9 Section 3 is within the bush area and steep topography. The temporary clean water diversion constructed as part of the works shown on ESCP-TSF3-002-03 will be removed. A focus through this section will be on constructing the permanent diversion drain using a cut and cover methodology. Where this is not possible, silt fences, DEBs may be used, or runoff could be diverted down into the impoundment area of TSF3 and ultimately captured by the Collection Ponds. 2.6. Stage 6 Refer to ESC-TSF3-006-01 Full site establishment. 2.7. Rehabilitation Engineering Geology Limited have provided a rehabilitation plan for TSF3 which includes: - Rehabilitation of stockpiles. - Permanent diversion drain remains, but flow directed into closure pond/wetland. - Impoundment area of TSF3 converted into a closure pond/wetland. - Converting the Collection Ponds into a wetland with an open channel to the Ruahorehore Stream. This detail is provided on drawing WAI-983-080-DWG-CI-0960, prepared by Engineering Geology Limited. 3. EROSION AND SEDIMENT CONTROL DETAILS The erosion and sediment control methodology has been designed in accordance with best practice and the principles outlined in TR2009/02. Specific erosion and sediment control calculations and drawings can be found within the appendices. Appendix A – Erosion and sediment control drawings: ESCP-TSF3-001-01 ESCP-TSF3-001-02 ESCP-TSF3-001-03 ESCP-TSF3-001-04 ESCP-TSF3-002-01 ESCP-TSF3-002-02 ESCP-TSF3-002-03 ESCP-TSF3-002-04 ESCP-TSF3-003-01 ESCP-TSF3-004-01 ESCP-TSF3-005-01 ESCP-TSF3-005-02 ESCP-TSF3-006-01 3.1. Clean Water Diversions Perimeter bunding will be used, as required, to divert areas of clean water away from the site. The perimeter bunds will generally be constructed using stripped topsoil and will be stabilised immediately following construction. TR2009/02 recommends that clean water diversions are designed to carry the flow from the 20% annual exceedance probability (AEP) rain event (plus 300mm freeboard). Where possible the clean water diversions have been increased in size to convey the 5% AEP storm event, including a freeboard of 300mm. Calculations
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