Housing developers. While the dam wall raising was proposed in 2016 by the Baird (NSW Liberal) Government, it is land developers on the Hawkesbury-Nepean floodplain who seek to benefit for the dam wall raising. The NSW Government has itself stated that it plans to allow developers to place and additional 134,000 people on the floodplain once the dam wall is raised - doubling the existing floodplain population.
The southern Blue Mountains is an extensive and rich cultural landscape belonging to the Gundungurra People. The rivers, waterholes and mountains of the Blue Mountains landscape tell one of the most intact and documented dream-time stories in Australia - the epic battle of tiger cat (Mirrigan) and snake (Gurrangatch) which formed the southern Blue Mountains.
When Warragamba Dam was built in 1960 it resulted in the flooding of a large proportion of the cultural heritage and dreamtime stories of the Gundungurra people. If the dam wall is raised the remaining sites of this story - including Indigenous archeological sites, creation waterholes and cave art - will be destroyed.
An indigenous cave art site that would be inundated.
They have already applied for an Aboriginal Place nomination to the NSW Government to try and stop the dam raising destroying their last cultural sites [i]. By getting involved with the campaign, you can assist the Gundungurra people save their remaining cultural heritage from destruction. Having lost so much already, we need to make sure we stop the dam raising to protect what is left.
[i] Isla Cunningham (2018) Gundungurra Group Lodge Proposal to Protect Sacred Sites at risk in Warragamba Dam Plan, The Blue Mountains Gazette. Available Online: https://bit.ly/2NN8xbp
The Hawkesbury-Nepean Valley is particularly prone to flooding as it is naturally constricted in two places that, in conditions of severe rainfall, results in floodwaters backing up and inundating floodplains in north-west Sydney.
Alternative flood management options have additional benefits for western Sydney, including greater safety for the most flood prone residents, better transport, a more vibrant agricultural sector, a healthier environment and improved water security.
Importantly, half of all floodwaters in the Hawkesbury-Nepean originate from catchment areas that are not upstream of Warragamba Dam [i]. This means that even if a raised Warragamba Dam was to hold back some flood waters, other catchments could still cause significant flooding in the valley. In fact, flood waters from the Grose River alone can cause moderate to major flooding of Richmond in the lower Hawkesbury [ii].
You can read Assoc. Prof Jamie Pittock's full report on the alternatives to raising Warragamba Dam wall here.
[i] Department of Primary Industries (2014), Office of Water. Hawkesbury-Nepean Valley Flood Management Review Stage One. Available Online: https://bit.ly/2JxtchB
[ii] Australian Water and Coastal Studies (AWACS). 1997. Lower Hawkesbury River Flood Study. Prepared for NSW Department of Land and Water Conservation, Sydney.
The dam raising is being driven by developer interests on the Hawkesbury-Nepean floodplain. 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 [i].
Infrastructure NSW map showing planned development areas on the Hawkesbury-Nepean floodplain [ii].
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 [iii]. International best practice dictates that floodplain development should not occur below the 1:500 year level [ix].
Minister Ayres, the Minister for Western Sydney has himself said that he plans for future development across the low-lying Penrith floodplain "as far as the eye can see" in the coming years [x].
The Western Sydney Leadership Council's chairman, Christopher Brown, has flagged developing flood-prone land as a potential funding source for the dam wall extension [xi], saying:
"I think there's the capacity to use a value-capture funding method to reduce the impact on taxpayers," he said.
"Maybe via levy on land release that was previously considered flood-prone so we might be able to do it at a cheaper rate than what the Government's talking about."
[i] Infrastructure NSW (2017), Hawkesbury-Nepean Valley Flood Risk Management Strategy, page 3. Available online: https://bit.ly/2wDd4VL
[ii] Molino Stewart (2012), Hawkesbury-Nepean Flood Damages Assessment, Prepared for Infrastructure NSW, page 15. Available online: https://bit.ly/2MXahcH
[iii] Environmental Planning and Assessment Act 1979, State Environmental Planning Policy (Penrith Lakes Scheme) Amendment 2017, page 19. Available online: https://bit.ly/2PrXwrT
[ix] Caroline Wenger, Karen Hussey & Jamie Pittock (2012) The Use of the 1:100 Year Standard in the United States: Insights for Australia? Australian Environment Review, Vol. 27, pages 337-342
[x] Channel 9 News (2014) 4th of December 2014 News Coverage of Penrith Lakes. Available online: https://bit.ly/2EpcaPu
[xi] Sarah Gerathy (2016) Warragamba Dam: Wall Flood-Protection Plan Raises Environmental Concerns, Australian Broadcasting Company. Available online: https://ab.co/2G8np0E
The Government has stated that inundation by sediment-laden flood waters would occur in the World Heritage Area for five weeks at a time [i]. Based on WaterNSW published flood levels, up to 4,700 hectares of the World Heritage listed Blue Mountains National Parks and 65 kilometres of wilderness streams would be inundated by the 14-metre dam wall raising [ii].
The wild rivers of the southern Blue Mountains form a landscape that has been largely untouched by modern society. The area is home to 48 threatened plant and animal species, ancient river valleys, rare dry rainforests and hundreds of Indigenous cultural sites [iii]. The significance of the southern Blue Mountains landscape led it to being inscribed on the World Heritage List in 2000.
The Regent Honeyeater is currently listed as Critically Endangered. The Burragorang Valley floor, to be inundated by the proposed raising of Warragamba Dam wall, is the most fertile regional habitat and key breeding site for this species [iv]. Impacts on one habitat (e.g. the Burragorang Valley) cannot be offset by improvements in another due to the rotational use of habitats by the species.
The lower Nattai Valley is home to one of Sydney’s refuge koala populations. The valley will be inundated by the raising of the Warragamba Dam wall raising.
[i] WaterNSW (2016), Warragamba Dam Raising Preliminary Environmental Assessment, page 24. Prepared by BMT WBM Pty Ltd, Sydney. Available online: https://bit.ly/2rzXjtz
[ii] WaterNSW (2016), Warragamba Dam Raising Preliminary Environmental Assessment, page 26. Prepared by BMT WBM Pty Ltd, Sydney. Available online: https://bit.ly/2rzXjtz
[iii] ibid
[iv] Ross Crates et al. (2018) Submission to the New South Wales Legislative Council’s inquiry into the Water NSW Amendment (Warragamba) Bill 2018, Inquiry into Water NSW Amendment (Warragamba Dam) Bill 2018. Available Online: https://bit.ly/2UsVs6F