Appendix B—Assumed flow regime changes To develop prefeasibility cost estimates, it was necessary to define a flow regime, and “baseline” a flow regime, as inputs to the costing methods. “post-CMS” The flow regime was assumed to be represented by modelling outputs from the “baseline” MDBA’s diversion limit” (BDL) model run. “baseline The flow regime was assumed to be represented by modelling outputs from “post-CMS” the MDBA’s run. “BP2800RC” The model run represented, as of August 2014, the best available information on a “BP2800RC” post-CMS flow regime. The flow regime represented the most appropriate baseline for cost estimates, noting that: “BDL” The Basin Plan is expected to result in a different flow regime (e.g. the modelled flow regime) to the flow regime. The change to a flow regime “BP2800” “BDL” “post-CMS” could, in theory, be represented by the difference between the flow regime and “BP2800” the flow regime. “post-CMS” However, the Basin Plan has not yet been fully implemented. At the present time the flow regime is a purely hypothetical flow regime that has not yet been realised. “BP2800” The costs that will be incurred in implementing mitigation options (e.g. easements or infrastructure works) would reflect the outcomes of negotiations with stakeholders, who will need to agree to those options, and associated funding, before they can be implemented. Therefore, if mitigation options (e.g. easements and/or infrastructure were to be pursued, negotiations over costs would necessarily be with reference to a “baseline” which is defined by recent lived experiences. Because of point (2) above, recent lived experiences do not correspond to the “BP2800” flow regime. Rather, the flow regime is an appropriate modelled representation of “BDL” this baseline. It is therefore considered a more meaningful baseline for the estimation of the actual costs that would be occurred. The above assumptions were considered appropriate for CMS prefeasibility purposes. If the CMS were to progress to feasibility or beyond, it will likely be appropriate to use different hydrological assumptions as a basis for negotiating costs.
Appendix B—Assumed flow regime changes To develop prefeasibility cost estimates, it was necessary to define a “baseline” flow regime, and a “post-CMS” flow regime, as inputs to the costing methods. The “baseline” flow regime was assumed to be represented by modelling outputs from the MDBA’s “baseline diversion limit” (BDL) model run. The “post-CMS” flow regime was assumed to be represented by modelling outputs from the MDBA’s “BP2800RC” run. The “BP2800RC” model run represented, as of August 2014, the best available information on a post-CMS flow regime. The “BDL” flow regime represented the most appropriate baseline for cost estimates, noting that: The Basin Plan is expected to result in a different flow regime (e.g. the modelled “BP2800” flow regime) to the “BDL” flow regime. The change to a “post-CMS” flow regime could, in theory, be represented by the difference between the “BP2800” flow regime and the “post-CMS” flow regime. However, the Basin Plan has not yet been fully implemented. At the present time the “BP2800” flow regime is a purely hypothetical flow regime that has not yet been realised. The costs that will be incurred in implementing mitigation options (e.g. easements or infrastructure works) would reflect the outcomes of negotiations with stakeholders, who will need to agree to those options, and associated funding, before they can be implemented. Therefore, if mitigation options (e.g. easements and/or infrastructure were to be pursued, negotiations over costs would necessarily be with reference to a “baseline” which is defined by recent lived experiences. Because of point (2) above, recent lived experiences do not correspond to the “BP2800” flow regime. Rather, the “BDL” flow regime is an appropriate modelled representation of this baseline. It is therefore considered a more meaningful baseline for the estimation of the actual costs that would be occurred. The above assumptions were considered appropriate for CMS prefeasibility purposes. If the CMS were to progress to feasibility or beyond, it will likely be appropriate to use different hydrological assumptions as a basis for negotiating costs.