Chapter 29 - Urban Residential Zone 29.1.5.1.1 Conditions Any increase in the concentration of suspended sediment shall not be more than 20% as measured by the ‘black disk’ method, notwithstanding that the concentration of suspended sediment in run-off water shall not exceed 200grams/ cubic metre at any point of discharge to any receiving water. The effects on the receiving water are to be measured at a distance downstream of two widths of the receiving watercourse or 50 metres, whichever is the lesser; No woody material of greater than 100mm diameter shall be left in any permanently flowing river, lake, wetland or sea as a result of a land disturbance operation; and All land disturbance sites are to be stable when subject to a storm event of 10% probability or less 29.1.5.1.2 Exception Except any land disturbance activity which does not meet the above conditions or is in an area identified as a hazard area that is required for the purposes of constructing or providing access to any structure requiring a building permit under the Building Act 1991, shall be a Discretionary Activity, with no restriction on the exercise of Council’s discretion. 29.1.5.2 Excavation and Filling 29.1.5.2.1 Conditions a) The maximum volume for either excavation or filling shall not exceed 20min any continuous ten year period; 3 b) The gradient of any side cut excavation must not exceed an average of 9.5° (1:6) and must not exceed 11.3° (1:5) along any length of more than 20 metres; c) Stormwater controls, watertable cut-offs, and culverts are to be installed to ensure that erosion does not occur on the inside edge of the cut. No culvert size less than 300mm may be used to drain any side-cut excavation; d) Batters and side castings are to be established by appropriate measures such as seeding, compacting, drainage and/ or other methods of revegetation; e) Run-off from watertables or surfaces of side-cut excavations is to be directed to stable land areas; and f) Except for direct approaches to bridges, crossings and fords; maintenance of rail and public roads; and trenching for cable laying, no excavation or filling must take place within riparian management zones as specified in the schedule of water bodies and Table 1 in Appendix I and as mapped in Volume Three Maps, or in a manner or location where the General Conditions for Land Disturbance above can not be complied with. 29.1.5.2.2 Fill Content In addition to compliance with the conditions relating to the volume of fill material any filling of land or depressions is a Non-Complying Activity where the fill contains: 29 - 5