Document ID: chunk:federal_register_of_legislation:F2024C00760:reg:80:p5
Version: federal_register_of_legislation:F2024C00760
Segment Type: reg
Provision Reference: reg 80 (pt 5/9)
Character Range: 590488–593556

are capable of supporting species listed in those agreements; or
                (ii) are natural or near‑natural, rare or unique; or
                (iii) provide vital habitat; or
                (iv) support Commonwealth, State or Territory listed threatened species or communities; or
                (v) support, or with environmental watering are capable of supporting, significant biodiversity;
            (b) the relative area of water‑dependent ecosystems in the reach inundated under the flow event target;
            (c) ecosystem functions provided by the flow regimes.

S6.06 How the method is to be applied
(1) The method is based on the achievement of the same overall environmental scores for each region under:
            (a) the benchmark model run; and
            (b) a run with an SDL adjusted for the supply contribution together with the improved environmental outcomes associated with the supply measures being considered.
(2) For any model run the score for each reach, and cumulatively the overall score, is that resulting from the following steps:
            (a) calculate the flow event frequency and dry spell statistics from the modelling;
            (b) convert that calculation to a measure of environmental outcome by the application of preference curves;
            (c) combine flow event frequency and dry spell measures of environmental outcome according to a science based, independently reviewed, fit for purpose rules‑based approach, to derive a single measure for each flow target;
            (d) weight by the environmental significance of the various components of the flood dependent area in each reach;
            (e) combine, according to a science based, independently reviewed, fit for purpose approach, the scores for each flow event target to ascertain the score for the reach; and
            (f) combine the scores for all reaches within a region to ascertain the score for the region.
Note: Scoring will need to occur separately for areas with environmental works and for areas without works and then combined within the scoring method.
(3) Hydrologic modelling under the method to establish a supply contribution will start with the benchmark environmental flow events and these will only be modified as necessary to reflect the outcomes of the proposal and potential supply contribution.
(4) The supply contribution method can be applied to all surface water SDL resource units within the Basin.
Note: The method may be applied using separate modelling runs for the northern and southern Basin, or parts thereof, as necessary to determine relevant supply contributions. For example, if there are no proposed supply contribution measures for a tributary, it would not be necessary to develop scoring metrics for that tributary provided that the in‑valley recovery volume is maintained.

S6.07 Limits of changes in score or outcomes
The following limits of change in score or outcome will apply in the method under the historic climate conditions:
            (a) for each region of the Basin—no reduction in