The Power of Commitment iv 4.1.1 Mataura Stream.....................................................................................35 4.1.2 Wharekirauponga Stream......................................................................35 4.1.3 Ohinemuri River..................................................................................... 36 4.2 Current and Predicted Source Water Quality Summary 36 4.3 Decant Water Treatment 40 5 COLLECTION PONDS.............................................................................................. 42 5.1 Willows Rock Stack Collection Pond 42 5.2 TSF3 Collection Pond (S7) 44 6 SITE WATER BALANCE .......................................................................................... 46 6.1 Model Overview 46 6.1.1 Wharekirauponga Operations ................................................................46 6.1.2 Waihi Operations ...................................................................................49 6.2 WUG WBM Outputs 51 6.2.1 WRS and Groundwater Inflow Water .....................................................51 6.2.2 Mataura Stream Water Quality ..............................................................53 6.3 Waihi WBM Outputs 54 6.3.1 MUG Mine Dewatering ..........................................................................54 6.3.2 Quarterly Water Balance .......................................................................58 6.3.3 Modelled Excess Flows ......................................................................... 60 6.3.4 TSF Overflow Potential .......................................................................... 62 6.3.5 WTP Discharge Water Quality ...............................................................64 6.3.6 Ohinemuri River Water Quality Compliance...........................................66 6.3.7 Seasonal Ohinemuri River Water Quality...............................................68 6.3.8 LOM Ohinemuri River Water Quality...................................................... 69 7 CONCLUSIONS ........................................................................................................ 71 8 RECOMMENDATIONS.............................................................................................. 73 9 REFERENCES .......................................................................................................... 76 Table index Table 1 WTP discharge under various operating regimes 12 Table 2 Calculated WTP Inflow Concentrations and Removal Rates (2019-2020) 14 Table 3 Regime B Discharge Water Quality 15 Table 4 Regime D Discharge Water Quality 16 Table 5 Ohinemuri in-stream water quality at sample locations OH5 and OH6 17 Table 6 Collection Ponds and Status 18 Table 7 Golden Cross Annual Rainfall 23 Table 8 Waihi Annual Rainfall 24 Table 9 Estimation of 100 year ARI flood flow in Mataura Stream adjacent to proposed portal infrastructure 32
RkJQdWJsaXNoZXIy MjE2NDg3