Description: The Gwydir FMP boundary was initially based on the Lower Gwydir designated floodplain (designated under the Water Act 1912 on the 18th October 1984). The boundary was refined to consider water sharing plans, floodplain harvesting works and aligned to topographical features where applicable for ease of administration and clarity for water users.The Gwydir Valley FMP commenced on the 12 August 2016.Detailed description of how the boundary was developed:Principles for Developing VWFMPThe current designated floodplain (WA 1912) was the starting point for the development of a newVWFMP boundary, to ensure consistency with current management that includes areas of existingand potential new floodplain development in the Gwydir. In order to achieve the purpose andobjectives for this Plan as listed above, the designated floodplain was varied according to theprinciples detailed below.Existing designated Gwydir floodplain: Existing designated floodplain areaused to determine the area of the valleyin which Part 8 of the Water Act 1912currently applies.Basis for capturing existing and potential floodplaindevelopments within the Gwydir Valley.Hydrological Effect: The boundary will include additionalflood control works that are outside theexisting designated floodplain area.To meet the objectives of the plan and to assistcoordination of all flood control workdevelopment on the floodplain.Ease of administration.Cadastral Relevance: Where appropriate the boundary willalign with significant cadastral features.Ease of administration.Provides clarity for water users.Planning Legacy: Unregulated WSPs: Where appropriate the boundary willalign with relevant unregulated watersource boundaries.Consistency with other boundaries for watermanagement plans under the WMA 2000.Ease of administration.Clarity for water users.Planning Legacy: Regulated WSPs: Where appropriate the boundary willalign with relevant floodplain harvestingboundaries contained in regulatedWSPs of the Barwon-Darling.The location of flood works used to capturewater for floodplain harvesting is includedwithin the boundary of the valley in which thepoint of take has been accounted, or;the point of take is located within the valley inwhich the associated floodplain harvesting hasbeen accounted.Floodplain Harvesting:Boundary will be aligned to includeareas identified through the FloodplainHarvesting Project’ register of interestprocess and potential floodplainharvesting structures. To ensure consistency with the FloodplainHarvesting (FPH) Policy. The FPH Policy onlyapplies to floodplain harvesting activities onproperties where all or part of that property lieswithin the designated floodplain.
Copyright Text: OEH Healthy Floodplains Unit in conjuction with DPI, Water.
Description: Management Zone A (Major discharge areas for design floods):Zone A includes floodways that convey significant floodwater discharge during small (2004) and large (2012) design floods. This zone is also important for the conveyance of floodwater to floodplain assets during large and small flood events (environmental flow releases).Uncontrolled flood work development in this zone may have a high adverse impact on flood behaviour.Delineation of this zone also has socioeconomic benefits. Limiting flood work development in this zone will prevent flood flow redistribution, increased flood velocities and flood levels which may adversely impact on life and property.Zone A ensures that there is continuity of flow and flowpaths and assists in maintaining the overall flow distribution on the floodplain.Management Zone B (Flood storage and discharge areas for design floods)Zone B includes areas of the floodplain that are important for the temporary storage of floodwaters during the passage of a flood. The outer boundary of this zone is defined by the inundation extent of the large design flood.Zone B is important for conveyance of flood water to floodplain assets during larger flood events, such as in the large design flood.Controlling flood work development in this zone is important to manage the cumulative and local impact of works on flood behaviour.Management Zone C (Flood fringe areas for floods greater than design floods and existing developed areas) Zone C includes areas outside of the inundation extent of the large design flood and existing developed areas.Flood work development in the remaining flood fringe areas is unlikely to have a significant effect on the flood behaviour. Flood works would still require an assessment and approval to protect the health of the floodplain environment.Management Zone D (Special environmental protection zone) Zone D is an environmental protection zone taken from the Lower Gingham FMP. This zone includes a core wetland area that is highly significant. The inclusion of this zone in the Gwydir FMP is to ensure consistency with the existing floodplain management planning arrangements and flood connectivity to this area is maintained and protected.
Copyright Text: OEH Healthy Floodplains Unit and OEH Waters, Wetlands and Coasts Science Branch and OEH Native Vegetation Information Science Branch
Description: Hydraulic flood modelling of the large (2012) design floods in the Gwydir floodplain under existing development conditions was used to determine acceptable re-distribution of peak flood flows at a regional/floodplain scale.
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Description: This spatial data represents the footrpint (area enclosed by existing flood works). Existing development footprint may contain spatial delineation of levees, banks, supply channels, infrastructure protection works, roads and storages. However, where a flood work is a linear area that does not form a polygon or enclose an area, these works are not delineated in this spatial data. This may occur where a supply channel runs from the river onto a property. This area of conveyance would not be mapped unless it enclosed an area with other associated flood-work developments.
Copyright Text: Data owned by DPI, Water. Initial licence information extracted from DPI, Water Licence Administration System. Contributions to data refinement have been made by the Healthy Floodplains Unit in Office of Environment and Heritage.
Description: This spatial data only includes ecological and cultural refinements to Management Zone A, in addition to the floodway network. These refinements were based on the flood dependency and ecological and cultural significance of assets in the floodplain. These refinements are incorporated into the Management Zone data but are provided separately like the floodway network in order to identify the individual components that comprise the Gwydir Management Zones.
Copyright Text: OEH Healthy Floodplains Unit and OEH Water, Wetlands and Coast Science Branch
Description: Priority vegetation assets to inform development of the Gwydir Valley FMP floodplain management plan 2015. Composite vegetation map derived from Gwydir Wetlands and Floodplain Vegetation Mapping, 2008 - VIS_ID 3922 and Composite vegetation map for the Border Rivers-Gwydir Catchment (2009) VIS_ID 3801. Refer to Gwydir Flood Behaviour Investigation Report for further information.Composite vegetation map derived from Gwydir Wetlands and Floodplain Vegetation Mapping, 2008 - VIS_ID 3922 and Composite vegetation map for the Border Rivers-Gwydir Catchment (2009) VIS_ID 3801
Copyright Text: 1. NSW Office of Environment and Heritage (2013) Gwydir Floodplain Management Plan: Flood Behaviour Investigation. Report prepared for the Healthy Floodplains Project. Unpublished report.
2. Bowen, S and Simpson, S. L. (2010). Changes in the Extent and Condition of the Vegetation Communities of the Gwydir Wetlands and Floodplain 1996-2008. Final Report for the NSW Wetland Recovery Program. NSW Department of Environment Climate Change and Water, Sydney. (Gwydir Wetlands 2008. VIS Dataset ID: 3922).
3. Eco Logical Australia (2008). Vegetation Mapping for the Namoi and Border Rivers-Gwydir CMAs: Compilation of API Datasets and Preparation of a Hierarchical Vegetation Classification. Final Report for Border Rivers-Gwydir and Namoi CMAs. Project Nos. 125-002 & 129-002. March 2008. (brg_comp09. VIS Dataset ID: 3801).
4. NSW Office of Environment and Heritage (2015). BRG-Namoi Regional Native Vegetation Mapping. Technical Notes, NSW Office of Environment and Heritage, Sydney, Australia. (BRG Namoi v2. VIS Dataset ID: 4204).
Description: Hydraulic flood modelling of the large (2012) and small (2004) design floods in the Gwydir floodplain.Floodway network is based on hydraulic model output areas that have a Depth-Velocity Product (DVP) that is ≥0.1m2/sec of velocity for the large design flood. The floodway network is comprised of 'Floodway' which are areas ≥0.1m2/sec and are the primary basis for Management Zone A. The remaining areas of the floodway network data includes the 'inundation extent' of the large design flood. These areas form the hydraulic basis for Management Zone B.
Value: Inundation extent of the small (2004) and large (2012) modelled design floods Label: Inundation extent of the small (2004) and large (2012) modelled design floods Description: Symbol:
Description: The Barwon-Darling Valley Floodplain Boundary. The area within the boundary is declared to be a floodplain under the Water Management (General) Regulation 2011.The upstream limit of the floodplain is at Mungindi on the Barwon River, at the New South Wales (NSW), Queensland border and the downstream limit is approximately 20 km downstream of Louth on the Darling River. The northern boundary and part of the southern boundary of the floodplain are confined to higher ground and include a limited extent of contributing influence streams. The remaining parts of the southern boundary are aligned to boundaries of other rural floodplain management plans.The boundary of the Barwon-Darling Valley Floodplain was delineated based on the consideration of the following:Designated floodplains and floodplain development guidelinesExisting and potential floodplain developments in the Barwon-Darling Valley Floodplain were identified from the following existing floodplain areas designated under Part 8 of the WA 1912: Bogan River Confluence to Louth designated floodplain, rural flood study (URS 2009)Lower Macquarie designated floodplainLower Macintyre designated floodplainSmall sections of the Lower Gwydir and Lower Namoi designated floodplainsLittle Bogan River to Yanda Creek floodplain guidelines (WRC 1986a), andDarling River – Yanda Creek to Louth floodplain guidelines (WRC 1986b.The WA 1912 was repealed in 2015 and all existing designated floodplains under this Act transitioned across to the WMA.Hydraulic effects of developmentThe floodplain was extended to include additional flood works that were outside the existing designated floodplain areas to meet the objectives of the Barwon-Darling Valley FMP and to assist with the coordination of all flood works across the extent of major flooding.Cadastral and administrative relevanceWhere appropriate, the floodplain was aligned with significant cadastral features (e.g. property, parish, county, LGA and State boundaries; roads and railways) to simplify administration and to provide clarity to water users.Planning legacy (unregulated water sharing plans (WSPs))Where appropriate, the boundary was aligned with unregulated WSP boundaries to ensure consistency with boundaries of water management plans under the WMA, ease of administration and increased clarity for water users.Floodplain harvestingThe floodplain boundary included areas identified through the Floodplain Harvesting Project’s expression of interest process for floodplain harvesting licences and potential floodplain harvesting structures. This ensures consistency with the NSW Floodplain Harvesting Policy (NSW DPI 2013), which only applies to floodplain harvesting activities on properties where all or part of that property lies within the designated floodplain.Other FMP floodplain boundariesThe Barwon-Darling Valley Floodplain was aligned with FMP boundaries of the Border Rivers, Gwydir, Lower Namoi and Macquarie valleys to provide consistency with other water management plan boundaries under the WMA 2000.Landscape featuresWhere appropriate, the boundary was aligned with significant landscape features, such as weirs, to assist ease of administration and to provide clarity for water users.
Copyright Text: OEH Healthy Floodplains Unit in conjuction with DPI, Water.
Description: The nature and location of the management zones in the Barwon-Darling Valley Floodplain was determined using hydraulic, ecological and cultural criteria as well as criteria to ensure the plan reflects existing floodplain management arrangements. This approach considered the impact of existing and future development on flooding in rivers and floodplains; the flood risk to life and property; the flood connectivity of floodplain assets and the social and economic impacts of restricting flood-work development. Management zones for the Floodplain Management Plan for the Barwon-Darling Valley Floodplain 2017. There are five management zones:Barwon-Darling Management Zone A: includes major drainage lines and other areas where a significant discharge of floodwater occurs during all flood events. The areas are generally characterised by high flood flow velocity and depthBarwon-Darling Management Zone B: includes areas of the floodplain that are important for the conveyance of floodwater during large flood events and for the temporary pondage of floodwaters during the passage of a flood. Its outer boundary is defined by the modelled inundation extent of the large design floodBarwon-Darling Management Zone C: includes elevated areas or areas protected by existing flood work developmentBarwon-Darling Management Zone CU: includes urban areas where there is either a flood study, a flood risk management study, a flood risk management plan, or that are protected by flood mitigation works such as town levees.Barwon-Darling Management Zone D: is a special protection zone for areas of high ecological and/or cultural significance. Criteria used to develop the management zones:MANAGEMENT ZONE AHydraulic criteriaMZ A includes major discharge areas that have a DVP of greater than or equal to 0.3 m2/s for the large design flood (1976).Floodplain connectivity was provided for by incorporating:parts of the small design flood extent (2011) and/orfloodplain areas that support tributary flows and outer floodplain floodways that have a DVP of greater than or equal to 0.10 m2/s for the large design flood (1976).Ecological criteriaMZ A includes, where there is hydraulic justification:semi-permanent wetlandconnections to/through floodplain wetland (flood-dependent shrubland wetlands) and flood-dependent forest/woodland (wetlands)tracts of floodplain land within low-lying areas bordering a watercourse that contain floodplain wetland (flood-dependent shrubland wetland) or flood-dependent forest/woodland (wetlands)key fish passage areas identified using NSW Fish Community Status and Threatened Fish Species Data - Aquatic Biodiversity Value Mapping Project (NSW DPI 2016)Cultural criteriaMZ A includes, where there is hydraulic justification:floodplain areas with Aboriginal values that are highly flood-dependent that were identified during direct community consultation with the local Aboriginal community and/or are listed on the AWIS and AHIMS databaseslocations for scarred/carved trees that are living flood-dependent vegetation that generally require frequent flooding to maintain their ecological character and cultural valuelocations for heritage sites that are flood dependent and are cultural heritage objects and places as listed on Commonwealth, state and local government heritage registers.Existing floodplain management arrangements criteriaExisting floodplain development guidelines prepared to support assessment for applications under Part 8 WA 1912 were reviewed and minor changes were made to MZ A to incorporate this historical flood behaviour information. MZ A was made congruent with the MZ A of the bordering Gwydir, draft Border Rivers, draft Macquarie and draft Lower Namoi Valley FMPs.MANAGEMENT ZONE BHydraulic criteriaMZ B includes the inundation extent of the small and large design floods and any areas protected by existing flood works that are overtopped by the large design flood.Ecological criteriaMZ B includes, where there is a hydraulic justification, flood-dependent woodland and to a lesser degree flood-dependent forest/woodland (wetlands) where there was no hydraulic justification for inclusion in MZ A. Cultural criteriaMZ B includes, where there is hydraulic justification, locations for scarred/carved trees that are living and located within flood-dependent woodland.Existing floodplain management arrangements criteriaMZ B was made congruent with MZ B of the bordering Gwydir, draft Macquarie and draft Lower Namoi Valley FMPs. MZ B includes some area of the floodplain that are enclosed by existing flood works that are designed to be overtopped during moderate to large floods. MANAGEMENT ZONE CHydraulic criteriaMZ C includes flood fringe areas of the floodplain that are outside the large design flood and areas enclosed by existing flood works that are not designed to be overtopped during flooding.Ecological criteriaThe basis of MZ C was not ecological. However, some ecological assets that have been enclosed by existing approved flood works are located in MZ C.Cultural criteriaThe basis of MZ C was not cultural. However, some cultural assets that have been enclosed by existing approved flood works are located in MZ C.Existing floodplain management arrangements criteriaExisting flood-work development identified in floodplain management guidelines were incorporated into MZ C. MANAGEMENT ZONE CUHydraulic criteriaThe basis for MZ CU was not hydraulic.Ecological criteriaThe basis of MZ CU was not ecological.Cultural criteriaThe basis of MZ CU was not cultural.Existing floodplain management arrangements criteriaMZ CU includes floodplain areas that are included within existing urban flood studies, flood risk management studies, or flood risk management plans or that are protected by flood mitigation works such as town levees.MANAGEMENT ZONE DHydraulic criteriaThe basis for MZ D was not hydraulic. Ecological criteriaMZ D includes assets that are a location of landscape feature, such as a swamp, marsh, lagoon, anabranch or billabong with a high degree of floodwater dependency, and:a high degree of habitat complexitya history of supporting a diversity or abundance or waterbird, native fish or frog populationsthe functional capacity to act as an aquatic drought refugeis susceptible to conversion or loss of flood connectivity due to flood-workrecognition in, or protected by a local, state or commonwealth environmental policy.Cultural criteriaMZ D includes areas that have a high degree of floodwater dependency, such as swamps, marshes, lagoons, billabongs, rocky bars or warrambools and have significance to the Aboriginal community, including spiritual, archaeological or resource use-values. These areas were listed on a heritage register or were a place that was recognized for its cultural significance by several senior knowledge holders in the Aboriginal community.Existing floodplain management arrangements criteriaMZ D was reviewed for consistency with existing plans, however, the basis for MZ D did not include existing floodplain management planning arrangements
Copyright Text: Office of Environment and Heritage: Healthy Floodplains Unit; and Waters, Wetlands and Coasts Science Branch.
Description: Hydraulic flood modelling of the large (1976) design floods in the Barwon-Darling floodplain under existing development conditions was used to determine acceptable re-distribution of peak flood flows at a regional/floodplain scale. Used to help assess cumulative impacts associated with flood-work development
Copyright Text: Office of Environment and Heritage: Healthy Floodplains Unit
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Description: Priority Flood dependent vegetation assets used to inform development of the Barwon Darling FMP floodplain management plan 2017. Composite vegetation map derived from Refer to Source_VIS field in attribute table for source data.1. Shultz, N., Gowans, S., and Westbrooke, M. (2014) Survey and mapping of Darling floodplain vegetation between Tilpa and Brewarrina. September 2014. Report prepared for the NSW Government – Office of Environment and Heritage by Centre for Environmental Management, Federation University Australia, Ballarat. 2. Eco Logical Australia 2015. Vegetation of the Barwon-Darling and Condamine-Balonne floodplain systems of New South Wales: Mapping and survey of plant community types. Prepared for Murray-Darling Basin Authority.’ 3. Gowans S, Milne, R, Westbrooke, M & Palmer G (2012) Survey of vegetation and vegetation condition of Toorale, Version 1-1. Unpublished report to NSW Office of Environment & Heritage. Centre for Environmental Management, University of Ballarat, Mt Helen, Victoria. 4. Hunter, J. (2010). Vegetation and Floristics of The Barwon Nature Reserve. A report prepared for the Department of Environment, Climate Change and Water (DECCW). 5. Peasley, B., and Walsh, A. (1999). Mapping Vegetation Landscapes of the NSW North Western Slopes and Plains - A Project Overview. NHT Project NW0339.97. Report to the Natural Heritage Trust and North West Catchment Management Committee, Department of Land and Water Conservation. 6. Pickard, J., and Norris, E.H. (1994). The natural vegetation of north-western New South Wales: notes to accompany the 1:100 000 vegetation map sheet, Cunnighamia, Vol. 3, 3. Department of Infrastructure, 7. Planning and Natural Resources (DIPNR) (1998a). Preclearing and Existing Vegetation Mapping of the Western Division section of Bourke Shire, Northern Floodplains Far Western NSW, Edition 3. 8. Department of Infrastructure, Planning and Natural Resources (DIPNR) (1998b). Preclearing and Existing Vegetation Mapping of the Western Division section of Brewarrina Shire, Northern Floodplains Far Western NSW, Edition 2. 9. Department of Infrastructure, Planning and Natural Resources (DIPNR) (1998c). Preclearing and Existing Vegetation Mapping of the Western Division section of Walgett Shire, Northern Floodplains Far Western NSW, Edition 3. 10. Eco Logical Australia (2008). Vegetation Mapping for the Namoi and Border Rivers-Gwydir CMAs: Compilation of API Datasets and Preparation of a Hierarchical Vegetation Classification, final report for Border Rivers-Gwydir and Namoi CMAs. 11. Bowen, S., and Simpson, S. (2009). 2008 Vegetation map for the Gwydir wetlands and floodplain. NSW Department of Environment Climate Change and Water. Sydney South NSW. 12. Office of Environment and Heritage (2016). State Vegetation Type Map: Border Rivers Gwydir Namoi. Version 2.1. Office of Environment and Heritage, Sydney, Australia. 13. Some features from NSW Hydro Area Dataset were unioned into the vegetation composite layer
Description: This spatial data represents the footprint (area enclosed by existing flood works). Existing development footprint may contain spatial delineation of levees, banks, supply channels, infrastructure protection works, roads and storages. However, where a flood work is a linear area that does not form a polygon or enclose an area, these works are not delineated in this spatial data. This may occur where a supply channel runs from the river onto a property. This area of conveyance would not be mapped unless it enclosed an area with other associated flood-work developments.Department of Primary Industries, Water. Initial licence information extracted from DPI, Water Licence Administration System. Contributions to data refinement have been made by Office of Environment and Heritage, Healthy Floodplains Unit.
Copyright Text: Office of Environment and Heritage, Healthy Floodplains Unit and Department of Primary Industries, Water.
Description: This dataset includes ecological and cultural refinements to Management Zone A, in addition to the floodway network. These refinements were based on the flood dependency and ecological and cultural significance of assets in the floodplain. These refinements were incorporated into the Management Zone data but are provided separately like the floodway network to identify the individual components that comprise the Barwon-Darling Management Zones.This dataset should be viewed with the Barwon_Darling_FMP_2017_Ecological_Assets_Flood_Dependent_Vegetation_250717 dataset.
Copyright Text: Office of Environment and Heritage: Healthy Floodplains Unit and Waters, Wetlands and Coasts Science Branch.
Description: The floodway network map represents those areas on the floodplain that have adequate hydraulic capacity and continuity to effectively convey flood waters. It is comprised of:a coordinated and integrated network of floodways where a significant discharge of floodwater occurs during floodsthe inundation extent of small and large design floodsareas that preserve floodplain connectivityareas that provide sufficient pondage for floodwater.Two hydraulic categories are mapped in the floodway network:floodways, which are areas where a significant discharge of floodwater occurs during design floodsinundation extent, which includes areas of the floodplain that are important for the temporary storage of floodwaters during the passage of a flood.Two design floods were used to model the floodway network:design flood of 1976 (1.4% AEP at Walgett and 1.2% AEP at Bourke gauging stations i.e. the large design flood)design flood of December 2011 (17% AEP at Walgett and Bourke gauging stations i.e. the small design flood).The floodway network was determined using:hydraulic model outputs:- depth-velocity product maps for the large design flood - areas that reached the depth-velocity product threshold of ≥0.3m2/s were categorised as floodways- areas that support tributary flows and outer floodplain floodways that have a DVP of ≥ 0.1m2/s were also categorised as floodways- discharge and velocity values along flow paths- inundation extent for the small and large design floodsother data:- flood aerial photography and satellite imagery- spatial watercourse layers and topographical mapping- previous rural floodplain management plans and guidelines- local knowledge obtained from floodplain communities and floodplain managers.
Copyright Text: Office of Environment and Heritage: Healthy Floodplains Unit
Value: Inundation extent of the small (2011) and large (1976) modelled design floods Label: Inundation extent of the small (2011) and large (1976) modelled design floods Description: Symbol:
Description: The Upper Namoi Valley Floodplain Boundary. The area within the boundary is proposed to be declared a floodplain under the Water Management (General) Regulation 2011.
Copyright Text: OEH Healthy Floodplains Unit in conjunction with DPI, Water.
Description: Managemnt zones were defined based on hydraulic, ecological, cultural and socio-economic criteria. The seven zones include:MZ AD - Major Discharge Areas, Defined FloodwaysMZ AID - Major Discharge AreasIll Defined Floodways MZ BL - Flood Storage and Secondary Flood Discharge Areas, MZ BU - Flood Storage and Secondary Flood Discharge AreasMZ C - Flood Fringe and Flood Protected Developed AreasMZ CU - Urban areas managed by Local CouncilMZ D - Special Environmental and Cultural Protection ZoneFollowing the Floodplain Management Plan, the management zones indicate what rules apply for the granting or ammendment of flood work approvals.The risk to life and property from the effects of flooding is addressed in the design of the management zones and the rules for granting or amending flood work approvals by:identifying hydraulic thresholds within management zones where the local and cumulative impact of flood work development should be limited to prevent flood flow redistribution, increased flood velocities and flood levels, anddeveloping rules to limit the granting of flood work approvals for flood works that are minor in nature, including flood protection works to protect infrastructure and livestock, in zones where major flood discharge occurs (Upper Namoi Management Zones AD, AID and D), anddeveloping rules to allow landholders to apply for certain flood protection works in Upper Namoi Management Zones BU and BL (where temporary storage of large floods occurs) without requiring advertising, to protect infrastructure, crops and livestock from flood events, andspecifying the nature of flood works that can be constructed.
Description: Display using 'Small_flood'Small design floods ensure that critical flow paths to floodplain assets were condiered furing development of the flood way network. Most of Upper Namoi used a Probabilisitic 20% AEP small desing flood, with Warrah Creek area using 1992 small desing flood.
Description: Display using 'Large_design'The Upper Namoi has been divided into several sub-areas. These sub-areas conform to the existing rural floodplain management studies and plans where hydraulic modelling was previously performed. For areas that are not covered by an existing plan, sub-areas have been delineated to represent geographical recognisable areas (e.g. Boggabri to Narrabri-1984 event, and Breeza to Ruvigne-1 in 10 Year design Event). This shapefile spatially identifies the different large design floods for each area.While a consistent design flood across the valley would be neater, there are several reasons for utilising the existing design floods:•Allow for continuity between the existing and valley wide plan•The variability of the ARI across the valley, means no one historical event can be used•Hydrology modelling and calculations would need to be re-done, some files and calculations may be missing.MIKE 11 was used for all modelsModel datasets from existing rural floodplain management studies, within the Upper Namoi boundary, were used. These datasets (cross-sections, flowlines, floodmarks, etc) can be found within the NAMOI data package for the following areas:Upper CoxsLower CoxsCarroll to BoggabriUpper YarramanWarrah CreekBorambil GunnadillyBlackvilleCaroon to Breeza
Description: This spatial data represents the footprint (area enclosed by existing flood works). Existing development footprint may contain spatial delineation of levees, banks, supply channels, infrastructure protection works, roads and storages. However, where a flood work is a linear area that does not form a polygon or encclose an area, these works are not delineated in this spatial data. This may occur where a supply channel runs from the river onto a property. This area of conveyance would not be mapped unless it enclosed an area with other associated flood-work developments. Data includes license numbers but verification with licensing officers is recommended. Data also indicated where the flood work was considered to be above ground and mapped as MZ C in the management zones
Copyright Text: OEH Healthy Floodplains Unit with aide from DPI water
Description: (1) The Aboriginal values that have been identified for the purposes of this Plan are the flood-dependent assets described in subclause (2). The functions, services and features identified as benefiting Aboriginal people and their cultures described in subclause (3) are listed in one of the following:(a) Aboriginal Heritage Information Management System,(b) Aboriginal Water Initiative System,(c) Murray Darling Basin Authority Aboriginal Submissions Database,(d) NSW State Heritage Register, (e) Commonwealth Heritage List,(f) any other source that has been deemed relevant by the Minister.(2) Aboriginal values that have been identified as flood-dependent assets for the purposes of this clause are:(a) places or sites that are, or could be, used for cultural activities and that benefit from flooding, such as fish traps made of stone or sticks, and(b) flood-dependent ecological assets that:(i) are recognised for their spiritual and/or cultural significance, or(ii) have been culturally modified, including:(A) scarred trees, and(B) tree carvings, or(iii) are or contain resources that are or were utilised in cultural activities, or (iv) are associated with places that are used for contemporary cultural activities.(3) Aboriginal values involving the following functions, services and features identified as benefiting Aboriginal people and their cultures for the purposes of this clause are:(a) Aboriginal cultural processes that are dependent on flooding, including:(i) harvesting traditional flood-dependent resources, and(ii) cultural activities connected with and dependent upon flood events, (b) continuation of Aboriginal cultural practices connected with flooding, (c) preservation and longevity of Aboriginal values, (d) maintaining potential for cultural renewal, (e) maintaining spiritual connection with the floodplain landscape.
Description: Floodway network (hydraulic basis for the management zones) was designated based on 2D hydraulic modelling, existing floodway networks in current FMPs(Namoi water plan), stream orders, flood imagery, ADS40 DEM, topographical mapping and slope.The Floodway Network Map represents those areas on the floodplain that have adequate hydraulic capacity and continuity to effectively convey flood waters. It is comprised of: a coordinated and integrated network of floodways where a significant discharge of floodwater occurs during floods, andthe inundation extent of small and large design floods, andareas of significant discharge of the large design flood, andareas that preserve floodplain connectivity, and areas that provide sufficient pondage for floodwater.The Upper Namoi floodway network is comprised of three hydraulic categories: Defined floodways (37,000 ha or 6% of the floodplain), which are major discharge areas with definedchannels or riverbanks. A significant discharge of floodwater occurs during design floods and these areasare important for the continuity of flood flows over the floodplain. Ill-defined floodways (39,700 ha or 7% of the floodplain), which are major discharge areas that areoverland flow paths with no defined channels or riverbanks. A significant discharge of floodwater occursduring design floods and these areas are important for the continuity of flood flows over the floodplain. Inundation extent (255,400 ha or 43% of the floodplain), which includes areas of the floodplain that areimportant for the temporary storage of floodwaters during the passage of a flood and for secondary flooddischarge. Flood works that are limited height are included in the inundation extent, whereas those that arenot overtopped by flooding are excluded.
Description: The Lower Namoi Valley Floodplain Boundary, which covers 570,700 hectares, was defined to capture the floodplain areas inundated during flooding of the major rivers running between Narrabri and Walgett and to include any works that may affect flooding. The existing Lower Namoi Floodplain designated under section 166 Part 8 of the WA 1912 on 18 September 1984 was the basis for capturing existing and potential floodplain developments within the floodplain. The overall extent of boundary change when compared to the existing designated floodplain was the addition of 57,400 hectares in some areas and the subtraction of 175,600 hectares in other areas. Changes were made to the existing floodplain to delineate the new Lower Namoi Valley Floodplain boundary.Where appropriate, the boundary was adjusted to align with significant cadastral features, such as the Walgett to Pilliga Road, to ease administration and provide clarity to water users.The largest proposed change is at the northern boundary where 174,000 hectares of the existing floodplain were removed when delineating the new proposed floodplain boundary. This change was proposed to align with the wsp for the Gwydir Unregulated and Alluvial Water Sources 2012. Flood work applications in these areas are now assessed under the Gwydir Valley FMP 2016. The Floodplain Harvesting Project’s register of interest process and potential floodplain harvesting structures were also considered when delineating the proposed boundary; however, no changes were requiredThe boundary of theLowerNamoiValley Floodplain was delineated based on the consideration of the following:Designated floodplains and floodplain development guidelinesLower NamoidesignatedFloodplain The WA 1912 was repealed in 2015 and all existing designated floodplains under this Act transitioned across to the WMAHydraulic effects of developmentThe floodplain was extended to include additional flood works that were outside the existing designated floodplain areas to meet the objectives of the Lower NamoiValley FMP and to assist with the coordination of all flood works across the extent of major flooding.Cadastral and administrative relevanceWhere appropriate, the floodplain was aligned with significant cadastral features (e.g. property, parish, county, LGA and State boundaries; roads and railways) to simplify administration and to provide clarity to water users.Planning legacy (unregulated water sharing plans (WSPs))Where appropriate, the boundary was aligned with unregulated WSP boundaries to ensure consistency with boundaries of water management plans under the WMA, ease of administration and increased clarity for water users.Floodplain harvestingThe floodplain boundary included areas identified through the Floodplain Harvesting Project’s expression of interest process for floodplain harvesting licences and potential floodplain harvesting structures. This ensures consistency with the NSW Floodplain Harvesting Policy (NSW DPI 2013), which only applies to floodplain harvesting activities on properties where all or part of that property lies within the designated floodplain.Other FMP floodplain boundariesThe Lower Namoi Valley Floodplain was aligned with FMP boundaries of the, Upper Namoi,Gwydir, and Barwon Darlingvalleys to provide consistency with other water management plan boundaries under the WMA 2000.Landscape featuresWhere appropriate, the boundary was aligned with significant landscape features, such as weirs, to assist ease of administration and to provide clarity for water users.Lidar and ADS40 DEMs and floodimaery were also used to identify landscape featrues.
Copyright Text: OEH Healthy Floodplains Unit in conjuction with DPI, Water.
Description: Used as part of the Healthy Floodplain for the Lower NamoiValleyFloodplain Management Plan(FMP).The nature and location of the management zones for the Lower Namoi Valley Floodplain was determined using hydraulic, ecological and cultural criteria as well as criteria to ensure the plan reflects current floodplain management arrangements. This approach considered the impact of existing and future development on flooding in rivers and floodplains; the flood risk to life and property; the flood connectivity of floodplain assets and the social and economic impacts of restricting flood work development. Management zones for the Floodplain Management Plan for the Lower NamoiValley Floodplain 2019.The Lower Namoi Valley FMP has 6 management zones: 1)MZ AD – Major discharge areas, defined floodways (133,700 hectares or 23% of the FMP)These areas are generally characterised by relatively high flood-flow velocity and depth (≥ 0.2 m2/s for large design flood, 1971, 4% AEP). 2)MZ AID – Major discharge areas, ill-defined floodways (21,400 hectares or 4 % of the FMP)The ill-defined floodways are major discharge areas, which are major discharge areas but where the selected depth-velocity product thresholds do not support the delineation of a defined floodway. Ill-defined floodways must have a depth velocity product of at least 0.05 m2/s for the large design flood (1971 – 4% AEP). Ill-defined floodways are the width of the upstream 3)MZ B – Flood storage and secondary flood discharge (189,600 hectares or 33% of the FMP) It is important for the conveyance of floodwater during large flood events and for the temporary pondage of floodwaters during the passage of a flood. It includes ecological assets that have a moderate level of flood dependency, and also includes cultural assets such as modified trees that are likely to only be flood connected during moderate and large floods.4)MZ C – Flood fringe and flood protected developed areas (221,800 hectares or 39 % of the FMP). MZ C also includes areas protected by flood works that are unlimited height and are not overtopped by water during moderate to large floods. The rules and assessment criteria of MZ C are less restrictive than other management zones as MZ C includes areas where flood work development is unlikely to have a significant effect on flood behaviour. Nevertheless, flood works still require an assessment and approval to protect the health of the floodplain environment.5)MZ CU – Urban areas managed by Local Council (2800 hectares or less than 1 %of the FMP)It includes parts of Narrabri and Wee Waa that are urban areas where flood risk is managed by local government authorities through flood risk management plans and studies developed in accordance with the Floodplain Development Manual (NSW Government 2005).6)MZ D – Special environmental and cultural protection zone (1500 hectares or less than 1 % of the FMP)These areas are subject to frequent inundation and have high ecological and/or cultural value.
Copyright Text: Office of Environment and Heritage: Healthy Floodplains Unit; and Waters, Wetlands and Coasts Science Branch.
Description: Hydraulic flood modelling of the large (1971) design floods in the Lower Namoi floodplain under existing development conditions was used to determine acceptable re-distribution of peak flood flows at a regional/floodplain scale. To be used when calculating the percentage redistribution potentially caused by a proposed flood work. This product should be used to help assess cumulative impacts associated with flood work development as required by the cumulative impact assessment criterion.
Copyright Text: Office of Environment and Heritage: Healthy Floodplains Unit
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Description: This spatial data represents the footprint (area enclosed by existing flood works). Existing development footprint may contain spatial delineation of levees, banks, supply channels, infrastructure protection works, roads and storages. However, where a flood work is a linear area that does not form a polygon or enclose an area, these works are not delineated in this spatial data. This may occur where a supply channel runs from the river onto a property. This area of conveyance would not be mapped unless it enclosed an area with other associated flood-work developments.Limited height works were also included. Verification of data with licensing officers is recommended. Data also indicated where the flood work was considered to be above ground and mapped as MZ C in the management zonesDepartment of Primary Industries, Water. Initial licence information extracted from DPI, Water Licence Administration System. Contributions to data refinement have been made by Office of Environment and Heritage, Healthy Floodplains Unit.
Copyright Text: Office of Environment and Heritage, Healthy Floodplains Unit and Department of Primary Industries, Water.
Description: This dataset includes ecological and cultural refinements to Management Zone A, in addition to the floodway network. These refinements were based on the flood dependency and ecological and cultural significance of assets in the floodplain. These refinements were incorporated into the Management Zone data but are provided separately like the floodway network to identify the individual components that comprise the Lower Namoi Valley Management Zones.
Copyright Text: Office of Environment and Heritage: Healthy Floodplains Unit and Waters, Wetlands and Coasts Science Branch.
Description: Priority vegetation and wetland assets to inform development of the Lower Namoi FMP floodplain management plan 2019. Refer to HFP_Source field and Reference field in the attribute table for data sources including:Eco Logical Australia. 2013. Refinement of vegetation mapping in the Namoi Catchment: Extant and pre-European. Prepared for Namoi CMA. May 2013, Eco Logical Australia. 2015. Development of a Biodiversity Prioritisation Plan for the North West LLS Region. Report prepared for North West LLS Region. June 2015, Eco Logical Australia. 2008. Namoi Wetland Assessment and Prioritisation Project. Draft report prepared for Namoi Catchment Management Authority. September 2008, Eco Logical Australia. 2013. Refinement of vegetation mapping in the Namoi Catchment: Extant and pre-European. Prepared for Namoi CMA. May 2013, Eco Logical Australia. 2015. Development of a Biodiversity Prioritisation Plan for the North West LLS Region. Report prepared for North West LLS Region. June 2015, EcoLogical Australia (2008)Vegetation Mapping for the Namoi and Borger Rivers-Gwydir CMAs: Compilation of API Datasets and Preparation of a Hierarchical Vegetation Classification. Proj No.s 125-002 & 129-002., EcoLogical Australia (2009) A Vegetation Map for the Namoi Catachemnt Management Authority. Project No. 125-004. Report prepared for Namoi CMA. June 2009, NSW Hydro Area, NSW Office of Environment and Heritage, 2015. BRG-Namoi Regional Native Vegetation Mapping. Technical Notes, NSW Office of Environment and Heritage, Sydney, Australia, Green, D and Dunkerley, G 1992. Wetlands of the Namoi Valley: Progress Report. March 1992. A progress Report to the Murray-Darling Basin Commission for the Barwon-Darling Wetland Survey, funded under the Natural Resources Management Strategy and wetlands identified by the NSW Healthy Floodplains Project mapped using contours derived from LiDAR.
Description: Used as part of the Healthy Floodplain Lower NamoiValleyFloodplain Management Plan.The Lower NamoiValleyFMP floodplain boundary, which covers 570,700 hectares, was defined to capture the floodplain areas inundated during flooding of the major rivers running between Narrabri and Walgett and to include any works that may affect floodingThe floodway network map represents those areas on the floodplain that have adequate hydraulic capacity and continuity to effectively convey flood waters. It is comprised of:a coordinated and integrated network of floodways where a significant discharge of floodwater occurs during floodsthe inundation extent of small and large design floodsareas that preserve floodplain connectivityareas that provide sufficient pondage for floodwater.The Lower Namoi floodway network is comprised of three hydraulic categories:defined floodways (133,600 ha or 24 % of the floodplain), which are areas where a significant discharge of floodwater occurs during design floods and are important for the continuity of flood flows over the floodplain ill-defined floodways (21,400 ha or four % of the floodplain), which are areas where a significant discharge of floodwater occurs during design floods. They are overland flow paths with no defined channels or riverbanks that are important for the continuity of flood flows over the floodplaininundation extent (221,700 hectares or 39 % of the floodplain), which includes areas of the floodplain that are important for the temporary storage of floodwaters during the passage of a flood and for secondary flood discharge.The remaining 189,700 hectares or about 33 % of the floodplain was outside of the inundation extent of the large design flood and was therefore not included as part of the floodway network. About half of this area is not flooded because it is protected by flood works. Design floods were selected for the Burren, Merah, Molle, Reach 2 and Narrabri model reaches of the Lower Namoi Valley FMP:· large design flood – January/February 1971 (4% AEP @ Namoi River at Mollee gauging station GS 419039)· small design flood – December 2004 (13% AEP @ Namoi River at Mollee gauging station GS 419039).A flood frequency analysis was undertaken to understand the relative size of the historic floods Hydraulic model outputs used include a depth-velocity product map from the large design flood and inundation extents of the small and large design floods.Hydraulic criteria for mapping the floodway network are summarised in the table below.Hydraulic categoryCriteriaMajor Discharge Areas, Defined FloodwaysMajor discharge areas that have a depth-velocity product of ≥ 0.2 m2/s for the large design flood (1971 – 4% AEP).Floodplain connectivity was provided for by incorporating:parts of the small design flood extent (2004 – 13% AEP)for and/orfloodplain areas that have a depth-velocity product of ≥ 0.05 m2/s for the large design flood (1971 – 4% AEP).To ensure that conditions on the ground are adequately represented, the above criteria were checked against the following additional data:flood aerial photography and satellite imageryspatial watercourse layers, topographical mapping, ADS DEM and LiDARprevious floodplain management plans and development guidelineslocal knowledge obtained from floodplain communities and floodplain/environmental managers.Major Discharge Areas, Ill Defined FloodwaysMajor discharge areas that have a depth-velocity product of <0.05 m2/s for the large design flood (1971 – 4% AEP).The location of ill-defined floodways is guided by:areas with a depth-velocity product of <0.05 m2/s for the large design flood (1971 – 4% AEP) and/orflood imagery and/orlocal knowledge and/orparts of the small design flood extent (2004 – 13% AEP).The width of ill-defined floodways is determined by the width of the upstream defined floodway and a maximum 500 metre buffer either side of this floodway (minimum width is one kilometre).To ensure that conditions on the ground are adequately represented, the above criteria were checked against the following additional data:flood aerial photography and satellite imageryspatial watercourse layers, topographical mapping, ADS DEM and LiDARprevious floodplain management plans and development guidelineslocal knowledge obtained from floodplain communities and floodplain/environmental managers.Flood Storage and Secondary Flood Discharge AreasFlood storage and secondary flood discharge areas of the floodplain:are areas not already identified as an ill-defined or defined floodway and areincluded within the extent of the large design flood (1971 – 4% AEP) or areenclosed by existing Part 8 approved flood works that are overtopped during moderate to large floods.To ensure that conditions on the ground are adequately represented, the above criteria were checked against the following additional data:flood aerial photography and satellite imagery from design floodsspatial watercourse layers, topographical mapping, ADS DEM and LiDARprevious floodplain management plans and development guidelineslocal knowledge obtained from floodplain communities and floodplain/environmental managers.Areas outside floodway network (known as Flood Fringe and Flood Protected Areas)Areas outside of the floodway network include the flood fringe areas of the floodplain which have not been mapped as floodways or flood storage and secondary flood discharge areas. These areas of the floodplain are:outside the extent of the large design flood (1971 –4% AEP) and/or are enclosed by existing Part 8 approved flood works that are not designed to be overtopped during flooding To ensure MZ C represents on-ground conditions, the above criteria were road tested against the following additional data: flood aerial photography and satellite imagery from design floods spatial watercourse layers, topographical mapping, ADS DEM and LiDAR previous floodplain management plans and development guidelines local knowledge obtained from floodplain communities and floodplain/environmental managers.
Copyright Text: Office of Environment and Heritage: Healthy Floodplains Unit
Description: The Border Rivers Valley floodplain, which covers 558,440 hectares, was defined to capture the floodplain areas inundated during flooding of the major rivers and to include any works that may affect flooding. Defining the Border Rivers Valley Floodplain boundary was based on the consideration of the following:• Designated floodplains and floodplain development guidelinesExisting and potential floodplain developments in the Border Rivers Valley Floodplain were identified from the following existing floodplain areas designated under Part 8 of the WA 1912: o Lower Macintyre (Yelarbon Crossing to Mungindi) floodplain which was designated under Section 166 Part 8 of the WA 1912 on 31 July 1985o Floodplain development guidelines for the Macintyre River and Whalan Creek floodplains between Boggabilla and Mungindi (WRC 1981)The existing Lower Macintyre (Yelarbon Crossing to Mungindi) designated floodplain was used as the basis for the Border Rivers Valley Floodplain to capture existing and potential floodplain developments within the floodplain.Where appropriate, the floodplain was extended to include the floodplain development guidelines for the Macintyre River and Whalan Creek floodplains between Boggabilla and Mungindi (WRC 1981).• Hydraulic effects of developmentThe floodplain was extended to include additional flood works located outside the existing designated floodplain area to meet the objectives of the Border Rivers Valley FMP and to assist with the coordination of all flood works across the extent of major flooding.• Cadastral and administrative relevanceWhere appropriate, the floodplain was aligned with significant cadastral features (e.g. state, property, parish, county and LGA boundaries, roads and railways) to simplify administration and to provide clarity to water users.• Planning legacy (unregulated WSPs)Where appropriate, the boundary was aligned with relevant unregulated WSP boundaries to ensure consistency with other boundaries for water management plans under the WM ACT 2000, ease of administration and increased clarity for water users.• Floodplain harvestingThe floodplain boundary included areas identified through the Floodplain Harvesting Program’s expression of interest process for floodplain harvesting licences and potential floodplain harvesting structures. This will ensure consistency with the NSW Floodplain Harvesting Policy (NSW DPI 2013), which only applies to floodplain harvesting activities on properties where all or part of that property lies within the designated floodplain.• Other Valley FMP floodplain boundariesThe Border Rivers Valley Floodplain was aligned with the boundaries of the Gwydir Valley FMP 2016 and the Barwon-Darling Valley FMP 2017 to provide consistency with other water management plan boundaries under the WM ACT 2000.• Landscape featuresWhere appropriate, the boundary was aligned with significant landscape features, such as weirs, to assist ease of administration and to provide clarity for water users. The overall extent of boundary change when compared to the existing designated floodplain was the addition of approximately 113,840 hectares in some areas and the subtraction of approximately 62,990 hectares in other areas
Copyright Text: NSW Department of Planning, Industry and Environment: Healthy Floodplains Unit, Biodiversity and Conservation Branch
Description: Used as part of the Healthy Floodplain for the Border Rivers ValleyFloodplain Management Plan(FMP).The nature and location of the management zones proposed for the Border Rivers Valley Floodplain was determined using hydraulic, ecological and cultural criteria as well as criteria to ensure the plan reflects current floodplain management arrangements. The approach for developing the management zones considered the impact of existing and future development on flooding in rivers and floodplains; the flood risk to life and property; the flood connectivity of floodplain assets and the social and economic impacts of restricting flood work development.The Border Rivers Valley FMP 2020contains five different management zones:1. Management Zone A (MZ A) – Major discharge areas, defined floodways (124,359 ha or 23% of the FMP). These areas are generally characterised by relatively high flood-flow velocity and depth (DVP ≥ 0.3 m2/s for large design flood, 1976, 1.3% AEP). 2. Management Zone C (MZ B) – Flood storage and secondary flood discharge (285,755 ha or 51% of the FMP). It is important for the conveyance of floodwater during large flood events and for the temporary pondage of floodwaters during the passage of a flood. It includes ecological assets that have a moderate level of flood dependency, and also includes cultural assets such as modified trees that are likely to only be flood connected during moderate and large floods.3. Management Zone C (MZ C) — Flood fringe and flood protected developed areas (145,590 ha or 26 % of the FMP). MZ C also includes areas protected by flood works that are unlimited height and are not overtopped by water during moderate to large floods. The rules and assessment criteria of MZ C are less restrictive than other management zones as MZ C includes areas where flood work development is unlikely to have a significant effect on flood behaviour. Nevertheless, flood works still require an assessment and approval to protect the health of the floodplain environment.4. Management Zone CU (MZ CU) – Urban areas managed by Local Council (600 ha or less than one % of the floodplain). It includes parts of urban areas where flood risk is managed by local government authorities through flood risk management plans and studies developed in accordance with the Floodplain Development Manual (NSW Government 2005).5. Management Zone D (MZ D) – Special environmental and cultural protection zone (153 ha or less than one % of the floodplain). These areas are subject to frequent inundation and have high ecological and/or cultural value.
Copyright Text: NSW Department of Planning, Industry and Environment: Healthy Floodplains Unit, Biodiversity and Conservation Branch; and Waters, Wetlands and Coasts Science Branch,
Description: Hydraulic flood modelling of the large (1976) design floods in the Border Rievrs floodplain under existing development conditions was used to determine acceptable re-distribution of peak flood flows at a regional/floodplain scale. To be used when calculating the percentage redistribution potentially caused by a proposed flood work.This product should be used to help assess cumulative impacts associated with flood work development as required by the cumulative impact assessment criterion
Copyright Text: NSW Department of Planning, Industry and Environment: Healthy Floodplains Unit Biodiversity; and Conservation Branch and Waters, Wetlands and Coasts Science Branch,
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Description: This spatial data represents the footprint (area enclosed by existing flood works) as of October 2019. Existing development footprint may contain spatial delineation of levees, banks, supply channels, infrastructure protection works, roads and storages. However, where a flood work is a linear area that does not form a polygon or enclose an area, these works are not delineated in this spatial data. This may occur where a supply channel runs from the river onto a property. This area of conveyance would not be mapped unless it enclosed an area with other associated flood-work developments. Limited height works were also included. Verification of data with licensing officers is recommended. Data also indicated where the flood work was considered to be above ground and mapped as MZ C in the management zones. Department of Primary Industries, Water. Initial licence information extracted from DPI, Water Licence Administration System. Contributions to data refinement have been made by Office of Environment and Heritage, Healthy Floodplains Unit
Copyright Text: Department of Primary Industries, Water and NSW Department of Planning, Industry and Environment: Healthy Floodplains
Description: This dataset includes ecological and cultural refinements to Management Zone A, in addition to the floodway network. These refinements were based on the flood dependency and ecological and cultural significance of assets in the floodplain. These refinements were incorporated into the Management Zone data but are provided separately like the floodway network to identify the individual components that comprise the Border Rivers Valley Management Zones. This spatial data includes ecological and cultural refinements to Management Zone A where the primary basis is ecological or cultural. These areas are important for flood connectivity to ecological and cultural assets. It is not specified whether the addition was based on ecological or cultural assets due to data sensitivity of the cultural assets. Location of these Eco-Cultural Assets aided in identifying the location of management zones for the Border Rivers Valley Management Plan. It is not specified whether the addition was based on ecological or cultural assets due to data sensitivity of the cultural assets. Location of these Eco-Cultural Assets aided in identifying the location of management zones for the Border Rivers Floodplain Management Plan
Copyright Text: NSW Department of Planning, Industry and Environment: Healthy Floodplains Unit Biodiversity; and Conservation Branch and Waters, Wetlands and Coasts Science Branch,
Description: Priority vegetation and wetland assets to inform development of the Border Rivers FMP floodplain management plan 2019. Composite vegetation and wetlands map used to inform development of the Border Rivers Floodplain Management Plan Zones derived from various sources. This dataset contains both flood dependent vegetation and wetlands identified from previous studies Ecological assets were:-identified using best-available spatial data-grouped using information on their optimum watering requirements-prioritised to select the assets that best represent biodiversity on the floodplain. This shapefile is a composite vegetation map derived from various sources (see Metadata/Data Source/Report citation). Contains only flood-dependent vegetation that were used as the basis for ecological assets in the Border Rivers Valley FMP. Refer to HFP_Source field and Reference field in the attribute table for data sources including:1. NSW Office of Environment and Heritage, 2015. BRG-Namoi Regional Native Vegetation Mapping. Technical Notes, NSW Office of Environment and Heritage, Sydney, Australia., 2. EcoLogical Aust, 2009. Upgrade of Vegetation Mapping in the Border Rivers-Gwydir Catchment., 3. EcoLogical Australia (2015) Development of a Biodiversity Prioritisation Plan for the North West LLS., 4. Hudson & Bacon (2009) Culturally significant lagoons and salt affected sites project., 5. Landuse data (Lake, Marsh/wetland., 6. HydroArea. 7. Wetlands mapped by Healthy Floodplains Team using LiDAR.Refer to WSP field to identify significant identified lagoons and wetlands from Schedule 5 of the WSP NSW Border Rivers Unreg & Alluvial Water Sources 2012
Copyright Text: NSW Department of Planning, Industry and Environment: Healthy Floodplains Unit Biodiversity; and Conservation Branch and Waters, Wetlands and Coasts Science Branch,
Description: Used as part of the Healthy Floodplain Border Rivers ValleyFloodplain Management Plan.he floodway network was the hydraulic basis for determining the management zones, rules and assessment criteria of the Border Rivers Valley FMP. The floodway network is based on two-dimensional (2D) hydraulic modelling (using TUFLOW software), existing floodway networks in current FMPs, stream orders, flood imagery, ADS imagery, LiDAR and ADS DEMs, topographical mapping and slope. The floodway network map represents those areas on the floodplain that have adequate hydraulic capacity and continuity to effectively convey flood waters. The Border Rivers floodway network is comprised of two hydraulic categories:• a coordinated and integrated network of floodways where a significant discharge of floodwater occurs • the inundation extent of small and large design floods, which includes areas of the floodplain that are important for the temporary storage of floodwaters during the passage of a flood and for secondary flood discharge, and that preserve floodplain connectivity.Two design floods were selected for the Border Rivers Valley FMP:• large design flood – February 1976 (approximately 1% AEP @ Mungindi and 1.3% AEP @ Boggabilla), and• small design flood – 13% AEP flood (equivalent to the January/February 2013 flood at Mungindi)A flood frequency analysis was undertaken to assist with the selection of the design floods. The flood frequency analysis was used to determine the relationship between peak flood discharge at a location of interest and the likelihood that a flood event of that size or greater would occur. This analysis uses available flow records, which may include records from when the flooding regime was relatively natural, as well as information that encompasses the existing flooding regimes. The Border Rivers floodway network is comprised of 2 hydraulic categories:1) floodways (122,813 ha or 22 % of the floodplain), which are areas where a significant discharge of floodwater occurs during design floods and are important for the continuity of flood flows over the floodplain. 2) Inundation extent ( 289,454 ha or 52% of the floodplain), which includes areas of the floodplain that are important for the temporary storage of floodwaters during the passage of a flood and for secondary flood discharge.The remaining 146,178 or about 26 % of the floodplain was outside of the inundation extent of the large design flood and was therefore not included as part of the floodway network. Hydraulic model outputs used include a depth-velocity product (DVP) map from the large design flood and inundation extents of the small and large design floods.
Copyright Text: NSW Department of Planning, Industry and Environment: Healthy Floodplains, Unit Biodiversity and Conservation Branch; and Waters, Wetlands and Coasts Science Branch,
Description: The rural Floodplain Management Plan for the Macquarie Valley Floodplain 2020 applies to the area defined as the Macquarie Valley Floodplain, which covers 1.24 million hectares. This area is declared to be a floodplain under the Water Management (General) Regulation 2011. This boundary captures the floodplain areas inundated during flooding of major rivers, and any flood works that may affect flooding. The Macquarie Valley Floodplain boundary was delineated based on the consideration of the following:Designated floodplainsExisting and potential floodplain developments in the Macquarie Valley Floodplain were identified from the following floodplain areas designated under Part 8 of the Water Act1912:Lower Macquarie floodplain (designated in 1985)Macquarie River floodplain (designated in 2008 as part of the Macquarie River (Narromine to Oxley Station) FMP 2008) The Water Act 1912 was repealed in 2015 and all existing designated floodplains under this Act transitioned across to the Water Management Act 2000.Hydrology of the Macquarie RiverFloodplain areas influenced primarily by the hydrology of the Macquarie River were included within the Macquarie Valley FMP floodplain boundary and were determined by examining the following information:flood imagery of the 1990 and 2010 floodsMacquarie Valley Floodplain Atlas (Sinclair Knight and Partners Pty Ltd 1984b)DPIE EES inundation mapping (Fisher et al. 2016; Thomas et al. 2015; Thomas et al. 2010)2008, 2014 and 2015 LiDAR Digital Elevation Models (DEMs)hydrodynamic modelling of the Macquarie River and Marthaguy Creek flows.The floodplain was extended from the Macquarie River floodplain for the Macquarie River (Narromine to Oxley Station) FMP 2008 to include the Macquarie Marshes and the effluent creek system. Part of the floodplain of Marthaguy Creek, a tributary of the Macquarie River, was also included because of significant flooding during the December 2010 flood and the contribution of substantial inflows to the Macquarie River. Areas considered not to be predominantly influenced by the hydrology of the Macquarie River, including the lower Bogan and Castlereagh floodplain, were not included in the Macquarie Valley Floodplain. Areas of high ground considered to be above the level of flood-liable land were determined from LiDAR-derived DEMs and contour mapping. These areas were also checked against available flood imagery and flood-dependent vegetation mapping. High ground areas including Mt Foster, Mt Harris and other hills were extracted from the floodplain.Hydraulic effects of developmentThe floodplain area was extended to include flood works outside existing designated floodplain areas, to meet the objectives of the Macquarie Valley FMP and assist with the coordination of all flood works across the extent of major flooding. Cadastral featuresWhere appropriate, the floodplain was aligned with significant cadastral features (e.g. property, parish, county and Local Government Area (LGA)) to simplify administration and provide clarity to water users. Planning legacy (unregulated water sharing plans)The Macquarie Valley Floodplain is entirely within the water management area of the Water Sharing Plan (WSP) for the Macquarie Bogan Unregulated and Alluvial Water Source(2012a). However, alignment of the floodplain boundary with the water management areas of the WSP was not considered important by the Macquarie Technical Advisory Group, as these areas are not delineated according to flooding characteristics. Floodplain harvestingThe floodplain boundary included areas identified in the Floodplain Harvesting Project’s expression of interest process for floodplain harvesting licences and potential floodplain harvesting structures. This will ensure consistency with the NSW Floodplain Harvesting Policy (NSW DPI 2013), which only applies to floodplain harvesting activities on properties where all or part of a property lies within the designated floodplain. Other rural FMP floodplain boundariesThe Macquarie Valley Floodplain was aligned with the boundary for the Barwon–Darling Valley FMP 2017 (NOW 2017) to provide consistency with other boundaries for water management plans under the Water Management Act 2000.Public infrastructure featuresWhere appropriate, the boundary aligns with public infrastructure such as railways and State and Council roads to simplify administration.Urban floodplain management arrangementsWhere appropriate, the boundary aligns with existing floodplain management arrangements in urban areas, such as a Flood Study, Floodplain Risk Management Study (FRMS) and Floodplain Risk Management Plan (FRMP). Amendments to the boundary were made based on information from councils regarding the extent of flood risk management planning arrangements in urban areas.
Copyright Text: The Environment, Energy and Science Group (Healthy Floodplains Team) in conjunction with the Water Group within the Department of Planning, Industry and Environment.
Description: The nature and location of the management zones for the Macquarie Valley Floodplain were determined using hydraulic, ecological and cultural criteria, as well as criteria to ensure the plan reflects previous floodplain management arrangements. This approach considered the impact of existing and future development on flooding in rivers and floodplains; the flood risk to life and property; the flood connectivity of floodplain assets; and the social and economic impacts of restricting flood work development. The above approach resulted in six management zones for the Floodplain Management Plan for the Macquarie Valley Floodplain 2020:Macquarie Management Zone A – major discharge areas (204,800 hectares (ha) or 17% of the floodplain)Macquarie Management Zone BH – major discharge areas in higher floodway areas (18,500 ha or 2% of the floodplain)Macquarie Management Zone B – flood storage and secondary flood discharge areas (314,900 ha or 25% of the floodplain)Macquarie Management Zone C – flood fringe and flood-protected developed areas (626,100 ha or 50% of the floodplain)Macquarie Management Zone CU – urban areas managed by local councils (6,000 ha or less than 1% of the floodplain)Macquarie Management Zone D – special environmental and cultural protection areas (70,200 ha or 6% of the floodplain)
Copyright Text: NSW Department of Planning, Industry and Environment: Healthy Floodplains Unit, Biodiversity and Conservation Branch; and Waters, Wetlands and Coasts Science Branch.
Description: Peak discharge of the August 1990 large design flood (2.9% AEP at the Macquarie River at Narromine gauging station – 421006) under modelled existing development conditions in the Macquarie Valley Floodplain. The locations are the four transects running in a general east west direction across the floodplain. Each location is split into several sections running generally perpendicular to the direction of flow and/or followinga road. The peak discharge (‘Q_value’) occurring in each section of the floodplain is reported as a total flow in cubic metres per second. The total flow typically includes flow within the river, as well as across the floodplain areas adjacent to the river.For flood work applications that require a supporting Flood Study Report, the rural Floodplain Management Plan for the Macquarie Valley Floodplain 2020 typically requires consideration of the changes to peak flood flow distribution at a regional/floodplain scale. This is calculated as the percentage redistribution potentially caused by a proposed flood work. This information is used to ensure any redistribution of peak flood flows at a regional/floodplain scale is within acceptable limits (as specified in cumulative impact assessment criteria in the rural Floodplain Management Plan for the Macquarie Valley Floodplain 2020).
Copyright Text: The Environment, Energy and Science Group (Healthy Floodplains Team) in conjunction with the Water Group within the Department of Planning, Industry and Environment.
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Description: This spatial extent of the floodplain areas to which DPIE – EES North West requests referral of flood work applications to minimise the Key Threatening Process (KTP) – Alteration to the natural flow regimes of rivers and streams and their floodplains and wetlands listed on Schedule 4 of the BC Act. The spatial extent is defined by Management Zone D and ecological/cultural refinements to Management Zones A, BH and B. Written advice and/or recommendations are to be sought by the assessing officer from DPIE – EES North West for assessment of flood work applications located in these critical areas.
Copyright Text: The Environment, Energy and Science Group (Healthy Floodplains Team) in conjunction with the Water Group within the Department of Planning, Industry and Environment.
Description: Priority vegetation and wetland assets to inform development of the rural Floodplain Management Plan for the Macquarie Valley Floodplain 2020. Refer to HFP_Source field and Reference field in the attribute table for data sources including:CentWestLachSVM_v1p4_PCT_E_4468 (NSW Office of Environment and Heritage, 2015. BRG-Namoi Regional Native Vegetation Mapping. Technical Notes, NSW Office of Environment and Heritage, Sydney, Australia), Macquarie Marshes_2013_E_4892 (Bowen, S., and Fontaine (2014) 2013 Vegetation Map of the Macquarie Marshes. Office of Environment and Heritage, Sydney, NSW) and WesternSVM_v1p0 (OEH - pending technical report).
Description: This data represents the footprint of approved flood work development as of April 2020 within the Macquarie Valley Floodplain. This data may spatially represent levees, banks, supply channels, infrastructure protection works, roads and storages that fully enclose an area or that enclose an area by meeting with: a roadanother approved flood work(s)natural high ground.The footprint was digitised using work plan maps provided by WaterNSW; however, further verification with licensing officers is recommended. The data indicates approved flood works that are above ground and mapped as Management Zone C. Limited height works that may not be mapped as Management Zone C are also included.The data also indicatesthe flood work approval number and the date the approval was issued.Flood works that are linear and do not enclose an area are not represented (e.g. a supply channel running from the river onto a property). Works such as centre pivots are not represented.
Copyright Text: The Environment, Energy and Science Group (Healthy Floodplains Team) in conjunction with the Water Group within the Department of Planning, Industry and Environment.
Description: This dataset includes the spatial extent of ecological and cultural refinements made to Management Zone A, Management Zone BH and Management Zone B within the rural Floodplain Management Plan for the Macquarie Valley Floodplain 2020. These refinements were based on the flood dependency and ecological and cultural significance of assets in the floodplain. These areas are important for flood connectivity to ecological and cultural assets. It is not specified whether the addition was based on ecological or cultural assets due to data sensitivity of the cultural assets.
Copyright Text: The Environment, Energy and Science Group (Healthy Floodplains Team) in conjunction with the Water Group within the Department of Planning, Industry and Environment.
Description: The floodway network is the hydraulic basis for the management zones, rules and assessment criteria of the rural Floodplain Management Plan for the Macquarie Valley Floodplain2020. The floodway network map represents floodplain areas that have adequate hydraulic capacity and continuity to effectively convey flood waters. It is comprised of:a coordinated and integrated network of floodways where a significant discharge of floodwater occurs during floodsthe inundation extent of small and large design floodsareas that preserve floodplain connectivityareas that provide sufficient pondage for floodwater.Three hydraulic categories are mapped in the floodway network:floodways (190,900 hectares (ha) or 15% of the floodplain), which are areas where a significant discharge of floodwater occurs during the November 2000 large design flood (8% AEP at Narromine gauging station) upstream of Warren and the Oxley Highway, and the August 1990 large design flood (3% AEP at Narromine gauging station) downstream of Warren and the Oxley Highwayhigh-level floodways (17,300 ha or 1% of the floodplain), which are areas upstream of Warren and the Oxley Highway that are important for conveying and temporary storage of floodwaters, and where a significant discharge of floodwater occurs during the August 1990 large design flood and larger eventsinundation extent (392,100 ha or 32% of the floodplain), including areas of the floodplain that are important for the temporary storage of floodwaters during the passage of a flood.The floodway network was determined using:Hydraulic model outputsdepth-velocity product maps for the large design floods (areas with a depth-velocity product threshold of ≥0.1m2/s were categorised as floodways)discharge and velocity values along flow pathsinundation extent for the small and large design floodsOther dataflood aerial photography and satellite imageryspatial watercourse layers and topographical mappingprevious rural floodplain management plan and guidelineslocal knowledge obtained from floodplain communities and floodplain managers.Approximately 648,100 ha, or 52% of the Macquarie Valley Floodplain, is outside the inundation extent of thesmall andlarge design floods and/or an urban area where there is either a Flood Study, a floodplain risk management study, a floodplain risk management plan or the area is protected by a flood mitigation work, such as a town levee.These floodplain areas arenot part of the floodway network.
Copyright Text: The Environment, Energy and Science Group (Healthy Floodplains Team) in conjunction with the Water Group within the Department of Planning, Industry and Environment.