Chapter 26 - General Rules e) Alternatively, a buffer strip of 1 metre width shall be left between the water’s edge and the start of excavation. The excavation shall not disturb flowing water; f) Any excavation shall take place from the downstream end of the gravel beach, working upstream; g) No secondary braids and flow patterns may be opened up, either by extraction, tracking, or other redirection to river flow; h) Holes in the riverbed must not be created; i) Vertical faces must not exceed 1 metre in height; j) Gravel shall not be stockpiled within the riverbed for any period exceeding 24 hours; k) No gravel screening or processing shall take place in the riverbed; l) Oversize boulders or other sediment initially removed from the riverbed, but later considered unsuitable for use may not be disposed of back into the riverbed; m) Reject material shall not be disposed of in wetlands or backwaters; n) Access routes to extraction points shall be planned so as not to cut off flow into minor channels or backwater, or to disturb birds using riparian vegetation; o) The extraction of gravel shall be limited to the hours of 7.30 am - 5.00 pm from Monday to Saturday. No gravel shall be extracted on public holidays or between the periods 24 December to 3 January inclusive; and p) Records are to be kept on a monthly basis of gravel and other sediment removal from riverbeds. 26.1.6.1.11 Stopbank Maintenance and Reconstruction Stopbanks that are structurally weak, damaged or that have developed isolated low points may be reconstructed to the 1% probability design height as a Permitted Activity. 26.1.6.1.12 Lining of Drainage Channels with Timber or Concrete Drainage channels may be lined with timber or concrete for hydraulic efficiency or bank structural stability reasons where the channel is of limited width as a Permitted Activity. 26.1.6.1.13 Drainage Channel Discharges and Flood Control The diversion and discharge by pumping or floodgated gravity outfalls associated with the operation of the existing network drainage channels and small rivers, including the partial control of water levels and flow rates, is a Permitted Activity. 26.1.7 Wetland Drainage 26.1.7.1 Drainage of a wetland under 0.4ha The drainage of a wetland under 0.4ha is permitted, unless identified in part 2 of Appendix B. 26.1.7.2 Drainage of a wetland over 0.4ha The drainage of any wetland over 0.4 hectares is a Discretionary Activity, unless identified in part 2 of Appendix B. 26 - 11