11. Natural Hazards Volume One Rules will be used to set minimum standards for the investigation of subsoils of land zoned Urban Residential 2 – Greenfields. In the event of proposals for the subdivision of land for residential purposes, the investigations will establish the risk of liquefaction and lateral spread and the need for specific foundation design of buildings to mitigate this risk. Resource consent will be required to undertake land uses within the Floodway Zone to ensure that the activity does not reduce the capacity of any floodway or otherwise impair flood flow. Land uses to be controlled include: • construction of structures; • inappropriate planting or removal of vegetation; and • deposition of cleanfill and other material. This will allow the policies of this chapter to be applied to determine whether it is appropriate to undertake activities that have the potential to inhibit the channel efficiency of floodways. Permitted activity standards will be used to establish appropriate setbacks for activities from stopbanks or any other flood mitigation structure. Resource consent will be required to undertake specified activities within close proximity to these flood defences to ensure that they do not adversely affect the effectiveness of the defence. Permitted activity rules will be used to enable the Council to undertake the maintenance and repair of existing flood defences and other flood mitigation works. The permitted activity rules will link to works required to achieve and maintain the design intentions established for the waterbody/drainage channel. Works include gravel extraction required to maintain floodway capacity. Permitted activity standards will be used to establish appropriate setbacks for: • dwellings and other habitable buildings from existing commercial forestry plantations; and • commercial forestry plantations from existing dwellings and other habitable structures. [D] 11.M.5 District rules Applications for subdivision consent involving land likely to be subject to material damage by erosion, falling debris, subsidence, slippage or inundation, will be required to demonstrate that a safe and stable building platform exists for each proposed allotment and the balance parcel. The building platform must be shown on the scheme plan and be supported by a report prepared by a chartered professional engineer with relevant skills and consistent with any relevant Council standards. [R, D] 11.M.6 Building Act 2004 The Building Act 2004 requires a building consent to be refused for the construction of a building or major alterations to a building if land on which the building work is to be carried out is subject to, or is likely to be subject to, natural hazards. Consent is also to be refused if the building work will accelerate, worsen or result in a natural hazard on that land or any other property. A minimum floor level will be established for new dwellings and other new habitable structures where those structures are proposed to be constructed on land subject to a Level 1 flood hazard. The floor level will be a minimum of 450 mm above natural ground conditions. Site specific factors, especially the elevation of the land at the site of the proposed building platform, will determine the minimum floor level. 11 – 14