Option 2 – SIS 86% $ 66,010,039 $ 1,190,140 Basin Salinity Target maintained (<800 EC 95% of the time) No capacity to buffer jurisdictional use of register credits and the potential emergence of delayed salinity impacts Reduced capacity to protect river from salinity threat during extended drought when there are minimal options for mitigation with flows Some reduction in ‘headroom’ and hence some reduction in the frequency of meeting Basin Plan operational targets. Reduction of economic benefits depending upon location of schemes targeted for reduced operations Depending upon the sites targeted for reduced operation potential loss of some environmental benefits of SIS. Qualitative scoring of Option 2 3 3 -1 -1 Total Score Option 2 = +1
Option 3 – SIS 77% $ 72,241,170 $ 800,694 Basin Salinity Target exceeded (<800 EC 93% of time). Potential for a worse outcome if jurisdictions utilise their register credits or if there is a more rapid emergence of delayed salinity impacts Further reductions in capacity to protect river from salinity threat during extended drought when there are minimal options for mitigation with flows Reduces ‘headroom’ leading to a further reduction in the frequency of meeting Basin Plan operational targets Further reduction of economic benefits depending upon location of schemes targeted for reduced operations Depending upon the sites targeted for reduced operation potential loss of some environmental benefits of SIS Qualitative scoring of Option 3 +2 +2 -3 -3 Total Score option 3 = -0.5
Option 4 – SIS 50% $ 67,551,405 $ 1,093,805 Basin Salinity Target exceeded (<800 EC 89% of time). Significant reduction in capacity to protect river from salinity threat during extended drought when there are minimal options for mitigation with flows High incidence of not achieving Basin Plan operational targets Potentially a large reduction in economic benefits depending upon location of schemes targeted for reduced operations Depending upon the sites targeted for reduced operation potential loss of some environmental benefits of SIS Qualitative scoring of Option 4 +3 +3 -4 -4 Total Score option 4 = -0.5
Table 14 Joint program components (other elements) ID Joint program components Indicative importance and investment options Notes / other considerations Element 1: Flow management component of joint works and measures 1.1 Capture and analyse experiences in managing peak salinity events. Optimal: Assessment will be at a key site level using updated modelling. Reduced: Assessment will provide less detail (i.e. either at a sample of key sites or regional level) using updated modelling. This activity may be included as part of another major activity such as 1.2 or 4.2 1.2 Investigate ways in which dilution effects of all water in the system (including both consumptive and environmental water) could be used to enhance salinity mitigation benefits. Optimal: Assessment will be at a key site level using updated modelling. Reduced: Assessment will provide less detail (i.e. either at a sample of key sites or regional level) using updated modelling. As the environmental watering activities progress and their impacts are better understood, ways in which dilution effects to enhance salinity mitigation benefits may be developed over several years and are likely to be ongoing over the life of the BSM2030. 1.3 Develop potential approaches to flow management that seek to pursue salinity management outcomes which could be incorporated into relevant planning documents and processes. These costs are fixed as they are to be incorporated into existing planning and operational processes. However their effectiveness and robustness will be enhanced by implementation of components 1.1 and 1.2. Environmental watering strategies, priorities and schedules are expected to evolve over time. The development of approaches that provide complementary salinity outcomes will therefore also be ongoing. 1.4 Progressive review of river operation rules. These costs are fixed as they are to be incorporated into existing planning and operational processes. However their effectiveness and robustness will be enhanced by implementation of components 1.1 and 1.2. This activity may require more effort in the first years of BSM2030. However, a scaled-down ongoing effort may apply depending on future flow management decisions.
Net ‘Legacy of History’ Impacts (Register B) +5.3 +0.9 +3.4 +1 - Total Register B Balance 20 -14.01 -3.8 +0.35 -9.86 - Total Register Balance 20– All states and the River -165.2 -36.92 -26.68 -44.79 -56.12
Social, environmental, or economic impacts Maintain existing economic benefits Maintain complementary social and environmental benefits from SIS that are not explicitly considered in the approvals process for SIS. Reduction of economic benefits depending upon location of schemes (could be in the order of ~$5m/year or a 4% reduction from Option 1 ) Depending upon the sites targeted for reduced operation potential loss of some environmental benefits of SIS. Further reduction of economic benefits depending upon location of schemes (could be a reduction of between $5m and $18m/year or a 4%-17% reduction from Option 1 ) Depending upon the sites targeted for reduced operation potential loss of some environmental benefits of SIS. Potentially a large reduction in economic benefits depending upon location of schemes (could be in the order of ~$18m/year or a 17% reduction from Option 1 ) Depending upon the sites targeted for reduced operation potential loss of some environmental benefits of SIS.