No Tillegra Dam Group

The official submissions to the Department of Planning for the Part 3A application from both the NSW Office of Water  and the Hunter-Central Rivers Catchment Management Authority  (CMA) are deeply critical, suggesting that the proposal does not conform to state law and policy and is based on outdated climate change information and would damage the lower Hunter wetlands. There are clear official calls to stop the $450m Tillegra Dam.

CMA submission

The CMA submission is signed by its General Manager Fiona Marshall and is an official document. It is critical of the assessment of the need for the dam, suggesting that Hunter Water has exaggerated the impacts of both climate change on existing supplies and population growth on demand.

The CMA is telling the Department of Planning that Hunter Water is wrong on two of its key justifications for proceeding with Tillegra.

The CMA also strongly criticised the assessment of the dam on the Williams River, the Hunter wetlands and the inundation area, using terms like “misleading”, “fails to use the most up to date information” and “catastrophic”.

The CMA concludes that the modelling of impacts is inadequate.

CMA’s criticism of the modelling and impacts on the lower Hunter wetlands is particularly significant as it is on the future of these  that Federal Environment Minister Peter Garrett is making his determination.

Specific findings in the CMA’s submission are:

• climate change conclusions “are not an adequate reflection of current climate information”. This has major consequences for the case for Tillegra. More recent information suggests that climate change will not reduce inflows into existing storages to the extent predicted in the EAR, and might actually increase the amount of water available without Tillegra;
• the impacts of predicted population increases on the need for new water supply options have been overstated: “It does not make sense that for every 1% of population growth an additional 1.6% demand in water is experienced”.
• “fails to recognise the environmental impacts of the dam.” and “[T] cost analysis fails to value the biodiversity impacts of the dam”.
• native vegetation impact understated and unacceptable: “under normal circumstances the proposal would not be likely to be able to proceed due to the vegetation to be cleared … [including] potential Endangered Ecological Communities”. “Misleading” statement about the proposed offsets for native vegetation clearing. “The CMA disagrees with the statement that loss of 224ha of vegetation is a small impact”. “The CMA considers that a loss of 145ha is a significant and unsustainable loss”. The CMA challenges the description of the riparian vegetation as “degraded”.

• CMA concerned that “impacts of dam [on rivers and water] is not adequately addressed in the EA”: “The reference to removing in-stream vegetation … is misinformed. … Current legislation needs to be considered”. “The descriptions of the fluvial geomorphology fail to use the most up to date and consistent information.” “The claims of only localised scour cannot be justified”.

• The risk assessment  on aquatic ecology above the dam were classed as “moderate.” “This should be catastrophic” .

• “The CMA disagrees with the assessment that this impact [on the Ramsar listed Hunter wetlands] will not be significant.”

Office of Water Submission

The Office of Water (NOW) EAR submission was signed by Mark Mignanelli, Manager Major Projects and Assessments.  Mr Mignanelli had previously advised the Minister that Tillegra dam would not be needed for 30 years.  He had also recommended potential water efficiency gains using existing infrastructure as an alternative to the construction of Tillegra.

The NOW document emphasised that the Tillegra dam proposal “will not meet the objects and principles of NSW water legislation and policy” and acknowledged that “there will be unavoidable ecological and geomorphic consequences for the Williams River.”

Some other specific findings are:

• there will be “long term impacts of Tillegra that cannot be mitigated”
• contrary to the EAR, “ ecological processes within the Williams River will be impacted by geomorphic change”
• “a storage of this nature will be expected to have significant adverse effects on the environmental values of the Williams River”
• “the existing cumulative impacts of Chichester, Seaham Weir and Grahamstown Extractions will be increased by the construction of Tillegra Dam
• the model used to determine impacts to the Hunter estuary from modification to freshwater inflow completely ignores the dynamic nature of the salinity characteristics of the estuary
• NOW is not confident that the information for the Project is adequate to frame environmental flow provisions for Seaham Weir or Tillegra Dam