The Department of Water and Environmental Regulation produces floodplain mapping of rivers and major watercourses and provides floodplain development advice to ensure that proposed floodplain development has adequate flood protection and does not impact on the existing flood regime of the area. This advice is related to major river flooding only. Other issues, such as stormwater drainage and environmental and ecological considerations are not addressed. This dataset contains 10 polygons illustrating the area of land adjacent to a water body which is subject to flooding during a range of possible design events: 1 in 10 (10%) AEP floodplain 1 in 20 (5%) AEP floodplain 1 in 25 (4%) AEP floodplain 1 in 50 (2%) AEP floodplain 1 in 100 (1%) AEP floodplain Designated flood event floodplain 1 in 200 (0.5%) AEP floodplain 1 in 500 (0.2%) AEP floodplain Maximum channel capacity Probable maximum flood Note: To see the full scope of the floodplain mapping, 12 dataset layers are required to be loaded in the following order: FLOODPLAIN DATASET LAYERS: FPM Flood Level Points (m AHD) FPM Flood Level Contours (m AHD) FPM 1 in 100 (1%) AEP Floodway and Flood Fringe Line FPM Extent of Flooding FPM Levee Banks FPM Location of Cross Sections FPM 1 in 100 (1%) AEP Floodplain Development Control Area FPM Map Index FPM Bridges FPM Special Development Condition Area FPM 1 in 100 (1%) AEP Floodway and Flood Fringe Area FPM Floodplain Area The dataset covers the following areas: Avon River - Toodyay to Beverley. Blackwood River – Augusta, Bridgetown, Nannup and Boyup Brook Townsites. Bow River - Bow Bridge Townsite. Capel River - Capel Townsite.

The Department of Water and Environmental Regulation produces floodplain mapping of rivers and major watercourses and provides floodplain development advice to ensure that proposed floodplain …Show full descriptionThe Department of Water and Environmental Regulation produces floodplain mapping of rivers and major watercourses and provides floodplain development advice to ensure that proposed floodplain development has adequate flood protection and does not impact on the existing flood regime of the area. This advice is related to major river flooding only. Other issues, such as stormwater drainage and environmental and ecological considerations are not addressed. Both the floodway and flood fringe make up the 1 in 100 (1%) annual exceedance probability (AEP) floodplain, however there are areas where the floodplain exists, but the floodway and flood fringe does not. In such situations, a different floodplain management strategy applies (for example, the Swan River between the Narrows and Canning Bridges). This dataset contains four lines - Floodway limit, Extent of 1 in 100 (1%) AEP flooding, Extent of floodway & Extent of study. The Floodway limit, Extent of floodway and Extent of 1 in 100 (1%) AEP Flooding and Extent of study line types are boundaries which appropriately overlay over the "FPM 1 in 100 (1%) AEP Floodway and Flood Fringe Areas" (polygon) dataset. Note: To see the full scope of the floodplain mapping, 12 dataset layers are required to be loaded in the following order: FLOODPLAIN DATASET LAYERS: FPM Flood Level Points (m AHD) FPM Flood Level Contours (m AHD) FPM 1 in 100 (1%) AEP Floodway and Flood Fringe Line FPM Extent of Flooding FPM Levee Banks FPM Location of Cross Sections FPM 1 in 100 (1%) AEP Floodplain Development Control Area FPM Map Index FPM Bridges FPM Special Development Condition Area FPM 1 in 100 (1%) AEP Floodway and Flood Fringe Area FPM Floodplain Area The dataset covers the following areas: Avon River – Toodyay, Northam, York and Beverley Townsites. Blackwood River – Augusta, Bridgetown, Nannup and Boyup Brook Townsites. Brunswick River - Greater Bunbury Coblinine River & Dorderyemunning Creek - Wagin Townsite. Collie River - Collie Townsite. Chapman River – Geraldton Townsite. Denmark River – Denmark Townsite. Gascoyne River - Carnarvon Townsite and the Lower Gascoyne. Gribble Creek - Kalgoorlie Townsite. Harding River - Roebourne Townsite. Irwin River - Dongara Townsite. Lower Collie River - Greater Bunbury. Preston River - Donnybrook Townsite. Serpentine River, Peel, Birrega & Oaklands Drains, Murray River and the Peel Inlet / Harvey Estuary - Peel Inlet / Harvey Estuary to Pinjarra and south to the Darling Scarp (Murray River) and Peel Inlet / Harvey Estuary to Wellard (Peel Main Drain), east to South Western Highway (Serpentine River) and north to Wungong Brook (Birrega Drain). Swan River, Canning River and Tributaries: Perth - Fremantle to Walyunga National Park (Swan River) and Canning Bridge to Brookton Highway (Canning River). Tributaries include Bennett Brook, Blackadder Creek, Ellen Brook, Helena River, Henley Brook, Jane Brook, St Leonards Creek, Susannah Brook (Swan River) and Southern River/ Wungong Brook (Canning River). Toby Inlet – Quindalup Townsite. Vasse-Wonnerup Estuaries, Broadwater and New River - Busselton Townsite. For further information on flooding and floodplain management in Western Australia, please refer to our Water Facts publications: Flooding in Western Australia (Water facts 13) and Floodplain Management (Water facts 14). This information is available at the following addresses: https://www.wa.gov.au/system/files/2022-11/Water-facts-13-Flooding-in-Western-Australia.pdf https://www.wa.gov.au/system/files/2022-11/Water-facts-14-Floodplain-management.pdf Glossary: Annual exceedance probability (AEP) - the likelihood of occurrence of a flood of a given size or larger in any one year; usually expressed as a percentage. 1 in 100 AEP flood - this means that there is a 1 in 100 (or 1%) chance of a flow of this size or larger occurring in any one year. This flood has a 50% chance of being experienced at least once in a person's lifetime. The 1 in 100 AEP flood has been generally adopted in Australia and overseas as the basis for floodplain management planning. Flood fringe - the area of the floodplain, outside of the floodway where development could be permitted provided it is compatible with flood hazard and building conditions provide an adequate level of flood protection. These areas are generally covered by still or very slowly moving waters during a 1 in 100 (1%) AEP flood. Floodplain - the portion of a river valley next to the river channel which is covered with water when the river overflows its banks during major river flows. The term also applies to land adjacent to estuaries which is subject to flooding. Floodway - the river channel and a portion of the floodplain where a significant flow or storage of water occurs during floods. If the floodway is even partially blocked, then the natural flooding regime of the area may be detrimentally impacted with flood levels being raised and affecting areas which may not have been previously affected. Development in floodways is to be avoided wherever possible. Australian Height Datum (AHD) - is a geodetic datum for altitude measurement in Australia. It was adopted in 1971 by the National Mapping Council as the datum to which all vertical control for mapping is to be referred. The datum is based on the mean sea level (1966-1968) being assigned the value 0.000m on the Australian Height Datum (AHD) at 30 tide gauges around the coast of the Australian continent.

Historically, low-lying land adjacent to rivers and coastlines has been favoured for settlement as they provided sources of fresh water, food, transportation and waste disposal. These areas become affected by flooding during sufficiently heavy or prolonged rainfall, high tides or storm surges and cyclones. In the north-west of the State flooding is most likely to be caused by the summer monsoon or tropical cyclones while floods in the south-west are more likely to occur in response to heavy winter rainfalls. While historical flood records and information extend as far back as 1830, detailed information on peak flood levels is typically limited to the last few decades. This dataset shows the area of inundation (polygons), i.e., the floodplain area that has occurred during the major flood events in Western Australia. Note: To see the full scope of the historical flood mapping, 3 dataset layers are required to be loaded in the following order: FLOODPLAIN DATASET LAYERS:
FPM Historical Flood Levels (m AHD) FPM Historical Extent of Flooding FPM Historical Floodplain Area The major flood events that are covered in this dataset are: Bow Bridge Townsite (June 1988) Corrigin Townsite (January 1982) Esperance Townsite (January 2007) Kupungarri to Willare (including Dales Yard & Mount Joseph gauging stations) - Fitzroy River (January 2023) Lake Grace Townsite (January 2006) Merredin Townsite (February 1979) Perth (February 2017) Tambellup Townsite (January 1982) Warmun Aboriginal Community (March 2011) York Townsite (July 2021, August 2022) Other major flood events that have occurred in the past include: Blackwood River (1945, 1955, 1963, 1964, 1982) Collie River (1945, 1963, 1964, 1974, 1982) Fitzroy River (1983, 1986, 1991, 1993, 2002, 2011) Gascoyne River (1960, 1961, 1980, 1995, 2000, 2010) Greenough River (1888, 1927, 1953, 1971, 1988, 1999, 2006) Moore River (1934, 1955, 1961, 1995, 1999) Murray River (1862, 1945, 1955, 1964) Preston River (1964, 1967, 1974, 1983, 1990, 2011) Swan River (1862, 1872, 1945, 1955, 1964, 1983) The historical flood information is used in the Department of Water and Environmental Regulation's floodplain management activities to ensure that floodplains are managed for the benefit of the whole community, minimising the risk and damages and protecting environmental values. Floodplain mapping datasets and floodplain development strategies for rivers and major watercourses in Western Australia are also available from the Department of Water and Environmental Regulation. GLOSSARY:

Annual exceedance probability (AEP) - the likelihood of occurrence of a flood of a given size or larger in any one year; usually expressed as a percentage.

1 in 100 AEP flood - this means that there is a 1 in 100 (or 1%) chance of a flow of this size or larger occurring in any one year. This flood has a 50% chance of being experienced at least once in a person's lifetime. The 1 in 100 AEP flood has been generally adopted in Australia and overseas as the basis for floodplain management planning.

Floodplain - the portion of a river valley next to the river channel which is covered with water when the river overflows its banks during major river flows. The term also applies to land adjacent to estuaries which is subject to flooding.

Australian Height Datum (AHD) - is a geodetic datum for altitude measurement in Australia. It was adopted in 1971 by the National Mapping Council as the datum to which all vertical control for mapping is to be referred. The datum is based on the mean sea level (1966-1968) being assigned the value 0.000m on the Australian Height Datum (AHD) at 30 tide gauges around the coast of the Australian continent.

Digital flood-inundation maps for coastal communities within Middlesex and Union Counties in New Jersey were created by water surfaces generated by an Advanced Circulation hydrodynamic (ADCIRC) and Simulating Waves Nearshore (SWAN) model from the Federal Emergency Management Agency (FEMA) Region II coastal analysis and mapping study (Federal Emergency Management Agency, 2014). Six synthetic modeled tropical storm events from a library of 159 events were selected based on parameters including landfall location or closest approach location, maximum wind speed, central pressure, and radii of winds. Two storm events were selected for the tide gage providing two "scenarios" and accompanying inundation-map libraries. The contents of this data release support the following publication: Suro, T.P., Niemoczynski, M.J., Boetsma, A.C., and Niemoczynski, L.M., 2023, Moderate flood level scenarios: synthetic storm-driven flood-inundation maps for coastal communities in 10 New Jersey counties: U.S. Geological Survey Scientific Investigations Report 2023-5005, 64 p., https://doi.org/10.3133/sir20235005. The landing page on which this and 24 other storm scenarios reside is: Niemoczynski, L.M., Niemoczynski, M.J., Boetsma, A.C., and Suro, T.P., 2023, Synthetic storm-driven flood-inundation grids for coastal communities in 10 New Jersey counties: U.S Geological Survey data release, https://doi.org/10.5066/P9RVF9P8. References cited: Federal Emergency Management Agency, 2014, FEMA Region II Coastal Analysis and Mapping Study, accessed November 2, 2018, at http://www.region2coastal.com/resources/about-the-coastal-flood-study/

Historically, low-lying land adjacent to rivers and coastlines has been favoured for settlement as they provided sources of fresh water, food, transportation and waste disposal. These areas become affected by flooding during sufficiently heavy or prolonged rainfall, high tides or storm surges and cyclones. In the north-west of the State flooding is most likely to be caused by the summer monsoon or tropical cyclones while floods in the south-west are more likely to occur in response to heavy winter rainfalls. While historical flood records and information extend as far back as 1830, detailed information on peak flood levels is typically limited to the last few decades. This dataset shows the extent of flooding (polylines) that has occurred during major flood events in Western Australia. Note: To see the full scope of the historical flood mapping, 3 dataset layers are required to be loaded in the following order:

The Department of Water and Environmental Regulation produces floodplain mapping of rivers and major watercourses and provides floodplain development advice to ensure that proposed floodplain development has adequate flood protection and does not impact on the existing flood regime of the area. This advice is related to major river flooding only and other issues, such as stormwater drainage and environment and ecological considerations are not addressed. This dataset comprises bridge polygons that are indicated as being either ‘Wet’ (overtopped), ‘Dry’ (not overtopped) or ‘No Data’ to describe their status during a particular flood event. The status indicates whether the bridge deck itself is overtopped and is not related to the road levels approaching the bridge. They are listed as such in the following attribute tables: STATUS_10 (1 in 10 (10%) AEP flood event) STATUS_20 (1 in 20 (5%) AEP flood event) STATUS_25 (1 in 25 (4%) AEP flood event) STATUS_50 (1 in 50 (2%) AEP flood event) STATUS_100 (1 in 100 (1%) AEP flood event) STATUS_DFE (Designated flood event) STATUS_200 (1 in 200 (0.5%) AEP flood event) STATUS_500 (1 in 500 (0.2%) AEP flood event) STATUS_MCC (Maximum channel capacity) STATUS_PMF (Probable maximum flood event) Note: To see the full scope of the floodplain mapping, 12 dataset layers are required to be loaded in the following order: FLOODPLAIN DATASET LAYERS: FPM Flood Level Points (m AHD) FPM Flood Level Contours (m AHD) FPM 1 in 100 (1%) AEP Floodway and Flood Fringe Line FPM Extent of Flooding FPM Levee Banks FPM Location of Cross Sections FPM 1 in 100 (1%) AEP Floodplain Development Control Area FPM Map Index FPM Bridges FPM Special Development Condition Area FPM 1 in 100 (1%) AEP Floodway and Flood Fringe Area FPM Floodplain Area The dataset covers the following areas: Avon River - Toodyay to Beverley and Brookton Townsites. Bandy Creek - Esperance Townsite. Blackwood River – Augusta, Bridgetown, Nannup and Boyup Brook Townsites. Bow River - Bow Bridge Townsite. Capel River - Capel Townsite. Cemetery Creek - Lake Grace Townsite. Chapman River – Geraldton Townsite. Cohn Creek - Merredin Townsite. Collie River - Collie Townsite. Corrigin Townsite. Denmark River – Denmark Townsite. Fitzroy River – Fitzroy Crossing Townsite. Five Mile Brook - Bunbury Townsite. Gascoyne River - Carnarvon Townsite and the Lower Gascoyne. Gordon River – Tambellup Townsite. Greenough River – Indian Ocean to Walkaway. Gribble Creek - Kalgoorlie Townsite. Harding River - Roebourne Townsite. Irwin River - Dongara Townsite. Katanning Townsite. Lower Collie River, Brunswick River and Wellesley River - Greater Bunbury. Margaret River – Margaret River Townsite. Preston River - Boyanup and Donnybrook Townsites. Serpentine River, Peel, Birrega & Oaklands Drains, Murray River and the Peel Inlet / Harvey Estuary - Peel Inlet / Harvey Estuary to Pinjarra and south to the Darling Scarp (Murray River) and Peel Inlet / Harvey Estuary to Wellard (Peel Main Drain), east to South Western Highway (Serpentine River) and north to Wungong Brook (Birrega Drain). Swan River, Canning River and Tributaries: Perth - Fremantle to Walyunga National Park (Swan River) and Canning Bridge to Brookton Highway (Canning River). Tributaries include Bennett Brook, Blackadder Creek, Ellen Brook, Helena River, Henley Brook, Jane Brook, St Leonards Creek, Susannah Brook (Swan River) and Southern River/ Wungong Brook (Canning River). Toby Inlet – Quindalup Townsite. Turkey Creek - Warmun Aboriginal Community. Vasse-Wonnerup Estuaries, Broadwater and New River, Abba River, Buayanup Drain, Ludlow River, Sabina River, Vasse River and Vasse Diversion Drain - Busselton Townsite. Williams River and Tributaries - Williams Townsite. Willyung Creek - Albany Townsite. Yakamia Creek – Albany Townsite. For further information on flooding and floodplain management in Western Australia please refer to our Water Facts publications: Flooding in Western Australia (Water facts 13) and Floodplain Management (Water facts 14). This information is available at the following addresses: https://www.wa.gov.au/system/files/2022-11/Water-facts-14-Floodplain-management.pdf https://www.wa.gov.au/system/files/2022-11/Water-facts-14-Floodplain-management.pdf Glossary: Annual exceedance probability (AEP) - the likelihood of occurrence of a flood of a given size or larger in any one year; usually expressed as a percentage. 1 in 100 AEP flood - this means that there is a 1 in 100 (or 1%) chance of a flow of this size or larger occurring in any one year. This flood has a 50% chance of being experienced at least once in a person's lifetime. The 1 in 100 AEP flood has been generally adopted in Australia and overseas as the basis for floodplain management planning. Floodplain - the portion of a river valley next to the river channel which is covered with water when the river overflows its banks during major river flows. The term also applies to land adjacent to estuaries which is subject to flooding. Designated flood event (DFE) - used for planning purposes and is generally the 1 in 100 (1%) AEP "designed" flood event. However, a designated flood event could be based on an "actual" flood event (e.g. Moora 1999 flood event) or an alternative scenario (i.e. Yakamia Creek - 1 in 100 (1%) AEP flood event plus sea level rise). Maximum channel capacity (MCC) - the maximum flow that a waterway can contain before breaking out across the floodplain during a flood event. Probable maximum flood (PMF) - the largest flood that could conceivably occur at a particular location, resulting from probable maximum precipitation. The PMF defines the extent of flood-prone land. Generally, it is not physically or financially possible to provide general protection against this event. Australian Height Datum (AHD) - is a geodetic datum for altitude measurement in Australia. It was adopted in 1971 by the National Mapping Council as the datum to which all vertical control for mapping is to be referred. The datum is based on the mean sea level (1966-1968) being assigned the value 0.000m on the Australian Height Datum (AHD) at 30 tide gauges around the coast of the Australian continent.