2022-09-06 P&E Agenda - Item 5 - Attachment 1 - Six Mile Creek Bridge Replacement Offset Report - TMR

Based on these assumptions, an offset area of 0.9 ha will provide approximately 100.49% of the direct offset
requirement. These estimates will be revised when an offset area is identified.
Table 3.2.     Assumptions used to determine offset obligations using the Commonwealth Offset Assessment
               Guide

 Offset Assessment Guide item                                          Value used (assumed# or derived from the Commonwealth
                                                                       Offset Assessment Guide*) (refer Appendix B)
 Total quantum of impact (refer Table 3.1)                             0.12 ha*
 Risk-related time horizon                                             20 years#
 Time until ecological benefit                                         20 years#
 Offset site starting quality                                          5#
 Offset site quality without offsets                                   5#
 Risk of loss without offset                                           90%#
 Offset site quality with offset                                       7#
 Risk of loss with offset                                              10%#
 Confidence in result                                                  90%#
 Proposed offset area                                                  0.9 ha#
 Proportion of impact area offset                                      100.49%*



3.2.3.5        Provision of environmental offsets in accordance with the Queensland
               Environmental Offsets Policy – Koala habitat (also comprising habitat for
               Grey-headed flying-fox)
Whilst the Koala and Grey-headed flying-fox were identified as unlikely to be subject to significant impacts
when assessed against the Significant impact guidelines 1.1 (DotE 2013) as a result of the proposed action
(refer Section 2.3.1 and Section 2.3.2), it is proposed that offsets that would provide habitat for both of these
species will be provided under the Queensland Environmental Offsets Policy. It is noted that under the
provisions of the Queensland Nature Conservation Act 1992 (NC Act), the Grey-headed flying-fox is listed as
a “least concern” species. Therefore, the offset calculations have been undertaken using the Koala, which is
listed as “vulnerable” under the provisions of the NC Act. Given that habitat for both the Koala and the Grey-
headed flying-fox are co-located within the area encompassed by the proposed action, offset delivery for the
Koala would also result in a net ecological gain for the Grey-headed flying-fox.
As indicated in Table 1.1, the Queensland Environmental Offsets Policy is a statutory instrument which is a
decision-making support tool when an environmental offset is required for significant residual impacts to
prescribed environmental matters including Matters of State Environmental Significance (MSES). Under the
Queensland Environmental Offsets Policy, an offsets package may include land-based offsets, actions in a
direct benefit management plan or a financial settlement offset. The quantum (Cost and/or Land area) of an
environmental offset under the policy, is calculated in accordance with the Financial Settlement Offset
Calculation Methodology presented in the Queensland Environmental Offsets Policy. A Financial Settlement
Offset Calculator service is provided by the Queensland Government (refer:
https://apps.des.qld.gov.au/offsets-calculator/) to assist in the determination of offset obligations where
significant impacts are expected to prescribed environmental matters. This online calculator has been used
to determine offset obligations (in relation to land-based and financial settlement options) associated with the
removal of Koala habitat associated with the proposed action.
It is noted that methodologies to calculate Koala offset obligations within Appendix A (Section 8.2), utilised
preliminary estimates that have subsequently been refined through design revision. Therefore, this section
provides a recalculation of the quantum of proposed offset to achieve a net ecological benefit for Koala (and
Grey-headed flying fox) where the quantum of impact associated with the proposed action is 3.17 ha.
Results from the offset calculations are provided in Table 3.3.




                                   Project number 511784 File Six Mile Creek - Matters of National Environmental Significance Report 2021-12-03 Revision 1   36