress of moisture.

However if Warragamba dam is raised in capacity without the addition of substantial upstream deep foundations and mass, the dam will tend to be “pushed back” when full. This creates a “rotation effect” on the dam whereby more pressure is placed downward at the downstream base causing a reduction of pressure at the upstream base, in effect “tipping the dam over”.

While admittedly it is unlikely the dam would ever be “pushed over”, the action of repeated application and removal of pressure (as the dam is suddenly filled by a flood and then allowed to quickly empty back to supply level) will tend to reduce pressure at the upstream base and allow water to penetrate the existing dam foundations and surrounding rock at each end.

Without adequate engineering treatment such as a drastic increase of the dam mass at the upstream base and increased foundation treatments, the flow of water under the dam through the rock will create cracks and eventually water filled caves through the soft sandstone. Sediment is then washed away into the water table surrounding the dam, eventually finding its way to lower pressure outlets further downstream.

Left to itself, this action will eventually undermine the dam. It will cause dam failure as water attempts to find its way downstream under and around the dam, through the soft sandstone rock fissures that exist. The failure would likely not happen straight away, rather it would happen many decades after the project is complete and after many flood events have systematically placed and then removed rotational pressure on the dam. Each each flood event will cause a small, invisible amount of movement upwards and subsequent damage in the rock foundations under and surrounding the dam.

Once the damage is discovered it will be too late to do anything about it without draining the reservoir completely. If the damage remains hidden and undetected, total dam failure will become possible. This would likely happen at the worst possible time i.e. during a record flood event when the water table below the dam is already high and the downstream communities and catchments are already flooded and saturated.

The only way the Warragamba dam can be sufficiently extended and reinforced at its upstream base will be to completely drain the reservoir and provide a bypass tunnel around the dam for the Warragamba River – as was originally carried out for the initial construction of the dam in the 1950s. The cost of this activity, both in dollar terms and in terms of the loss of Sydney’s water supply for several years, would be immense.

6.) There is NO worldwide precedent for creation of a flood mitigation dam on top of an existing working water supply dam for which foundations have already been completed many decades beforehand.

I would expect an EIS to at least provide a section detailing similar projects overseas, the risks created and how these risks were controlled. The section “Environmental risk assessment procedure” doesn’t even mention the engineering and geological risks associated with raising the dam wall at all! Are we to assume this means these risks aren’t even going to be included in the procedure?

7.) There is NO explanation of how existing dam foundations will be changed by addition of new dam mass on the top and downstream side of the dam.

Indeed the “Project Description” document merely suggests the new work is to be literally “plonked” on top of the existing dam like a jacket (on the downstream side only) with no changes or improvements to the existing foundations or upstream face of the dam.

8.) There is NO evident explanation of how Sydney’s principal water supply will be protected during construction and most importantly how the construction may behave or ow risks may be controlled in the event that an extreme weather event takes place during construction.

9.) There is NO adequate explanation and costing of the practical alternatives, especially provision of sufficient flood escape routes and widening / altering course of Hawkesbury River at Sackville.

The grossly underestimated cost of the Warragamba Dam Wall Raising project masks the effectiveness and worthiness of alternative community based projects which will more effectively mitigate flood risk.

Executive Summary

This EIS is a totally inadequate attempt to justify a project which is impractical when total cost is compared with alternatives, both short and long term. The EIS does not address significant risk associated with the project, in particular risk of long term possible geological failure of the dam and / or surrounding rock faces and subterranean fissures leading to potential severe disaster of a total dam failure.

This project MUST NOT be allowed to proceed.

Paul Matthews
391 Tennyson Road
Tennyson NSW 2754
Hawkesbury LGA
Name Withheld
UNSW , New South Wales
I strongly object to this project.
The extensive destruction of world heritage wilderness along with the negligible benefits provided mean that this proposal should never even have been made in the first place.
Elizabeth Sheppard
To Whom it May Concern

Please find attached below, my Submission to the Warragamba Dam Wall Raising public consultation.

Yours sincerely,
Elizabeth Sheppard
Australian National University, Canberra ACT
Steven Broussos
GREENACRE , New South Wales
This project is needed to help mitigate both droughts and floods. If it doesn't mitigate, it would be less useful
Mike Cottee
FAIRLIGHT , New South Wales
World Heritage sites should be sacrosanct. Once such treasures are harmed, we diminish our legacy for future generations.
Tony Hughes
LOWER PORTLAND , New South Wales
Please go ahead with this essential project. The damage, misery and huge financial cost of floods in the Sydney basin can be mitigated with this important project and government is negligent if it does not urgently act and raise the dam wall. We never want to see floods at the level of 2021 again.
Dennis Ashton
THIRLMERE , New South Wales
The EIS appears to be bias towards the project instead of being objective.
Name Withheld
MOUNT HELENA , Western Australia
I strongly oppose the proposal to raise Warragamba Dam due to the project’s unacceptable potential impacts on the environment including to the Blue Mountains World Heritage Area and threatened species.
The draft EIS concludes that the project poses potential significant impacts to contemporary breeding habitat for the Regent Honeyeater that “cannot be avoided or minimised.”
The Regent Honeyeater is listed as Critically Endangered at both a state and federal level, with as few as 350 individuals remaining in the wild. 
Modelling by BirdLife Australia suggested that up to 50% of contemporary Regent Honeyeater foraging and breeding habitat was burnt in the 2019/20 bushfires. Protecting remaining unburnt breeding habitat is of the highest conservation priority.
There are only a handful of contemporary breeding sites for Regent Honeyeater and during the assessment of the project a total of twenty one (21) Regent Honeyeaters, including active nests, were recorded within the impact area.
Any breeding habitat is considered habitat critical for survival of the species under the National Recovery Plan for Regent Honeyeater and it states “It is essential that the highest level of protection is provided to these areas and that enhancement and protection measures target these productive sites”.
The destruction or degradation of a contemporary breeding site for Regent Honeyeaters would have dire consequences for the species as a whole.
The destruction and degradation of breeding habitat for Regent Honeyeaters is incongruous with the time and money that the Federal and NSW Governments have invested into the recovery program, including the Regent Honeyeater Captive Breeding and Release program.
It is unacceptable and inconsistent with the National Recovery Plan for any avoidable loss or degradation of breeding habitat to occur.
I strongly oppose the Project’s offset strategy for the Regent Honeyeater.
Offsets are rarely an appropriate response to proposed biodiversity loss and especially for critical habitat for the survival of a species, in this case breeding habitat for the Critically Endangered Regent Honeyeater.
There is no evidence that breeding habitat for Regent Honeyeaters can be successfully offset and any offsets would be unlikely to provide direct benefits for both the local affected population and the species.


Project Details

Application Number
Assessment Type
State Significant Infrastructure
Development Type
Water storage or treatment facilities
Local Government Areas
Wollondilly Shire

Contact Planner

Nick Hearfield