CB1CAB5A363AC0D2E040CD9B21443C90EnglishData Requests OfficerDepartment of Lands, Planning and EnvironmentGeospatial Services Unit (on behalf of department)Datarequests.DLPE@nt.gov.au2022-11-17AS/NZS ISO 19115 Geographic Information - Metadata, ANZLIC Metadata Profile1.0Borroloola Floodplain Mapping Study 20112012-05-25This report describes the flood study of the Borroloola Town area and its environs, using the URBS hydrological model and the two dimensional TUFLOW hydraulic model. The extent and severity of flooding in the modelled area has been assessed and mapped including design flood discharges, flood levels, depths, velocities, flood level contours and hazard areas, for the 20, 50, 100, 200, 500, 2000 year ARI (Average Recurrence Interval) design flood events and the Probable Maximum Flood (PMF) event. From the study it is to be noted that significant parts of the Borroloola Town and its environs are inundated by floods equal to or greater than 20 year ARI, which includes a large floodplain area to the west of Borroloola Town. There is little variation in peak flood levels across the Borroloola Town for each of the above design flood events. Significant areas of the town are inundated to maximum depths greater than 2 m for all events larger than 20 year ARI. The flood velocities across the town are not very high. However, the depth/velocity hazard is quite high across large sections of Borroloola Town and environs. The culvert and bridge structures across Rocky Creek at Robinson Road and the McArthur River at Borroloola Crossing are overtopped for all the modelled design events. Download the spatial data package (contains spatial data, maps and reports) via https://data.nt.gov.au/ You are licensed to use the DENR geospatial products on the terms and conditions set out in: Creative Commons Attribution 4.0 International Public License (CC BY 4.0) at: https://creativecommons.org/licenses/by/4.0/legalcode If you do not agree to the terms and conditions you must not use the geospatial products. You are free to copy, communicate and adapt the licensed material, provided that you abide by the licence terms (including Attribution) and attribute the licensed material using the statement: Supplied by the Department of Environment and Natural Resources. Copyright Northern Territory Government.English-16.128-16.031136.247136.3632011-11-012012-05-25datasetnot knownComplete0not knownGIS editing tools were used to rectify all overshoots and undershoots in line work. Polygon data topology rules applied are must not overlap, must not have gaps and each polygon has only one label. 0not knownGood - Derived from topographic basemap, NT cadastre. The summation of errors from all sources results in data with a standard deviation defined by scale used as +/-25m for well-defined points.0not knownThe accuracy of the attribute information is considered reasonable and conforms to guidelines as per 'Floodplain Management in Australian - Best Practice Principles and Guidelines'. Agriculture and Resource Management Council of Australia and New Zealand. SCARM Report 73 (2000).0The study was carried out by engineering consultants in consultation with the Water Resources Branch of DLRM using topographic information, hydro flood/flow datasets, hydrological modelling and field investigations. Study Source data 1:250,000 topographic maps with 50 m contours of the McArthur River catchment, 1:50,000 topographic maps with 20 m contours of the Borroloola area, digital elevation data for the Borroloola town and environs, bathymetric survey data for the Borroloola reach of the McArthur River. The 1:250,000 maps of the McArthur River catchment were used to define the boundaries of the McArthur River catchment and the tributary creeks within the catchment. The 1:50,000 maps were used to improve the definition of catchment boundaries in the Borroloola area. A DTM of the study area was developed using the following sets of digital topographic data: - 1:2,500 topographic data, including contour lines at 1.0 m intervals AHD (Australian Height datum), approximately 62 km2 in area. - 1:10,000 topographic data, including contour lines at 2.0 m intervals AHD, approximately 126 km2 in area. - Service and Land Availability Plans (SLAP) including power, water and sewerage infrastructure and topographic data (1.0 m intervals AHD) with spot heights and break lines. - Assorted datasets including cadastre, road centrelines and parcels and orthorectified aerial photography. The bathymetric data was not supplied with a datum and therefore, this data had to be integrated into the DTM using the GPS coordinates associated with each bathymetric cross- section.