The flood plains indicate the area of land inundated by runoff in a storm event that has a 1 percent or greater probability of occurring in any given year, assuming maximum probable development (MPD) and future climate change. The flood plains are mapped from hydraulic modelling results. Information specific to each flood plain is accessible using the Identify tool, including the flood report. This dataset is continually updated at catchment scale to reflect the best information available.This dataset is updated by the Heathy Waters team on a regular basis.Disclaimer: In using the Catchments and Hydrology data set, you acknowledge that you have read, understood and agreed to the disclaimers below.The flood plains and flood sensitive area data layers are generated from catchment level modelling based on the datasets, requirements and technology available at the time of model build. They are compiled regional layers with varied data uncertainty and currency, which may directly impact data accuracy for the area of interest. The information provided therefore does not preclude the need for appropriate site-specific assessment and cannot be construed as an endorsement or approval of any development by Auckland Council.The Catchments and Hydrology data set is updated regularly when new information becomes available. As such, downloading and copying activities may result in data invalidity.Whilst due care has been taken in producing the Catchments and Hydrology data sets, Auckland Council gives no warranty as to the accuracy and completeness of any information given and accepts no liability for any error, omission or use of the information.

Gate opened and closed to admit or exclude water.

Data Dictionary for floodgate_pnt: https://docs.topo.linz.govt.nz/data-dictionary/tdd-class-floodgate_pnt.html

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50: http://www.linz.govt.nz/topography/topo-maps/topo50

Much of the settled Hawke’s Bay region is low lying and built on river flood plains. This brings the risk of flooding, which is our most common natural hazard - a severe storm or flood happens every 10 years on average. Major storms affect wide areas and can be accompanied by strong winds, heavy rain or snowfall, thunder, lightning, and rough seas. They can cause damage to property and infrastructure, affect crops and livestock, disrupt essential services and cause coastal inundation.Rivers normally flood every winter when a storm brings more rainwater than can soak into the soil. When floods threaten communities the flood become a hazard. In Hawke's Bay stop banks have been built alongside many of the rivers to hold in the extra flood water. However in a severe storm, rivers could breach stop banks and the flood waters may go through farms, homes, shops, schools and damage roads and other infrastructure.There have been significant flood protection systems completed on the Heretaunga Plains and the Ruataniwha Plains. Flood protection works in Hawke’s Bay are generally designed to contain a 1% annual exceedance probability (AEP) flood). These works have significantly reduced the effect of small to medium sized floods, but a large flood could overwhelm the works and have a devastating effect. Such a flood, which exceeds the design capacity of the flood protection system, is called a Super Design Flood. Flooding from localised downpours in urban areas can also overwhelm drainage systems, so events below the AEP can still be costly.With climate change, rainfall patterns in the Hawke’s Bay are expected to change over the next century; winters are predicted to become drier, but overall flood risk is expected to increase as single events may be more intense.

Areas adjacent to the 100yr ARI floodplain that are within 0.5m of the predicted 100yr ARI flood level. These mapped areas are to ensure the appropriate planning rules are considered for properties developing adjacent to the floodplain Created by the Stormwater Hydraulic Modelling Team Last Update 23 May 2013Disclaimer: In using the Catchments and Hydrology data set, you acknowledge that you have read, understood and agreed to the disclaimers below.The flood plains and flood sensitive area data layers are generated from catchment level modelling based on the datasets, requirements and technology available at the time of model build. They are compiled regional layers with varied data uncertainty and currency, which may directly impact data accuracy for the area of interest. The information provided therefore does not preclude the need for appropriate site-specific assessment and cannot be construed as an endorsement or approval of any development by Auckland Council.The Catchments and Hydrology data set is updated regularly when new information becomes available. As such, downloading and copying activities may result in data invalidity.Whilst due care has been taken in producing the Catchments and Hydrology data sets, Auckland Council gives no warranty as to the accuracy and completeness of any information given and accepts no liability for any error, omission or use of the information.

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Waikato District Council - Proposed District Plan (Stage 2 Natural Hazards), Notified 27 July 2020. This layer is a spatial representation of an overlay in the Proposed District Plan and indicates where land use will be regulated by various associated rules. It will be used as a guide in the regulatory process of implementing the Proposed District Plan and managing land use, subdivision, the environment and economy. This dataset is subject to changes undertaken through the Resource Management act.Note individual Proposed Plan rules can have different statuses, some may have current legal effect and others will not until the Proposed Plan becomes operative. This data is provided for use in the District Plan only.

Flood Ponding Areas are areas of land that experience floodwater ponding in a 1% Annual Exceedance Probability (AEP) rainfall event. Only two Flood Ponding Areas have been specifically identified on the planning maps. One of the areas is located in the southern part of Huntly adjacent to the eastern bank of the Waikato River and the other is in Huntly West adjacent to Lake Waahi and Lake Puketirini. This belongs to the series of data relating to Natural Hazards which includes the following groups - coastal erosion, coastal inundation, inland flooding, and land subsidence. This layer belongs to the inland flooding group. Use in conjunction with High Risk Flood Area, Flood Plain Management Area,and Defended Area.

Waikato District Council - Proposed District Plan (Decisions version), Notified 17 January 2022. This layer is a spatial representation of an overlay in the Proposed District Plan and indicates where land use will be regulated by various associated rules. It will be used as a guide in the regulatory process of implementing the Proposed District Plan and managing land use, subdivision, the environment and economy. This dataset is subject to changes undertaken through the Resource Management Act. Note individual Proposed Plan rules can have different statuses, some may have current legal effect and others will not until the Proposed Plan becomes operative. This data is provided for use in the District Plan only.

River Flood Hazard Zones (100 year CC Extent): The area potentially susceptible to river flooding in a 1% AEP / 100Yr ARI + CC (climate change).River flood hazard zones were developed by 2 different external expert consultants between 2016 (Priority Rivers) and 2021 (Regionwide Models). The layers are derived by advanced models using empirical calculations.

Two different models were used to construct the river flood layers: TUFLOW (Water Technology, 2021), InfoWorks (URS, 2016). The reports detailing the methodologies, and risk assessment on the Priority Rivers, can be accessed from the NRC website.

This layer contains the index tiles for LiDAR data for the Nelson - Tasman region, captured between 23 August 2022 and 6 September 2022.

• The DEM is available as layer Nelson and Tasman - Top of the South Flood LiDAR 1m DEM (2022).

• The DSM is available as layer Nelson and Tasman - Top of the South Flood LiDAR 1m DSM (2022.

• The LAS point cloud and vendor project reports are available from OpenTopography.

LiDAR was captured for Nelson City Council, Tasman District Council, Waka Kotahi NZ Transport Agency and the National Emergency Management Agency by Aerial Surveys Ltd between 23 August 2022 and 6 September 2022. These datasets were generated by Arial Surveys Ltd and their subcontractors. Data management and distribution is by Toitū Te Whenua Land Information New Zealand. Coverage includes Nelson to Brightwater, including the Waimea River, State Highway 6 from Hira to Rai Valley and Ōkiwi Bay access road, plus Abel Tasman Drive, Bird Hill and Takaka Hill in Golden Bay.

Data comprises:

• DEM: tif or asc tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout

• DSM: tif or asc tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout

• Point cloud: las tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout

Pulse density specification is at a minimum of 2.8 pulses/square metre.

Vertical Accuracy Specification is +/- 0.2m (95%) Horizontal Accuracy Specification is +/- 1.0m (95%)

Vertical datum is NZVD2016.

Purpose: This data has been published to support the Waikato Regional Hazards Portal. This data is part of the River Flooding theme. The data is a compilation of flood hazard information which is sourced from a combination of; previous event information (photos and aerial imagery, anecdotal information, post-event surveys), flood modelling, flood protection and drainage scheme information, and elevation data. Data is presented as polygons which represent susceptibility to flooding, with attribute information indicating type of flooding, historical floods, data reference and quality, etc. The data attribute also includes "FLOOD_HAZARD_ID", which is an ID number that corresponds to text files with additional information, available internally in Discover folder # 30 07 10. This data should be viewed in conjunction with flood protection and land drainage asset data (datasets with the prefix RACS, many of these layers are publically available from the CoLAB- Waikato Data Portal). This is for general public information on susceptibility to flooding in the Waikato Region, and should be used to indicate where further investigation may be required. It is important to note that this information is not suitable to use for building or resource consent applications as it is not suitable to be viewed at a property scale.Intended Use Scale: Data should not be used at scales greater than 1:50,000.Data Use Limits: Any flood events which have occurred since the last date of verification (2019) will not be recorded in this data.Data Specific Disclaimers: "The presence of a hazard zone on this map 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, while providing the information in good faith, accepts no responsibility for any loss, damage, injury, or loss in value of any person, property, service or otherwise resulting from hazards or knowledge of hazards in the Waikato Region.” “The information portrayed on this map is to be used for emergency management and/or evacuation purposes only and is not to be used for land use planning.” “The information contained in this data set and/or map is correct at the date of verification only. Date of verification is 1 June 2006.” “The data provided shall not to be viewed, used or reproduced at a scale closer than 1:50,000 and is not to be viewed, used or reproduced with other datasets of differing accuracy (e.g. cadastral information). This condition recognises the accuracy of the dataset and the consequential lack of applicability to property specific decision making”. 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.”WRC Metadata: For full metadata see HAZARD.sdeadmin.HAZ_REGIONAL_FLOOD_HAZARD - 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.

Made available for NPDC GeoHUB (GIS Hub Site and Open Data Portal) :A full description is available in the Metadata. SeeTerms of Use.Notes:The "Updated" date, noted here in the item, does not accurately reflect the currency of the data within the Feature Layer.The data available for download on NPDC GeoHUB is updated daily, this results in differences between what is available online and NPDC's databases.

Layer used in public web app https://niwa.maps.arcgis.com/apps/webappviewer/index.html?id=933e8f24fe9140f99dfb57173087f27d to provide Flood Estimation for New Zealand 1. Modelled flood frequency estimates on river lines.NZREACH NZ digital network 1 ID no.River name where availableAreakm2 catchment area draining to the downstream end of this reach (square kilometres)q100_reach ratio of Q100 (1% aep flood) to mean annual floodH&C18_MAF mean annual flood (cumecs)H&C18_5-yr 5-yr (20% aep) flood (cumecs)H&C18_10y 10-yr (10% aep) flood (cumecs)H&C18_20y 20-yr (5% aep) flood (cumecs)H&C18_50y 50-yr (2% aep) flood (cumecs)H&C18_100y 100-yr (1% aep) flood (cumecs)H&C18_1000y 1000-yr (0.1% aep) flood (cumecs)HCse_MAF standard error of mean annual flood (cumecs)HCse_5y standard error of 5-yr (20% aep) flood (cumecs)HCse_10y standard error of 10-yr (10% aep) flood (cumecs) HCse_20y standard error of 20-yr (5% aep) flood (cumecs)HCse_50y standard error of 50-yr (2% aep) flood (cumecs)HCse_100y standard error of 100-yr (1% aep) flood (cumecs)HCse_1000y standard error of 1000-yr (0.1% aep) flood (cumecs)Strm_Order Strahler stream order (1=headwater, two ones join to make an order 2, etc.) 2. 2. At-site flood statistics at flow recorders used in the model development Siteno NIWA reference number for flow recorder Name Flow recorder name generally 'river' at 'location' NZTM_E NZTM easting NZTM_N NZTM northingRegion Regional council or unitary authority territoryOperator Organisation that oprates the flow recorder Funder Organisation that funds the flow recorder (can be more than one)Area_km2 catchment area draining to the flow recorder (square kilometers)No_years Number of years in the annual flood series (allowing for years with missing data)L1_mean Mean of the annual flood series (linear moment 1)L2 Linear moment 2 of the annual flood series (analogous to standard deviation)Lcv Linear CV of the annual flood series (L2/L1) T3_Lskew Linear skew ratio of the annual flood series T4_Lkurt Linear kurtosis ratio of the annual flood series Gumb_u Gumbel distribution u of the annual flood series Gumb_alpha Gumbel distribution alpha of the annual flood series GEV_u Generalised Extreme Value u of the annual flood seriesGEV_alpha Generalised Extreme Value alpha of the annual flood series GEV_k Generalised Extreme Value k of the annual flood series GEV_z Hosking-Wallis normal standard variate to test significance of GEV-k (is the at-site distribution Gumbel or not?)Data 2.33y mean annual flood (2.33-yr assuming Gumbel, or 43% aep)Data 5y 5-yr (20% aep) flood (cumecs)Data 10y 10-yr (10% aep) flood (cumecs)Data 20y 20-yr (5% aep) flood (cumecs)Data 50y 50-yr (2% aep) flood (cumecs)Data 100y 100-yr (1% aep) flood (cumecs)Data 250y 250-yr (0.4% aep) flood (cumecs)Data 500y 500-yr (0.2% aep) flood (cumecs) Data 1000y 1000-yr (0.1% aep) flood (cumecs)se_2.33y standard error of mean annual flood (%) se_5y standard error of 5-yr (20% aep) flood (%)se_10y standard error of 10-yr (10% aep) flood (%)se_20y standard error of 20-yr (5% aep) flood (%)se_50y standard error of 50-yr (2% aep) flood (%)se_100y standard error of 100-yr (1% aep) flood (%)se_250y standard error of 250-yr (0.4% aep) flood (%)se_500y standard error of 500-yr (0.2% aep) flood (%) se_1000y standard error of 1000-yr (0.1% aep) flood (%)

Layer used in public web app https://niwa.maps.arcgis.com/apps/webappviewer/index.html?id=933e8f24fe9140f99dfb57173087f27d to provide Flood Estimation for New Zealand 1. Modelled flood frequency estimates on river lines.NZREACH NZ digital network 1 ID no.River name where availableAreakm2 catchment area draining to the downstream end of this reach (square kilometres)q100_reach ratio of Q100 (1% aep flood) to mean annual floodH&C18_MAF mean annual flood (cumecs)H&C18_5-yr 5-yr (20% aep) flood (cumecs)H&C18_10y 10-yr (10% aep) flood (cumecs)H&C18_20y 20-yr (5% aep) flood (cumecs)H&C18_50y 50-yr (2% aep) flood (cumecs)H&C18_100y 100-yr (1% aep) flood (cumecs)H&C18_1000y 1000-yr (0.1% aep) flood (cumecs)HCse_MAF standard error of mean annual flood (cumecs)HCse_5y standard error of 5-yr (20% aep) flood (cumecs)HCse_10y standard error of 10-yr (10% aep) flood (cumecs) HCse_20y standard error of 20-yr (5% aep) flood (cumecs)HCse_50y standard error of 50-yr (2% aep) flood (cumecs)HCse_100y standard error of 100-yr (1% aep) flood (cumecs)HCse_1000y standard error of 1000-yr (0.1% aep) flood (cumecs)Strm_Order Strahler stream order (1=headwater, two ones join to make an order 2, etc.) 2. 2. At-site flood statistics at flow recorders used in the model development Siteno NIWA reference number for flow recorder Name Flow recorder name generally 'river' at 'location' NZTM_E NZTM easting NZTM_N NZTM northingRegion Regional council or unitary authority territoryOperator Organisation that oprates the flow recorder Funder Organisation that funds the flow recorder (can be more than one)Area_km2 catchment area draining to the flow recorder (square kilometers)No_years Number of years in the annual flood series (allowing for years with missing data)L1_mean Mean of the annual flood series (linear moment 1)L2 Linear moment 2 of the annual flood series (analogous to standard deviation)Lcv Linear CV of the annual flood series (L2/L1) T3_Lskew Linear skew ratio of the annual flood series T4_Lkurt Linear kurtosis ratio of the annual flood series Gumb_u Gumbel distribution u of the annual flood series Gumb_alpha Gumbel distribution alpha of the annual flood series GEV_u Generalised Extreme Value u of the annual flood seriesGEV_alpha Generalised Extreme Value alpha of the annual flood series GEV_k Generalised Extreme Value k of the annual flood series GEV_z Hosking-Wallis normal standard variate to test significance of GEV-k (is the at-site distribution Gumbel or not?)Data 2.33y mean annual flood (2.33-yr assuming Gumbel, or 43% aep)Data 5y 5-yr (20% aep) flood (cumecs)Data 10y 10-yr (10% aep) flood (cumecs)Data 20y 20-yr (5% aep) flood (cumecs)Data 50y 50-yr (2% aep) flood (cumecs)Data 100y 100-yr (1% aep) flood (cumecs)Data 250y 250-yr (0.4% aep) flood (cumecs)Data 500y 500-yr (0.2% aep) flood (cumecs) Data 1000y 1000-yr (0.1% aep) flood (cumecs)se_2.33y standard error of mean annual flood (%) se_5y standard error of 5-yr (20% aep) flood (%)se_10y standard error of 10-yr (10% aep) flood (%)se_20y standard error of 20-yr (5% aep) flood (%)se_50y standard error of 50-yr (2% aep) flood (%)se_100y standard error of 100-yr (1% aep) flood (%)se_250y standard error of 250-yr (0.4% aep) flood (%)se_500y standard error of 500-yr (0.2% aep) flood (%) se_1000y standard error of 1000-yr (0.1% aep) flood (%) Return period estimates of the area-rain intensity values for small catchments. Where results display '-1' the catchment is greater than 30 square kilometres and no answer is available. Numbers need to be multiplied by the Rational Method 'C' factor to give the required flood magnitude. NZREACH NZ digital network 1 ID no. AREA_km2 catchment area draining to the flow recorder (square kilometers)QIA_5y 5-yr (20% aep) IA estimateQIA_10y 10-yr (10% aep) IA estimate QIA_20y 20-yr (5% aep) IA estimateQIA_50y 50-yr (2% aep) IA estimateQIA_100y 100-yr (1% aep) IA estimate QIA_1000y 1000-yr (0.1% aep) IA estimate4. Annual data values at flow recorders used in the model development. Layer coming later.Spatial Reference: New Zealand Transverse Mercator (NZTM) EPSG:2193 (2193) XMin: 1090154.6277 YMin: 4748852.6367 XMax: 2089112.8753000004 YMax: 6193369.0554_Item Page Created: 2019-03-15 05:14 Item Page Last Modified: 2019-10-07 01:39Owner: sykesjr_NIWA

Waikato District Council - Proposed District Plan (Stage 2 Natural Hazards), Notified 27 July 2020. This layer is a spatial representation of an overlay in the Proposed District Plan and indicates where land use will be regulated by various associated rules. It will be used as a guide in the regulatory process of implementing the Proposed District Plan and managing land use, subdivision, the environment and economy. This dataset is subject to changes undertaken through the Resource Management act.Note individual Proposed Plan rules can have different statuses, some may have current legal effect and others will not until the Proposed Plan becomes operative. This data is provided for use in the District Plan only.

The Flood Plain Management Area is the floodplain in a 1% Annual Exceedance Probability (AEP) flood event. This belongs to the series of data relating to Natural Hazards which includes the following groups - coastal erosion, coastal inundation, inland flooding, and land subsidence. This layer belongs to the inland flooding group. Use in conjunction with High Risk Flood Area, Flood Ponding Area,and Defended Area.

Index Tiles ONLY, for actual orthophotos see layer Westport Flood 0.125m Urban Aerial Photos (2021)

The aerial photography for this project was captured in July 2021 to record flood damage.

Orthophotography within the West Coast Region captured in the flying season of 2020-2021.

Imagery was captured for Toitū Te Whenua Land Information New Zealand by Aerial Surveys Ltd, Unit A1, 8 Saturn Place, Albany 0632, New Zealand.

Data comprises: • 105 ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:1000 tile layout. • Tile layout in NZTM projection containing relevant information.

The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection.

Imagery supplied as 12.5cm pixel resolution (0.125m GSD), 3-band (RGB) uncompressed GeoTIFF. The final spatial accuracy is ±0.25 at 95% confidence level in clear flat areas.

Also available on: • Basemaps • NZ Imagery - Registry of Open Data on AWS

This layer contains the DEM for LiDAR data in Gisborne and Hawke's Bay following Cyclone Gabrielle, captured from 26 February to 15 March 2023.

• The DSM is available as layer Gisborne and Hawke's Bay - Cyclone Gabrielle Post Flood LiDAR 1m DSM (2023)

• The Index Tiles are available as layer Gisborne and Hawke's Bay - Cyclone Gabrielle Post Flood LiDAR Index Tiles (2023)

LiDAR was captured for NIWA and the New Zealand Government by University of Canterbury and Christchurch Helicopters from 26 February to 15 March 2023. Coverage includes Aropaoanui River, Esk Valley, Heretaunga Plains (Ngaruroro and Tutaekuri Rivers), Mangahauini River (Tokomaru Bay), Tangoio (Te Ngarue Stream), Tukituki River, Uawa River (Tolaga Bay), Waipaoa River and Wairoa River. Data management and distribution is by Toitū Te Whenua Land Information New Zealand.

Data contacts: University of Canterbury - James Brassington and Justin Stout NIWA - Hamish Biggs, Emily Lane and Andrew Tait

Data comprises:

• DEM: tif or asc tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout.

• DSM: tif or asc tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout

Vertical datum is NZVD2016.

A map service and web application where users can extract flood statistics from a regional flood model, at-site flood statistics and annual maximum flows from flow recorders used in the model development, flood estimates based on rain intensity for use in the Rational Method. 1. Modelled flood frequency estimates on river lines.NZREACH NZ digital network 1 ID no.River name where availableAreakm2 catchment area draining to the downstream end of this reach (square kilometres)q100_reach ratio of Q100 (1% aep flood) to mean annual floodH&C18_MAF mean annual flood (cumecs)H&C18_5-yr 5-yr (20% aep) flood (cumecs)H&C18_10y 10-yr (10% aep) flood (cumecs)H&C18_20y 20-yr (5% aep) flood (cumecs)H&C18_50y 50-yr (2% aep) flood (cumecs)H&C18_100y 100-yr (1% aep) flood (cumecs)H&C18_1000y 1000-yr (0.1% aep) flood (cumecs)HCse_MAF standard error of mean annual flood (cumecs)HCse_5y standard error of 5-yr (20% aep) flood (cumecs)HCse_10y standard error of 10-yr (10% aep) flood (cumecs) HCse_20y standard error of 20-yr (5% aep) flood (cumecs)HCse_50y standard error of 50-yr (2% aep) flood (cumecs)HCse_100y standard error of 100-yr (1% aep) flood (cumecs)HCse_1000y standard error of 1000-yr (0.1% aep) flood (cumecs)Strm_Order Strahler stream order (1=headwater, two ones join to make an order 2, etc.) 2. 2. At-site flood statistics at flow recorders used in the model development

Siteno NIWA reference number for flow recorder Name Flow recorder name generally 'river' at 'location' NZTM_E NZTM easting NZTM_N NZTM northingRegion Regional council or unitary authority territoryOperator Organisation that oprates the flow recorder Funder Organisation that funds the flow recorder (can be more than one)Area_km2 catchment area draining to the flow recorder (square kilometers)No_years Number of years in the annual flood series (allowing for years with missing data)L1_mean Mean of the annual flood series (linear moment 1)L2 Linear moment 2 of the annual flood series (analogous to standard deviation)Lcv Linear CV of the annual flood series (L2/L1) T3_Lskew Linear skew ratio of the annual flood series T4_Lkurt Linear kurtosis ratio of the annual flood series Gumb_u Gumbel distribution u of the annual flood series Gumb_alpha Gumbel distribution alpha of the annual flood series GEV_u Generalised Extreme Value u of the annual flood seriesGEV_alpha Generalised Extreme Value alpha of the annual flood series GEV_k Generalised Extreme Value k of the annual flood series GEV_z Hosking-Wallis normal standard variate to test significance of GEV-k (is the at-site distribution Gumbel or not?)Data 2.33y mean annual flood (2.33-yr assuming Gumbel, or 43% aep)Data 5y 5-yr (20% aep) flood (cumecs)Data 10y 10-yr (10% aep) flood (cumecs)Data 20y 20-yr (5% aep) flood (cumecs)Data 50y 50-yr (2% aep) flood (cumecs)Data 100y 100-yr (1% aep) flood (cumecs)Data 250y 250-yr (0.4% aep) flood (cumecs)Data 500y 500-yr (0.2% aep) flood (cumecs) Data 1000y 1000-yr (0.1% aep) flood (cumecs)se_2.33y standard error of mean annual flood (%) se_5y standard error of 5-yr (20% aep) flood (%)se_10y standard error of 10-yr (10% aep) flood (%)se_20y standard error of 20-yr (5% aep) flood (%)se_50y standard error of 50-yr (2% aep) flood (%)se_100y standard error of 100-yr (1% aep) flood (%)se_250y standard error of 250-yr (0.4% aep) flood (%)se_500y standard error of 500-yr (0.2% aep) flood (%) se_1000y standard error of 1000-yr (0.1% aep) flood (%)

1. Return period estimates of the area-rain intensity values for small catchments. Where results display '-1' the catchment is greater than 30 square kilometres and no answer is available. Numbers need to be multiplied by the Rational Method 'C' factor to give the required flood magnitude. NZREACH NZ digital network 1 ID no. AREA_km2 catchment area draining to the flow recorder (square kilometers)QIA_5y 5-yr (20% aep) IA estimateQIA_10y 10-yr (10% aep) IA estimate QIA_20y 20-yr (5% aep) IA estimateQIA_50y 50-yr (2% aep) IA estimateQIA_100y 100-yr (1% aep) IA estimate QIA_1000y 1000-yr (0.1% aep) IA estimate4. Annual data values at flow recorders used in the model development. Layer coming later.

_Item Page Created: 2018-07-08 23:41 Item Page Last Modified: 2025-02-08 19:25Owner: NIWA_OpenData

Abstract: The Coastal Inundation dataset maps the extent of sea water coverage expected around the coastal areas of the Auckland Region during storm events. It replaces the existing inundation extent currently (July 2018) published on Geomaps. The new data published has been derived from analysis carried out by NIWA in 2016/2017.A description of the derivation of the data is here: U:\COO\IES\STW\SW CAMP\Flood Planning Team\Coastal Inundation Analysis\DELIVERY FILES 2017\Stage III\Onde Drive Folder\CoastalInundation\MemoDeliveryReport_Final.pdfLineage: The flood levels derived by NIWA in the report Coastal Inundation by Storm Tides and Waves in the Auckland Region. June 2016. Technical Report 2016/2017 (Part 2)were used to establish the inundation water levels expected around the region. These levels were projected onto the land topography to establish the extent of coastal flooding.The land topography was derived from the 2013 LiDAR survey or 2006 LiDAR survey. The additional analysis of the Parakai Harbour area (described in Part 3 of the above report) was not published, as a higher density of LiDAR land topography is expected to be available in 2018, which will improve the accuracy in this area when it becomes available.Update Cycle: Adhoc when improved data becomes available.This data is available to the public on the Geomaps viewer and is copied into LIMs

Flood_Statistics_2018_REC1

This dataset (view) contains the current risk ratings for rail structures (bridges) across NZ. The dataset is used to prioritise maintenance, renewal of assets and other risk mitigation such as flood protection. The source of data is KiwiRail's Maximo asset management system. The data is shared publicly and can be used for planning purposes - such as lifelines and emergency management.