Flood Extent (1% AEP) - Lower Waikato and Waipa Rivers

Purpose: This data has been published to support the Waikato Regional Hazards Portal. This data is part of the River Flooding theme. Statement: 2D flood extent as interpolated from a Mike 21 1D model on to a LiDAR derived topography using WaterRide Software. This information is created by inferring the 1% AEP 1D flood model (2009 TOPNET Design 1958 - 0.2) over the adjacent floodplain to create a 2D representation. There may be some inaccuracies and errors associated with this method. The modelling does not include the predicted effects of climate change on rainfall intensity and sea level rise. These maps do not show internal ponding in overbank areas which is likely in an event. Where stopbanks are overtopped, full flooding is shown. The model also only relates to the main channel, with many tributaries and some overbank areas not included. The presence of a hazard does not guarantee the existence of such a hazard, nor does the lack of information preclude the existence of a hazard or risk. Waikato Regional Council accepts no liability or otherwise resulting from hazards or knowledge of hazards. The information was last updated 09 December 2025. WRC Natural Hazard Information Hierarchy: 2. Local to regional scale Information that is suitable to be used for District or Regional Plans, or as an initial indicator of where further investigation may be required. This information is NOT suitable for use at property scale, or for: • property specific risk assessments • resource or building consents • decisions that concern personal or public safety • the conduct of commercial business • insurance purposes Waikato Regional Council recommends further investigation and using other applicable natural hazard data, if available, for property specific purposes. The information is generally based on modelling or hazard mapping but may not include both current and future possible scenarios. Users should make sure they are using the most appropriate natural hazards data available. Data held by other organisations may be better suited for property scale use or may be more up to date. Before using any of the Waikato Regional Council natural hazard data at property scale or for subdivision development purposes please contact the Waikato Regional Council Regional Resilience team for guidance. Further information on resource consenting is available here. Intended Use Scale: Data should not be used at scales greater than 1:1,250 Data Use Limits: Note there is currently some overlap with the polygon version of this data between Huntly and Horotiu and around Ngaruawahia which may result in minor discrepancies when both layers are viewed together. Data Specific Disclaimers: "The presence of a hazard does not guarantee the existence of such a hazard nor does the lack of information preclude the existence of a hazard or risk. Waikato Regional Council accepts no liability or otherwise resulting from hazards or knowledge of hazards." The standard Waikato Regional Council Disclaimer applies to this data “While Waikato Regional Council has exercised all reasonable skill and care in controlling the contents of this information, Waikato Regional Council accepts no liability in contract, tort or otherwise howsoever, for any loss, damage, injury or expense (whether direct, indirect or consequential) arising out of the provision of this information or its use by you.” There may be derivatives of this layer created and shared by other parties. While Waikato Regional Council has exercised all reasonable skill and care in controlling the contents of this information, Waikato Regional Council accepts no liability in contract, tort or otherwise howsoever, for any loss, damage, injury or expense (whether direct, indirect or consequential) arising out of the provision of derivatives or their use by you.” WRC Metadata: For full metadata search for HAZARD.sdeadmin.HAZ_FLOOD_EXTENT_1_AEP_LINE in HAZARDS - Regional Hazards Portal - GIS Layers or HAZARD.sdeadmin.HAZ_FLOOD_EXTENT_1_AEP_POLY in HAZARDS - Regional Hazards Portal - GIS Layers Terms of Use: This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License. Should users wish to distribute or publish derivatives or modified versions of this data then they must seek a data use agreement through WRC first. See the Waikato Regional Hazards Portal Terms of use here Waikato Regional Hazards Portal - Terms of use | Waikato Regional Council. Updates: Oct 2021: Minor polygon geometry changes around Kellyville, to exclude area protected from flooding, and Ngaruawahia to include river and river mouth of lower Waipa. 09 Dec 2025: Line features for Otorohanga town, landward of the stopbanks and north and south of the Waipa River, was removed as was included in error.用途：本数据集发布旨在支持怀卡托地区灾害门户（Waikato Regional Hazards Portal）建设，属于河流洪水（River Flooding）主题数据集。 说明：本数据集的二维洪水淹没范围，通过WaterRide软件将Mike 21 一维模型（Mike 21 1D model）的计算结果插值到激光雷达（LiDAR）获取的地形上生成。具体实现方式为：将1%年超越概率（1% AEP）的一维洪水模型（2009年TOPNET设计方案1958 - 0.2）推演至相邻漫滩区域，以生成二维可视化表达。 本方法可能存在一定误差与缺陷。本次建模未考虑气候变化对降雨强度与海平面上升的预测影响。本淹没分布图未展示堤内区域在洪水事件中可能出现的内部积水情况。当防洪堤漫顶时，本数据将展示全域淹没情况。本模型仅针对主河道，未涵盖众多支流与部分漫滩区域。 灾害标识的存在不代表该灾害必然发生，信息缺失也不代表该灾害或风险不存在。怀卡托地区议会（Waikato Regional Council，缩写WRC）不对因灾害信息或灾害认知产生的任何后果承担责任。本信息最后更新于2025年12月9日。 怀卡托地区议会自然灾害信息层级：2. 局地至区域尺度 本信息适用于区域或地区规划，或作为初步指示以确定后续需开展调查的区域。本信息不适用于： • 地块尺度风险评估 • 资源或建筑许可审批 • 涉及个人或公共安全的决策 • 商业运营行为 • 保险理赔用途 怀卡托地区议会建议，若需开展地块尺度的相关分析，应开展进一步调研并结合其他可用的自然灾害数据集。本信息通常基于建模或灾害制图生成，但可能未涵盖当前与未来的所有潜在情景。使用者应确保使用的是当前可用的最适宜自然灾害数据。其他机构持有的数据集可能更适用于地块尺度应用，或时效性更强。若需将怀卡托地区议会的自然灾害数据集用于地块尺度或分区开发用途，请联系怀卡托地区议会区域韧性团队获取指导。更多关于资源许可的信息可在此处获取。 适用比例尺：本数据集不适用于比例尺大于1:1250的场景。 数据使用限制：请注意，当前亨特利（Huntly）与霍罗蒂乌（Horotiu）之间、以及纳鲁阿瓦希亚（Ngaruawahia）周边的本数据集多边形版本存在部分重叠，同时加载两层时可能产生细微偏差。 数据专属免责声明："灾害标识的存在不代表该灾害必然发生，信息缺失也不代表该灾害或风险不存在。怀卡托地区议会不对因灾害信息或灾害认知产生的任何后果承担责任。" 本数据集适用怀卡托地区议会标准免责条款："尽管怀卡托地区议会已尽合理技能与谨慎义务管控本信息内容，但怀卡托地区议会不对因提供本信息或您使用本信息所引发的任何损失、损害、伤害或开支（包括直接、间接或后果性损失）承担任何合同、侵权或其他形式的责任。" 第三方可能会创建并分享本图层的衍生版本。尽管怀卡托地区议会已尽合理技能与谨慎义务管控本信息内容，但怀卡托地区议会不对因提供该衍生版本或您使用该衍生版本所引发的任何损失、损害、伤害或开支（包括直接、间接或后果性损失）承担任何合同、侵权或其他形式的责任。 怀卡托地区议会元数据：完整元数据可在灾害 - 地区灾害门户 - GIS图层中搜索`HAZARD.sdeadmin.HAZ_FLOOD_EXTENT_1_AEP_LINE`或`HAZARD.sdeadmin.HAZ_FLOOD_EXTENT_1_AEP_POLY`获取。 使用条款：本作品采用知识共享署名-禁止演绎4.0国际许可协议（Creative Commons Attribution-NoDerivatives 4.0 International License）进行许可。若使用者希望分发或发布本数据集的衍生版本或修改版本，需先通过怀卡托地区议会申请数据使用许可。详见怀卡托地区灾害门户使用条款：怀卡托地区灾害门户 - 使用条款 | 怀卡托地区议会。 更新记录：2021年10月：对凯利维尔（Kellyville）周边的多边形几何进行小幅调整，移除了受防洪保护的区域；对纳鲁阿瓦希亚区域进行调整，纳入了下怀帕河的河道与河口区域。2025年12月9日：移除了奥托罗杭加（Otorohanga）镇、防洪堤内侧以及怀帕河南北两侧的线状要素，该部分要素此前因录入错误被包含在内。