OPPONENTS of the Inland Rail crossing the Condamine River floodplain say a draft report into flood modelling on the controversial route has identified "discrepancies and unknowns".
Millmerran Rail Group chairman Wes Judd said an independent panel of experts appointed by both the state and federal governments had even accused Australian Rail Track Corporation (the builder of Inland Rail) of withholding information.
"Landholders know only too well how hard it is to get the facts from ARTC, and now the committee appointed by two governments can't get all the information they want to do an assessment on ARTC's work," Mr Judd said.
"This is another example of the Australian Rail Track Corporation acting like the Arrogant Rail Track Corporation."
Mr Judd said it was not surprising the report had not been promoted.
"How can local farmers and residents have confidence in ARTC's flood modelling if flood modelers handpicked by the Australian Government don't," Mr Judd said.
"The fact is landholders can't and don't have confidence in the ARTC."
Mr Judd said the ARTC had put the route, based on incomplete and flawed information, in a draft environment impact statement to the Queensland Government's Coordinator-General.
"It's like sending in incomplete homework and hoping the teacher will give you a pass mark," Mr Judd said.
"The fact is the ARTC deserves a fail; a big F for this rail fail."
ARTC director planning - communications and stakeholder relations, Rebecca Pickering, said now was an excellent time for the input from the panel to assist in the refinement of the flood modelling as ARTC progressed the designs for Inland Rail and consulted with communities.
"The panel's review builds on and acknowledges the substantial amount of work undertaken by ARTC and other world-leading experts to construct Inland Rail in a way that is safe and suited to its environment," Ms Pickering said.
"Amongst the findings of the draft report, the panel has found that ARTC's work predominantly meets Australian guidelines and industry best practice.
"The panel also makes it clear that the findings are as expected for a significant infrastructure project, such as Inland Rail, and are normal for a project of this nature at this time in its development."
The Millmerran Rail Group highlighted the following key extracts from the report:
Page 39: For the Condamine River, the FFA [Flood Frequency Analysis] was undertaken using a non-standard approach whereby the flow record at two gauges located 15km and 40km downstream of the alignment on different waterways was combined. An FFA completed by the panel suggests a flow bias between the North Condamine and Condamine waterways. Additional information is required in relation to the FFA completed together with a comparison with FFAs that have been completed previously.
Page 40: Further, given the uncertainty associated with the applicability of the FFA to a number of catchments... there is a concern based on the use of other methods to estimate flows... that the design peak flows for a number of catchments could be underestimated.
Page 59: 13.1.1 Lack of Detail in Report.
The panel appreciates that ARTC has undertaken significant work and it is difficult to provide an all-inclusive document which captures all the work undertaken. However, the technical report is not sufficiently comprehensive to meet the panel's ToR (terms of reference).
Additional details are required in relation to the calibration of the flood models (for example agreement to recorded levels), the use of flood frequency analyses completed with respect to other catchments, and the modelling of design events (for example critical duration analysis).
Page 60: On 25th November 2020, the FFJV through ARTC design managers, agreed to provide the panel with a technical memo justifying level increases outside the disturbance footprint for the B2G section. The memo was not yet available to the panel at the time of writing and will be considered subject to its availability as part of preparing the final report.
Pages 61-62: 13.1.7 Flood model Setup Issues
A number of model setup issues have been identified for each regional flood model.
While a number of issues are minor and can be resolved as part of further design, for other issues, without additional sensitivity modelling it is uncertain whether the issues will make a material difference to the results achieved to date (and therefore whether changes to the flood model need to be completed as part of the draft EIS finalisation or can be included as a condition of approval).
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