I am pleased to present this interim report of the Select Committee on the Proposal to Raise the Warragamba Dam Wall.
The March 2021 flood event in the Hawkesbury Nepean Valley highlighted the substantial flood risk in the valley and the importance of flood risk planning and management to limit the impact of flooding on lives and property.
The Warragamba catchment contributed less than 60% of the flows to the March flood, indicating the significant contribution to major flooding in the valley from catchments other than Warragamba and demonstrating some of the limitations of this proposal.
At its peak, the volume of water that flowed over the Warragamba Dam during that event was enough to fill the airspace that would be created by a 14 metre dam wall raising in just two days, demonstrating major upstream impacts would be inevitable should the project proceeded, even in an event assessed as a 1 in 10 to 1 in 20 chance per year event.
In that regard, the focus of the NSW Government should be directed to those flood risk mitigation options that can maximise flood risk mitigation while minimising upstream impacts. The evidence heard by the Committee casts significant doubt over whether raising the Warragamba Dam wall can achieve those objectives.
It is encouraging that this report has unanimous support from both Government and non-government members.
The committee heard from a wide range of stakeholders, including from the insurance industry, the Committee for Sydney, and emergency services experts of the need to more fully consider alternatives for flood mitigation and has recommended a round table be established to begin this work.
The report recommends more consideration of alternatives to a dam wall raising, including lowering the full supply level of the existing dam, improved evacuation routes, and moving people off flood prone land, including consideration of buybacks.
It is unequivocal that the project will have significant, if not devastating, impacts on upstream biodiversity, including on critically endangered species like the Regent Honeyeater and pristine wild rivers like the Kowmung. The 2019/20 fires have only heightened the risks of impacts from temporary inundation that the dam wall raising will cause. It is deeply concerning that additional field work had not been done to update environment assessments to take into account fire impacts and the committee has recommended this occur.
The committee was also concerned about the secrecy of the Government around questions regarding the biodiversity assessment process and proposed offsets. The committee has recommended that all biodiversity impacts from temporary inundation be assessed for the purposes of determining required biodiversity offsets.
Despite this, it is inconceivable to me, and I suspect many members of the public, how critically endangered species, World Heritage listed areas and wild rivers can be suitably offset by a credit trading system.
Importantly the report recognises that should the project not be able to maintain or improve the current and future integrity of the Greater Blue Mountains World Heritage Area, the Government should pursue alternatives. This is the clear expectation of the published Strategic Plan for the World Heritage Area.
The evidence seen and heard by the committee, including from State and Commonwealth agencies, suggests the dam wall raising will have significant negative impacts on the integrity of the World Heritage Area and its values.
The inquiry also received significant evidence about the impact the proposal will have on Aboriginal Cultural Heritage, including on sites that are part of the creation story of the Gundungurra People. Aboriginal stakeholders expressed frustration and even anger about the adequacy of the Aboriginal Cultural Heritage Assessment process including site assessments.
The committee recommends that the project not proceed without free, prior and informed consent by Registered Aboriginal Parties.
The inquiry was established to inquire into a wide range of issues relating to the NSW Government’s Proposal to Raise the Warragamba Dam Wall as outlined in the Committee’s Terms of Reference.
During the conduct of initial hearings it became clear that Government witnesses intended to deflect many of the questions asked by indicating that questions would be addressed in the final Environmental Impact Statement (EIS) when published.
When the inquiry was established on the 20th of June 2019, it was understood that the EIS was close to completion at that time. The NSW Government placed the final EIS on public exhibition on 29 September 2021, the day before this committee was due to meet to consider this interim report.
The committee had decided to complete an interim report following the substantial leaks of State and Federal agency criticisms of aspects of the draft EIS, including inadequacies in the ‘on the ground’ field work to assess the impacts that raising the dam wall would have on environmental, world heritage and Aboriginal cultural heritage values as well as post 2019/20 fire impacts.
The March 2021 flood event in the Hawkesbury Nepean was considered by the committee as a case study to better understand the flood risks in the valley as well as opportunities and limitations of the proposal.
This report largely deals with those official agency criticisms and the flood mitigation capacity of the proposal with regard to the March 2021 flood.
I thank those who contributed to the hearings following months of flood clean-up and assisting impacted residents and acknowledge the impact the floods had on many residents and businesses.
The other terms of reference and a detailed consideration of the final EIS will be dealt with in a final report.
On behalf of the Committee, I acknowledge that many people made very detailed and substantive submissions to this inquiry back in the second half of 2019. Only some of the issues raised in those submissions have been dealt with in public hearings to date. It is the intent of the committee to hold more hearings to delve into the full breadth of the terms of reference now the final EIS is published. The committee thanks very much those witnesses who have given evidence to date and especially those who have given their time during site visits.
I acknowledge the contribution of all members of the committee who have engaged constructively in this inquiry to date. I would also like to thank the secretariat staffnfor their ongoing work in supporting what has become a far longer inquiry process than was originally anticipated.