{"help": "https://data.gov.au/data/api/3/action/help_show?name=package_show", "success": true, "result": {"archived": false, "author": "Fairfield City Council", "author_email": null, "contact_point": "mail@fairfieldcity.nsw.gov.au", "creator_user_id": "c2fbbe4a-4ba0-4945-808b-67454605a4cf", "duplicate_score": 2, "geospatial_topic": [], "id": "ef7acbdd-cf8a-4d92-98ec-2c42f317282e", "isopen": false, "license_id": "cc-by", "license_title": "Creative Commons Attribution 3.0 Australia", "license_url": "http://creativecommons.org/licenses/by/3.0/au/", "maintainer": null, "maintainer_email": null, "metadata_created": "2026-01-22T00:32:46.425134", "metadata_modified": "2026-01-22T00:32:52.922445", "name": "nsw-fdp-smithfield-overland-flood-study-report", "notes": "The 292 ha Smithfield overland flow catchment is located in the north-eastern portion of the\nFairfield LGA, to the south-west of Prospect Creek, and encompasses parts of the suburbs of\nSmithfield, Fairfield Heights and Fairfield West. The catchment is roughly bisected lengthways by\nthe Cumberland Highway. The catchment is highly urbanised and comprises residential, industrial\nand commercial development.\n\nThe catchment generally drains in a north-easterly direction via a network of stormwater pipes and\nflow paths, with the main trunk sections of the network running alongside the Cumberland Highway, before diverging from the Highway before the final 200m of pipe discharges into\nProspect Creek, approximately 300m downstream of the Cumberland Highway bridge.\nBecause of urban and industrial development in the catchment, parts of the stormwater network\nwere not designed to cater for the progressive increase in impervious area. Flooding problems\nalong the main overland flow paths within the catchment are exacerbated by stormwater pipes built\nunder private property and by development extending to the top of bank of open channels.\n\nThe adopted modelling approach used XP-STORM to simulate the urban sub-catchment hydrology,\nas well as the hydraulics of the stormwater pit and pipe network. Further, the approach using XPSTORM\nallowed modelling of the stormwater drainage system in conjunction with the overland\nflow in the two dimensional floodplain, with a dynamic link between the two components. The\ndynamic link between the one dimensional pipe network and two dimensional floodplain, provides\nthe best representation of flood behaviour.\n\nA one dimensional hydrologic and hydraulic model was initially established using topographic\nsurvey, spatial data and rainfall data. Relatively standard values for network and hydrologic\nparameters were assigned. A total of 259 pits and 278 pipes were represented in the model.\n\nThe floodplain in the XP-STORM model was defined as a two dimensional domain based on a 2m\ntopographic grid. Open channels were represented in the model but fencelines were excluded.\n\nBuildings were treated as solid objects within the floodplain in which floodwaters could not flow\nthrough. A downstream boundary condition was assigned based on the stage hydrographs\ndeveloped in Prospect Creek Flood Study (Bewsher Consulting, 2006).\n\nThe XP-STORM model was constructed such that overland flows may enter the next downstream\npit if there is sufficient inlet capacity. Flows in excess of the inlet capacity, or flows that surcharge\nfrom the pipe network, form overland flow which are routed through the two dimensional domain.\n\nAlthough the model could not be calibrated because of a lack of historical data, model results were\ncompared and found to agree relatively well with the findings from previous drainage\ninvestigations and Council\u2019s database of known flooding trouble spots.\n\nSensitivity analyses revealed that the XP-STORM model was not sensitive to changes in\nManning\u2019s n roughness values and only partially sensitive to increases in rainfall intensities.\n\nIncreasing blockage factors of pits increased flood depths in some residential areas at the upstream\nends of the drainage network.\n\nThe model was run for the 20, 100, 200, 500, 2000, 10,000 year average recurrence interval (ARI)\nevents and the PMF, for a range of storm durations from 30 minutes to three hours. The peak water\nlevel and velocity for each storm duration, at each 2D grid point, were extracted and used to form a\n\u2018peak of peaks\u2019 grid that was subsequently used a basis for the flood mapping.\n\nFlood model results and the flood mapping for the 100 year ARI event indicate that:\n? There are a number of overland flowpaths which originate in the upper catchment and carry\nstormwater in a north to north-west direction towards the Cumberland Highway. Stormwater\nis carried along Maud Street in the south of the catchment, across Reserve Street onto\nRosemount Avenue. In the east of the catchment, stormwater is carried along Oxford Street,\nacross Brennan Street and breaks through properties on Oxford Street to join the flow path\nalong the Cumberland Highway. In the west of the catchment, there is a flowpath along\nO\u2019Connell Street which carries stormwater south towards Brenan Street to the Cumberland\nHighway.\n\n? Overland flooding is generally deepest in open space areas adjacent to the Highway, where\nflood water is ponding, particularly between Brenan Street and the Boulevard. Depths in these\nare in the range of 0.6-1.0m. Flood depths in excess of 1m are located in the flowpath between\nRosemount Avenue and the Cumberland Highway. Typical depths of flooding at properties in\nthe upper parts of the catchment are less than 0.3m. In the middle part of the catchment a\nnumber of properties in the Rosemount Avenue, Alexander Street and Brenan Street area are\naffected by overland flood depths between 0.5m and 0.8m. In the lower catchment, north of\nHorsley Drive, a small number or properties are affected by overland flood depths of up 1.2m.\n\n? The depth of flooding in road corridors is typically less than 0.3m. Some roads experience\nflooding greater than 0.5m deep, and include Percy Street, Beemera Street, Ainslie Street,\nMusgrave Crescent, Reserve Street and Oxford Street. There are small sections of road on\nRosemont Avenue and Alexander Street where overland flood depths are greater than 1m.\n\n? Overland flow velocities within properties in the 100 year ARI event across the study area are\ntypically less than 0.5m/s. There are some isolated areas (for example properties fronting the\nCumberland Highway) where flow velocities are between 1-1.5m/s. Higher velocities, greater\nthan 1.5m/s are observed on some streets, including the Cumberland Highway and Maud\nStreet.\n\nFlood risk precinct maps were prepared based on modelling of the 100 year ARI (medium risk) and\nPMF (low risk) events and using the flood risk precinct categories outlined in the Fairfield City-\nWide Development Control Plan. The flood risk precinct mapping has identified:\n? Approximately 1365 properties are within the floodplain outline defined by the PMF event.\n\n? Areas of high flood risk occur in: the lower catchment south of Kiola Street; in the middle\ncatchment at the Rosemont Avenue/Alexander Street intersection; and at the corner of Brenan\nStreet and Cumberland Highway.\n\n? The medium flood risk precinct follows the pattern of the trunk drainage system from the\nupper to lower catchment.", "num_resources": 1, "num_tags": 3, "organization": {"id": "d6ac6906-7852-4875-ba2b-7c0ec1f24ba3", "name": "fairfield-city-council-datansw", "title": "Fairfield City Council", "type": "organization", "description": "Fairfield City is 32km south-west of the Sydney Central Business District and covers an area of 104 square km, incorporating 27 suburbs. Located in Western Sydney, its neighbouring areas are Parramatta and Liverpool, as well as the councils of Cumberland, the new Canterbury Bankstown, Blacktown and Penrith.\r\n\r\nhttp://www.fairfieldcity.nsw.gov.au/\r\n\r\nThe impact of development in the past 50 years has resulted in severe degradation of the natural habitat and water quality in these creeks and wetlands that feed into the City's three catchments: \r\n\r\nThe Hawkesbury-Nepean Catchment to the west fed by the South Creek Sub-Catchment consisting of South Creek, Eastern Creek and Ropes Creek and the Georges River Catchment to the south and east fed by the sub-catchments of Prospect Creek and Cabramatta Creek. \r\n", "image_url": "", "created": "2025-06-24T04:51:54.501519", "is_organization": true, "approval_status": "approved", "state": "active"}, "original_harvest_source": {"site_url": "https://data.nsw.gov.au/data/", "href": "https://data.nsw.gov.au/data/dataset/nsw-fdp-smithfield-overland-flood-study-report", "title": "DataNSW"}, "original_name": "nsw-fdp-smithfield-overland-flood-study-report", "owner_org": "d6ac6906-7852-4875-ba2b-7c0ec1f24ba3", "private": false, "promotion_level": "0", "remote_last_updated": "2026-01-14 22:08:38.180301", "spatial": "{\"type\": \"Point\",\"coordinates\": [147.0179,-32.1618]}", "spatial_coverage": "New South Wales (NSW81093)", "state": "active", "temporal_coverage_from": "2025-12-17 02:16:28.144396", "temporal_coverage_to": "2011-05-01 00:00:00", "title": "Smithfield Overland Flood Study", "type": "dataset", "unpublished": false, "url": null, "version": null, "extras": [{"key": "harvest_object_id", "value": "03dee192-8a09-49cf-8d3d-b6e6f15d2909"}, {"key": "harvest_source_id", "value": "9ebac586-8e51-4904-9f6c-d9b79726659a"}, {"key": "harvest_source_title", "value": "DataNSW"}], "resources": [{"cache_last_updated": null, "cache_url": null, "created": "2026-01-14T22:08:38.202606", "datastore_active": false, "datastore_contains_all_records_of_source_file": false, "format": "HTML", "hash": "", "id": "cc253abc-5dec-41c9-8788-65417f64f3d2", "last_modified": null, "metadata_modified": "2026-01-22T00:32:46.421460", "mimetype": null, "mimetype_inner": null, "name": "Smithfield - Overland Flood Study", "package_id": "ef7acbdd-cf8a-4d92-98ec-2c42f317282e", "position": 0, "resource_type": null, "size": null, "state": "active", "url": "https://flooddata.ses.nsw.gov.au/dataset/2adcdbad-e101-44d2-8dfb-4e5cb18e4803/resource/fece2536-d075-48e2-b6ff-886473fdcaaa", "url_type": null, "zip_extract": false}], "tags": [{"display_name": "Smithfield", "id": "9190334d-8434-4395-ba13-7b9d2a6a1489", "name": "Smithfield", "state": "active", "vocabulary_id": null}, {"display_name": "hydraulic model", "id": "5ea1bf91-c991-4e1b-808e-2528b9741aa5", "name": "hydraulic model", "state": "active", "vocabulary_id": null}, {"display_name": "hydrologic model", "id": "306ddc3f-3866-4055-8fd7-0e4cd32a2a1a", "name": "hydrologic model", "state": "active", "vocabulary_id": null}], "groups": [], "relationships_as_subject": [], "relationships_as_object": []}}