Groundwater is the water that soaks into the ground from rain and can be stored beneath the ground. Groundwater floods occur when the water stored beneath the ground rises above the land surface. The Historic Groundwater Flood Map shows the observed peak flood extents caused by groundwater in Ireland. This map was made using satellite images (Copernicus Programme Sentinel-1), field data, aerial photos, as well as flood records from the past. Most of the data was collected during the flood events of winter 2015 / 2016, as in most areas this data showed the largest floods on record.This map is to the scale 1:20,000. This means it should be viewed at that scale. When printed at that scale 1cm on the map relates to a distance of 200m.The map is a vector dataset. Vector data portray the world using points, lines, and polygons (area). The floods are shown as polygons. Each polygon has info about the type of flood, the data source, and the area of the flood.The flood extents were calculated using data and techniques with various precision levels, and as such, it may not show the true historic peak flood extents.The Winter 2015/2016 Surface Water Flooding map shows fluvial (rivers) and pluvial (rain) floods, excluding urban areas, during the winter 2015/2016 flood event, and was developed as a by-product of the historic groundwater flood map.This map is to the scale 1:20,000. This means it should be viewed at that scale. When printed at that scale 1cm on the map relates to a distance of 200m.The map is a vector dataset. The floods are shown as polygons. Each polygon has info about the type of flood, the data source, and the area of the flood.The flood extents were made using remote sensing images (Copernicus Programme Sentinel-1), which covered any site in Ireland every 4-6 days. As such, it may not show the true peak flood extents.The Synthetic Aperture Radar (SAR) Seasonal Flood Maps shows observed peak flood extents which took place between Autumn 2015 and Summer 2021. The maps were made using Synthetic Aperture Radar (SAR) images from the Copernicus Programme Sentinel-1 satellites. SAR systems emit radar pulses and record the return signal at the satellite. Flat surfaces such as water return a low signal. Based on this low signal, SAR imagery can be classified into non-flooded and flooded (i.e. flat) pixels.Flood extents were created using Python 2.7 algorithms developed by Geological Survey Ireland. They were refined using a series of post processing filters. Please read the lineage for more information.The flood maps shows flood extents which have been observed to occur. A lack of flooding in any part of the map only implies that a flood was not observed. It does not imply that a flood cannot occur in that location at present or in the future.This flood extent are to the scale 1:20,000. This means they should be viewed at that scale. When printed at that scale 1cm on the maps relates to a distance of 200m.They are vector datasets. Vector data portray the world using points, lines, and polygons (areas). The flood extents are shown as polygons. Each polygon has information on the confidence of the flood extent (high, medium or low), a flood id and a unique id.The Groundwater Flooding High Probability map shows the expected flood extent of groundwater flooding in limestone regions for annual exceedance probabilities (AEP’s) of 10%, which correspond with a return period of every 10 years. The map was created using groundwater levels measured in the field, satellite images and hydrological models.This map is to the scale 1:20,000. This means it should be viewed at that scale. When printed at that scale 1cm on the map relates to a distance of 200m.The map is a vector dataset. The floods are shown as polygons. Each polygon has info on the data source, and the area of the flood.The flood extents were calculated using remote sensing data and hydrological modelling techniques with various precision levels. As such, it should be used with caution.The Groundwater Flooding Medium Probability map shows the expected flood extent of groundwater flooding in limestone regions for annual exceedance probabilities (AEP’s) of 1%, which correspond with a return period of every 100 years. The map was created using groundwater levels measured in the field, satellite images and hydrological models.This map is to the scale 1:20,000. This means it should be viewed at that scale. When printed at that scale 1cm on the map relates to a distance of 200m.The map is a vector dataset. The floods are shown as polygons. Each polygon has info on the data source, and the area of the flood.The flood extents were calculated using remote sensing data and hydrological modelling techniques with various precision levels. As such, it should be used with caution.The Groundwater Flooding Low Probability map shows the expected flood extent of groundwater flooding in limestone regions for annual exceedance probabilities (AEP’s) of 0.1%, which correspond with a return period of every 1000 years.The map was created using groundwater levels measured in the field, satellite images and hydrological models.This map is to the scale 1:20,000. This means it should be viewed at that scale. When printed at that scale 1cm on the map relates to a distance of 200m.The map is a vector dataset. Vector data portray the world using points, lines, and polygons (area). The floods are shown as polygons. Each polygon has info on the data source, and the area of the flood.The flood extents were calculated using remote sensing data and hydrological modelling techniques with various precision levels. As such, it should be used with caution.

The Flood Map for Planning Service includes several layers of information. This includes the Flood Zones data which shows the extent of land at present day risk of flooding from rivers and the sea, ignoring the benefits of defences, for the following scenarios:

• Flood Zone 1 – Land having a less than 0.1% (1 in 1000) annual probability of flooding. • Flood Zone 2 – Land having between 0.1% - 1% (1 in 100 to 1 in 1000) annual probability of flooding from rivers or between 0.1% - 0.5% (1 in 200 to 1 in 1000) annual probability of flooding from the sea, and accepted recorded flood outlines . • Flood Zone 3 – Areas shown to be at a 1% (1 in 100) or greater annual probability of flooding from rivers or 0.5% (1 in 200) or greater annual probability of flooding from the sea.

Flood Zone 1 is not shown in this dataset, but covers all areas not contained within Flood Zones 2 and 3. Local Planning Authorities (LPAs) use the Flood Zones to determine if they must consult the Environment Agency on planning applications. They are also used to determine if development is incompatible and whether development is subject to the exception test. The Flood Zones are one of several flood risk datasets used to determine the need for planning applications to be supported by a Flood Risk Assessment (FRA) and subject to the sequential test.

The Flood Zones are a composite dataset including national and local modelled data, and information from past floods.

The Flood Zones are designed to only give an indication of flood risk to an area of land and are not suitable for showing whether an individual property is at risk of flooding. This is because we cannot know all the details about each property.

Users of these datasets should always check they are suitable for the intended use

This hosted feature layer has been published in RI State Plane Feet NAD 83.Statewide flood hazard areas compiled from county-based Digital Flood Insurance Rate Map (DFIRM) databases for Rhode Island. The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. TheDFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA), and in this case redistributed by the Rhode Island Geographic Information System (RIGIS) at the request of the Rhode Island Emergency Management Agency.This dataset provides the user with information on the flood risk hazard zones throughout the state of Rhode Island. Note: the above summary is a slightly modified version adapted from source metadata records provided by FEMA. To provide the user with information on the statewide flood risk based on information provided by the Federal Emergency Management Agency (FEMA) in the DFIRM databases created specifically for the five counties of Rhode Island (Bristol, Kent, Newport, Providence, and Washington). This dataset provides information on the likelihood that a flood may occur at a given location in the state. The files and information used to create this dataset were originally provided to the Rhode Island Emergency Management Agency (RIEMA) by FEMA.This information was in the form of DFIRM databases for each of the five RI counties. This information was then redistributed by RIGIS at the request of RIEMA. The information provided by this data is only a subset of the information available in the original DFIRM databases located on the RIGIS website. For a specific county's complete DFIRM database, please visit the RIGIS website and download the appropriate DFIRM database. This metadata record is specific to this dataset and only contains information relevant to this dataset as provided by FEMA the original DFIRM metadata records. These can be found and referenced in the /DOCUMENT folder that is downloaded as part of a DFIRM package for a specific Rhode Island county. Another valuable source of documentation is FEMA's "Guidelines and Specifications for Flood Hazard Mapping Partners". It is currently available online at https://www.fema.gov/guidelines-and-standards-flood-risk-analysis-and-mapping. The Guide offers a tremendous amount of information regarding how DFIRM data are created, and detailed information about the individual files that constitute a DFIRM database.

The Flood Map for Planning (Rivers and Sea) includes several layers of information. This dataset covers Flood Zone 2 and should not be used without Flood Zone 3. It is our best estimate of the areas of land at risk of flooding, when the presence of flood defences are ignored and covers land between Zone 3 and the extent of the flooding from rivers or the sea with a 1 in 1000 (0.1%) chance of flooding each year. This dataset also includes those areas defined in Flood Zone 3.This dataset is designed to support flood risk assessments in line with Planning Practice Guidance ; and raise awareness of the likelihood of flooding to encourage people living and working in areas prone to flooding to find out more and take appropriate action.The information provided is largely based on modelled data and is therefore indicative rather than specific. Locations may also be at risk from other sources of flooding, such as high groundwater levels, overland run off from heavy rain, or failure of infrastructure such as sewers and storm drains.The information indicates the flood risk to areas of land and is not sufficiently detailed to show whether an individual property is at risk of flooding, therefore properties may not always face the same chance of flooding as the areas that surround them. This is because we do not hold details about properties and their floor levels. Information on flood depth, speed or volume of flow is not included.NOTE: We have paused quarterly updates of this dataset. Please visit the “Pause to Updates of Flood Risk Maps” announcement on our support pages for further information. We will provide notifications on the Flood Map for Planning website to indicate where we have new flood risk information. Other data related to the Flood Map for Planning will continue to be updated, including data relating to flood history, flood defences, and water storage areas.Defra Network WMS server provided by the Environment Agency

PLEASE NOTE: This dataset has been retired. It has been superseded by https://environment.data.gov.uk/dataset/04532375-a198-476e-985e-0579a0a11b47. Links to this data will be removed after April 2025. We encourage users to download this Flood Zones dataset if you would like to retain a comparison ability beyond this date.

The Flood Map for Planning (Rivers and Sea) includes several layers of information. This dataset covers Flood Zone 2 and should not be used without Flood Zone 3. It is our best estimate of the areas of land at risk of flooding, when the presence of flood defences are ignored and covers land between Zone 3 and the extent of the flooding from rivers or the sea with a 1 in 1000 (0.1%) chance of flooding each year. This dataset also includes those areas defined in Flood Zone 3.

This dataset is designed to support flood risk assessments in line with Planning Practice Guidance ; and raise awareness of the likelihood of flooding to encourage people living and working in areas prone to flooding to find out more and take appropriate action.

The information provided is largely based on modelled data and is therefore indicative rather than specific. Locations may also be at risk from other sources of flooding, such as high groundwater levels, overland run off from heavy rain, or failure of infrastructure such as sewers and storm drains.

The information indicates the flood risk to areas of land and is not sufficiently detailed to show whether an individual property is at risk of flooding, therefore properties may not always face the same chance of flooding as the areas that surround them. This is because we do not hold details about properties and their floor levels. Information on flood depth, speed or volume of flow is not included.

PLEASE NOTE: This dataset has been retired. It has been superseded by https://environment.data.gov.uk/dataset/04532375-a198-476e-985e-0579a0a11b47. Links to this data will be removed after April 2025. We encourage users to download this Flood Zones dataset if you would like to retain a comparison ability beyond this date.

The Flood Map for Planning (Rivers and Sea) includes several layers of information. This dataset covers Flood Zone 3. It is our best estimate of the areas of land at risk of flooding, when the presence of flood defences are ignored and covers land with a 1 in 100 (1%) or greater chance of flooding each year from Rivers; or with a 1 in 200 (0.5%) or greater chance of flooding each year from the Sea.

This dataset is designed to support flood risk assessments in line with Planning Practice Guidance; and raise awareness of the likelihood of flooding to encourage people living and working in areas prone to flooding to find out more and take appropriate action.

The information provided is largely based on modelled data and is therefore indicative rather than specific.

Locations may also be at risk from other sources of flooding, such as high groundwater levels, overland run off from heavy rain, or failure of infrastructure such as sewers and storm drains.

The information indicates the flood risk to areas of land and is not sufficiently detailed to show whether an individual property is at risk of flooding, therefore properties may not always face the same chance of flooding as the areas that surround them. This is because we do not hold details about properties and their floor levels.

Information on flood depth, speed or volume of flow is not included.

The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision (LOMRs) that have been issued against those databases since their publication date. The DFIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper Flood Insurance Rate Maps(FIRMs). The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The NFHL data are derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). The specifications for the horizontal control of DFIRM data are consistent with those required for mapping at a scale of 1:12,000. The NFHL data contain layers in the Standard DFIRM datasets except for S_Label_Pt and S_Label_Ld. The NFHL is available as State or US Territory data sets. Each State or Territory data set consists of all DFIRMs and corresponding LOMRs available on the publication date of the data set.

Flood zones are a guide produced by the Environment Agency to demonstrate the probability of river and sea flooding in areas across England. Flood zones are based on the likelihood of an area flooding, with flood zone 1 areas least likely to flood and flood zone 3 areas more likely to flood. The flood zones were produced to help developers, councils and communities understand the flood risks present in specific locations or regions. Despite being a very useful indicator of an area’s flood risk, the zones cannot tell you whether a location will definitely flood or to what severity.

Bitly Link for this page: https://bit.ly/mvcfloodcompareAll datasets presented here are compiled by organizations other than the Martha's Vineyard Commission (MVC). The MVC has simply pulled these datasets into one map viewer for ease of direct visual comparison. The MVC encourages the viewer of this map to do their due diligence and research to understand the wide array of methodologies used to model flood inundation and sea level rise.The 3 Flood Inundation datasets presented are: FEMA (100 year or 1% annual probability flood zone) as per Effective Year 2016 data release.Mass Coast - Coastal Flood Risk Model (presented as flood probability for 3 future time horizons)Storm Tide Pathways - Flood Inundation Extents based on Total Water Level (in feet) relative to MLLW. There's a separate data layer for each inundation plane in half foot increments from 2.5ft MLLW to 19.5ft MLLW.SLOSH - Hurricane Inundation - Worst Case ScenarioVarious Links to learn more about these datasets:FEMA 2016 Data for Dukes CountyCoastal Zone Management Viewer: Mass Coast - Coastal Flood Risk Model Mass Coast 2030 Flood RiskMass Coast 2050 Flood RiskMass Coast 2070 Flood RiskMass Coast FAQStorm Tide Pathways App and Storm Tide Pathways InfoSLOSH - produced by NOAA & NWS v3 June 2022 (high tide scenario)The legend for the Mass Coast (MC-FRM) data shows the:The Probabilities 0.1% (in coral color) to 100% (in dark blue) is the Probability of Inundation - which is the chance of becoming flooded at some point each year.Coast Flood Exceedance Probabilities shown in the legend display the modeled outputs ranging from 0.1% (0.001, otherwise known as the 1,000-year storm) to 100% (1.0), which corresponds to the one-year storm. -- The 100% probability level generally corresponds to the annual high water value (NOT the average high tide).

Other data on this map include Salt Marshes, Wetlands MassDEP, Wetland Migration SLAMM Model (year 2070 with high sea level rise), Parcel Lines, and Building Roofprints.

The New Jersey Flood Risk Notification Tool Map contains the GIS layers to determine potential flood risk for parcels in New Jersey. This map was developed for use in the New Jersey Flood Risk Notification Tool which can be viewed by clicking here.The Flood Risk Notice and property condition disclosure form requires you to disclose if the property is in the Special Flood Hazard Area (100-year or 1% annual chance floodplain) or the Moderate Flood Hazard Area (500-year or 1% annual chance floodplain). You will need to disclose all FEMA Flood Zones that overlap your property. There may be more than one, or there may be none. This includes any flood zones mapped according to preliminary maps. FEMA periodically re-assesses a community’s flood risk using updated data and modeling and mapping technology. These updated models are published as preliminary maps until they are made effective following a public comment or appeal period.The absence of flood indicators does not mean that a property is free from flood risk. Flooding can occur anywhere. The geographic extent of flood-prone areas can change due to local factors including increases in impervious surface; changes to stream flow; natural impediments; or aging, poorly maintained, or failing infrastructure. The size and extent of flood prone areas are also expanding due to climate change-related impacts like increasing rainfall intensities and sea-level rise.This tool does not provide information regarding the applicability of any NJDEP regulations. The absence of flood indicators does not mean that a property is free from flood risk. Flooding can occur anywhere. The geographic extent of flood-prone areas can change due to local factors including increases in impervious surface; changes to stream flow; natural impediments; or aging, poorly maintained, or failing infrastructure. The size and extent of flood-prone areas are expanding due to climate change-related impacts like increasing rainfall intensities and sea-level rise.

PLEASE NOTE: this dataset has been retired. It has been superseded by data for Flood Risk Areas: https://environment.data.gov.uk/dataset/f3d63ec5-a21a-49fb-803a-0fa0fb7238b6

Set of shapefiles defining Indicative Flood Risk Areas for local risk. Indicative Flood Risk Areas are provided by the Environment Agency for use by Lead Local Flood Authorities in England in their review during 2017 of Preliminary Flood Risk Assessments and Flood Risk Areas under the Flood Risk Regulations.

The Indicative Flood Risk Areas are primarily based on an aggregated 1km square grid Updated Flood Map for Surface Water (1 in 100 and 1000 annual probability rainfall), informally referred to as the “blue square map”. These are 1km grids across England and consist of the following data layers:

• Surface Water Flood Risk Exposure Grid – 1km square grid that shows places above the flood risk threshold defined, using the 1 in 100 and 1000 annual probability (deep) Flood Map for Surface Water. • Flood risk thresholds used to generate the “blue Squares”: - Number of people > 200 - Number of critical services, including electricity and water > 1 - Number of non-residential properties > 20 • Cluster Maps – are aggregations of 3km by 3km squares that each contain at least 5 touching "blue squares" (i.e. 1km grid squares where one of the thresholds above is exceeded) • Communities at Risk by Lead Local Flooding Authority • People Sensitivity Map by Lead Local Flood Authority.

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). The file is georeferenced to earth?s surface using the State Plane coordinate system. The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:12,000.

This dataset consists of raster geotiff outputs from a series of modeling simulations for the California Central Valley. The full methods and results of this research are described in detail in “Integrated modeling of climate, land use, and water availability scenarios and their impacts on managed wetland habitat: A case study from California’s Central Valley” (2021). Land-use and land-cover change for California's Central Valley were modeled using the LUCAS model and five different scenarios were simulated from 2011 to 2101 across the entirety of the valley. The five future scenario projections originated from the four scenarios developed as part of the Central Valley Landscape Conservation Project (http://climate.calcommons.org/cvlcp ). The 4 original scenarios include a Bad-Business-As-Usual (BBAU; high water availability, poor management), California Dreamin’ (DREAM; high water availability, good management), Central Valley Dustbowl (DUST; low water availability, poor management), and Everyone Equally Miserable (EEM; low water availability, good management). These scenarios represent alternative plausible futures, capturing a range of climate variability, land management activities, and habitat restoration goals. We parameterized our models based on close interpretation of these four scenario narratives to best reflect stakeholder interests, adding a baseline Historical Business-As-Usual scenario (HBAU) for comparison. The flood probability raster maps represent the average annual flooding probability of a cell over a specified time period for a specified land use and land cover group and type. Each filename has the associated scenario ID (scn418 = DUST, scn419 = DREAM, scn420 = HBAU, scn421 = BBAU, and scn426 = EEM), flooding probability per pixel per month, over a 30-year period, model iteration (= it0 in all cases as only 1 Monte Carlo simulation was modeled and no iteration data used in the calculation of the probability value), timestep of the 30-year transition summary end date (ts2041 = average annual 30-year transition probability from modeled time steps 2012 to 2041, ts2071 = average annual 30-year flooding probability from modeled timesteps 2042 to 2071, and ts101 = average annual 30-year flooding probability from modeled timesteps 2072 to 2101). The filename will also include one of the 12 monthly flooding designations (e.g. Apr = April; Nov = November). For example, the following filename “scn418_DUST_tgapFLOODING_30yr_Apr_2041.tif” represents 30-year average annual flooding probability for the month of April, for the modeled scenario 418 DUST, over the 2011 to 2041 model period. More information about the LUCAS model can be found here: https://geography.wr.usgs.gov/LUCC/the_lucas_model.php. For more information on the specific parameter settings used in the model contact Tamara S. Wilson (tswilson@usgs.gov)

Flood risk can also change over time because of new building and development, weather patterns and other factors. Although the frequency or severity of impacts cannot be changed, FEMA is working with federal, state, tribal and local partners across the nation to identify flood risk and promote informed planning and development practices to help reduce that risk through the Risk Mapping, Assessment and Planning (Risk MAP) program.

The Flood Map for Planning Service includes several layers of information. This includes the Flood Zones plus climate change data which shows how the combined extent of Flood Zones 2 and 3 could increase with climate change over the next century, ignoring the benefits of any existing flood defences. We have assumed no changes to flood defences or land-use that could occur in future. The effects of climate change on flood risk we may see in the future could be different to those currently considered.

Flood Zones plus climate change should be used to help planners and developers identify the need for: • a site-specific flood risk assessment • the sequential test.

The dataset can also help to inform the preparation of strategic flood risk assessments.

The Flood Zones plus climate change are a composite dataset including national and local modelled data, and information from past floods.

The Flood Zones plus climate change are designed to only give an indication of flood risk to an area of land and are not suitable for showing whether an individual property is at risk of flooding. This is because we cannot know all the details about each property.

Flood Zones plus climate change uses the following climate change allowances: • ‘Central’ allowance for the 2080s epoch (2070-2125) for risk of flooding from rivers • ‘Upper End’ allowance for risk of flooding from the sea, accounting for cumulative sea level rise to 2125.

Users of these datasets should always check they are suitable for the intended use.

From the Flood Risk Non-Regulatory Database that went into effect June 5, 2020. For more information, visit FEMA.gov Flood Maps.Flood Hazard Zones: The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards," Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The DFIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The DFIRM database is a subset of the Digital FIS database that serves to archive the information collected during the FIS.The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). The file is georeferenced to earth's surface using the UTM projection and coordinate system. The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:12,000.Flood Hazard Boundary Line: Boundary line dividing Special Flood Hazard Area Zones and boundary dividing Special Flood Hazard Areas of different Base Flood Elevations, flood Depths or flood velocities.Flood Hazard BFE: Location and attributes for base flood elevations lines shown on DFIRM. This line layer was converted to a polygon by COM GIS department.Flood Hazard Cross Section: Location and attributes for cross-section lines in the area covered by the DFIRM.Flood Hazard Map Index: Location and attributes for DFIRM hardcopy map panels.Use limitationsThe hardcopy FIRM and DFIRM and the accompanying FISs are the official designation of SFHAs and Base Flood Elevations (BFEs) for the NFIP. For the purposes of the NFIP, changes to the flood risk information published by FEMA may only be performed by FEMA and through the mechanisms established in the NFIP regulations (44 CFR Parts 59-78). These digital data are produced in conjunction with the hardcopy FIRMs and generally match the hardcopy map exactly. However the hardcopy flood maps and flood profiles are the authoritative documents for the NFIP. Acknowledgement of FEMA would be appreciated in products derived from these data.

Abstract: This data shows the model nodes, indicating water level only and/or flow and water levels along the centre-line of rivers that have been modelled to generate the CFRAM flood maps. The nodes estimate maximum design event flood flows and maximum flood levels. Flood event probabilities are referred to in terms of a percentage Annual Exceedance Probability, or ‘AEP’. This represents the probability of an event of this, or greater, severity occurring in any given year. These probabilities may also be expressed as odds (e.g. 100 to 1) of the event occurring in any given year. They are also commonly referred to in terms of a return period (e.g. the 100-year flood), although this period is not the length of time that will elapse between two such events occurring, as, although unlikely, two very severe events may occur within a short space of time. The following sets out a range of flood event probabilities for which fluvial and coastal flood maps are typically developed, expressed in terms of Annual Exceedance Probability (AEP), and identifies their parallels under other forms of expression: 10% (High Probability) Annual Exceedance Probability which can also be expressed as the 10 Year Return Period and as a 10:1 odds of occurrence in any given year. 1% (Medium Probability - Fluvail/River Flood Maps) Annual Exceedance Probability which can also be expressed as the 100 Year Return Period and as 100:1 odds of occurrence in any given year. 0.5% (Medium Probability - Coastal Flood Maps) Annual Exceedance Probability which can also be expressed as the 200 Year Return Period and as 200:1 odds of occurrence in any given year. 0.1% (Low Probability) Annual Exceedance Probability which can also be expressed as the 1000 Year Return Period and as 1000:1 odds of occurrence in any given year. The Mid-Range Future Scenario extents where generated taking in in the potential effects of climate change using an increase in rainfall of 20% and sea level rise of 500mm (20 inches). Data has been produced for the 'Areas of Further Assessment' (AFAs), as required by the EU 'Floods' Directive [2007/60/EC] and designated under the Preliminary Flood Risk Assessment, and also for other reaches between the AFAs and down to the sea that are referred to as 'Medium Priority Watercourses' (MPWs). River reaches that have been modelled are indicated by the CFRAM Modelled River Centrelines dataset. Flooding from other reaches of river may occur, but has not been mapped, and so areas that are not shown as being within a flood extent may therefore be at risk of flooding from unmodelled rivers (as well as from other sources). The purpose of the Flood Maps is not to designate individual properties at risk of flooding. They are community-based maps. Lineage: Fluvial and coastal flood map data is developed using hydrodynamic modelling, based on calculated design river flows and extreme sea levels, surveyed channel cross-sections, in-bank / bank-side / coastal structures, Digital Terrain Models, and other relevant datasets (e.g. land use, data on past floods for model calibration, etc.). The process may vary for particular areas or maps. Technical Hydrology and Hydraulics Reports set out full technical details on the derivation of the flood maps. For fluvial flood levels, calibration and verification of the models make use of the best available data, including hydrometric records, photographs, videos, press articles and anecdotal information. Subject to the availability of suitable calibration data, models are verified in so far as possible to target vertical water level accuracies of approximately +/-0.2m for areas within the AFAs, and approximately +/-0.4m along the MPWs. For coastal flood levels, the accuracy of the predicted annual exceedance probability (AEP) of combined tide and surge levels depends on the accuracy of the various components used in deriving these levels i.e. accuracy of the tidal and surge model, the accuracy of the statistical data and the accuracy for the conversion from marine datum to land levelling datum. The output of the water level modelling, combined with the extreme value analysis undertaken as detailed above is generally within +/-0.2m for confidence limits of 95% at the 0.1% AEP. Higher probability (lower return period) events are expected to have tighter confidence limits. v101 (March 2025) The section of map near Oranmore Galway updated following a map review process see https://www.floodinfo.ie/map-review/ for further information, Map Review Code: MR019. v102 (July 2025) The section of map near Claregalway updated following a map review process see https://www.floodinfo.ie/map-review/ for further information, Map Review Code: MR057. Purpose: The data has been developed to comply with the requirements of the European Communities (Assessment and Management of Flood Risks) Regulations 2010 to 2015 (the “Regulations”) (implementing Directive 2007/60/EC) for the purposes of establishing a framework for the assessment and management of flood risks, aiming at the reduction of adverse consequences for human health, the environment, cultural heritage and economic activity associated with floods. .hidden { display: none }

This dataset displays the locations of flood hazard zones identified by FEMA. The Federal Emergency Management Agency (FEMA) produces Flood Insurance Rate maps and identifies Special Flood Hazard Areas as part of the National Flood Insurance Program's floodplain management. Special Flood Hazard Areas have regulations that include the mandatory purchase of flood insurance. This layer is derived from the October 13, 2021 version of the National Flood Hazard Layer feature class S_Fld_Haz_Ar. The data were aggregated into eight classes to produce the Esri Symbology field based on symbology provided by FEMA. All other layer attributes are derived from the National Flood Hazard Layer.The layer was projected to Web Mercator Auxiliary Sphere, then the repair geometry geoprocessing tool was run on it. Its resolution was set to 0.0001 meter. To improve performance Flood Zone values "Area Not Included", "Open Water", "D", "NP", and No Data were removed from the layer. Areas with Flood Zone value "X" subtype "Area of Minimal Flood Hazard" were also removed. An imagery layer created from this dataset provides access to the full set of records in the National Flood Hazard Layer.View Dataset on the Gateway

Risk of Flooding from Surface Water (RoFSW) map is an assessment of where surface water flooding may occur when rainwater does not drain away through the normal drainage systems or soak into the ground, but lies on or flows over the ground instead. It is produced using national scale modelling and enhanced with compatible, locally produced modelling from lead local flood authorities (LLFAs). The RoFSW datasets include information about flooding extents, depths, speed and hazards.

This dataset shows information about flooding extents and depths. The depth of water during a flood is an important factor in how dangerous a flood might be.

RoFSW is a probabilistic product, meaning that it shows the overall risk, rather than the risk associated with a specific event or scenario. In externally published versions of this dataset, risk is displayed as one of three likelihood bandings:

High - greater than or equal to 3.3% (1 in 30) chance in any given year; Medium - less than 3.3% (1 in 30) but greater than or equal to 1% (1 in 100) chance in any given year; Low - less than 1% (1 in 100) but greater than or equal to 0.1% (1 in 1000) chance in any given year.

This dataset shows the likelihood of a flood occurring with water at a given depth (or higher). There are separate layers with thresholds for depths of 0m (i.e. flooding extent), 0.2m, 0.3m, 0.6m, 0.9m, and 1.2m.

NB. This is a complex dataset, with preview available only on certain zoom levels. The Web Mapping service has been set to 1:50 000 in the

These maps have been produced to meet SEPA’s duty to publish flood hazard maps as set out in the Flood Risk Management (Scotland) Act 2009. The maps show where there is a risk of flooding from the sea, from rivers and from surface water.The following probabilities are available for river flooding: - High - 10 year return period - Medium - 200 year return period - Low - 1000 year return period and 200 year return period plus climate change using the UKCP09 high emissions scenario for the 2080s.The river hazard maps show (where available): - Flood extent - Flood depth - Flood velocities where appropriate. The climate change scenario has been defined by United Kingdom Climate Projection 2009 (UKCP09) predictions for 2080 high emissions 95%ile predictions. Medium and low probability flood events were selected for consistency with return periods used in Scottish Planning Policy, whereas the high probability was chosen as it is reflective of observed events experienced over the last few decades.