Protecting Flood Connectivity in the Upper Namoi River Valley Floodplain to Enhance the Health and Resilience of Floodplain Wetlands and Riverine Ecosystems
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Protecting flood connectivity in the Upper Namoi River Valley Floodplain to enhance the health and resilience of floodplain wetlands and riverine ecosystems Namoi River, Boggabri, New South Wales. 27 June 2019. Simon Hunter (DPIE) Sharp-tailed Sandpiper, Calidris acuminata, Goran Lake. 20 April 2013. Michael Dahlem Mooki River, Breeza, New South Wales. 27 June 2019. Simon Hunter (DPIE) Simon J Hunter Water and Wetlands Team, Environment, Energy and Science Department of Planning, Industry & Environment. Sydney, New South Wales, Australia Insert your logo Brisbane, Australia | 20-24 October 2019 Upper Namoi Valley Floodplain Management Plan 2019 ▪ Developed under NSW Healthy Floodplains Project – UPPER NAMOI VALLEY FLOODPLAIN funded by Australian Government’s Sustainable Rural MANAGEMENT PLAN (2019 – 2029) Water Use & Infrastructure Program as part of the implementation of the Murray-Darling Basin Plan in NSW ▪ Detailed legal instrument and spatial floodplain management plan covering 588,600 hectares developed under the Water Management Act 2000 ▪ Commenced on 6th June 2019 and is due for extension or replacement on 6th June 2029 Insert your logo Brisbane, Australia | 20-24 October 2019 Upper Namoi Valley Floodplain Management Plan 2019 GWYDIR VALLEY DRAFT BORDER FLOODPLAIN RIVERS VALLEY MANAGEMENT FLOODPLAIN PLAN (2016 – 2026) MANAGEMENT PLAN ▪ Developed under NSW Healthy Floodplains Project – funded by Australian Government’s Sustainable Rural BARWON-DARLING VALLEY FLOODPLAIN Water Use & Infrastructure Program as part of the MANAGEMENT PLAN (2017 – 2027) implementation of the Murray-Darling Basin Plan in NSW UPPER NAMOI VALLEY FLOODPLAIN MANAGEMENT PLAN (2019 – 2029) ▪ Detailed legal instrument and spatial floodplain management plan covering 588,600 hectares developed under the Water Management Act 2000 ▪ Commenced on 6th June 2019 and is due for extension or replacement on 6th June 2029 DRAFT MACQUARIE VALLEY FLOODPLAIN MANAGEMENT DRAFT LOWER NAMOI PLAN VALLEY FLOODPLAIN MANAGEMENT PLAN Insert your logo Brisbane, Australia | 20-24 October 2019 The Upper Namoi River Valley Floodplain – an important link to downstream environments and the Barwon-Darling River system GWYDIR VALLEY FLOODPLAIN MANAGEMENT UPPER NAMOI PLAN (2016 – 2026) VALLEY FLOODPLAIN MANAGEMENT PLAN (2019 – 2029) Namoi River BARWON-DARLING VALLEY FLOODPLAIN MANAGEMENT PLAN (2017 – 2027) DRAFT LOWER NAMOI VALLEY FLOODPLAIN MANAGEMENT PLAN LIVERPOOL PLAINS GORAN LAKE Insert your logo Brisbane, Australia | 20-24 October 2019 Uncoordinated flood work development may adversely affect wetlands and their resilience ACCESS ROADS Boggabri If built in the wrong location flood works can alter flood connectivity: ▪ Isolate wetlands from overland flooding by The Flood Hill obstructing flow paths resulting in declined condition and resilience ACCESS ROADS WATER SUPPLY CHANNELS WATER STORAGES ▪ Redistribute flood flows away from flood-dependent assets Driggle Draggle Creek ▪ Increase flooding duration of ecological assets Deadmans Gully exceeding their water requirements ACCESS ROADS ▪ Restrict native fish passage and opportunities for migration Insert your logo Brisbane, Australia | 20-24 October 2019 Strategy for coordinating flood work development to maintain flood connectivity to ecological assets Special protection zone Plan objective for ecologically significant areas To maintain flood connectivity to wetlands, other floodplain ecosystems, and areas of groundwater recharge in the Upper Namoi River floodplain Strategy to coordinate flood work development ▪ Identify flood-dependent ecological assets Management zones protect connectivity ▪ Establish management zones for coordinating Lateral flood work development with rules and connectivity assessment criteria for the granting or amending of flood work approvals in the floodplain Insert your logo Brisbane, Australia | 20-24 October 2019 Identification of flood dependent ecological assets of the Upper Namoi River Valley floodplain Wetlands Semi-permanent wetland Floodplain wetland (Flood-dependent shrubland wetlands) Wetland sites from previous studies* *Green and Dunkerley (1992) Wetlands of the Namoi Valley Department of Natural Resources (DNR) Caroona – Breeza Floodplain Management Plan (2006), Office of Environment and Heritage (OEH) & Office of Water (OEH) (2012) Warrah Creek Floodplain Management Plan Other floodplain ecosystems Flood-dependent Forest/woodland (wetlands) Flood-dependent woodland Insert your logo Brisbane, Australia | 20-24 October 2019 Hydraulic modelling helped delineate floodways for the Upper Namoi Valley Floodplain Management Plan 2019 HYDRAULIC MODEL BOGGABRI TO NARRABRI ▪ A total of 11 hydraulic models were used to determine the floodway network (MIKE 11, MIKE 21 and RORG) ▪ Two new two-dimensional models (the Yarraman and Boggabri to Narrabri models) were created covering 68,600 and 24,000 hectares of the floodplain HYDRAULIC MODEL YARRAMAN ▪ Hydraulic models combined with flood aerial photography, satellite imagery, LiDAR and ADS40 DEM were used to delineate defined floodways and ill-defined floodways Water depth - velocity High DVP Low DVP Insert your logo Brisbane, Australia | 20-24 October 2019 Landsat satellite imagery of flooding of the Upper Namoi River Valley floodplain in 2000 ▪ Landsat 7 satellite imagery of flooding (23 November – 2 December 2000) ▪ Examine flow paths and historical patterns of flood connectivity to wetlands of the Upper Namoi River Valley floodplain ▪ Validate floodway network mapped for the Upper Namoi River Valley floodplain to ensure accuracy Insert your logo Brisbane, Australia | 20-24 October 2019 Ecological criteria to ensure flood connectivity is maintained to flood- dependent ecological assets of the Upper Namoi River floodplain Fish passage Assessment criteria for flood work applications Silver Perch (V, ce) Olive Perchlet (E) Purple Spotted Gudgeon (E) Eel tailed catfish (E) Flathead galaxias (CE) A flood work approval will not be granted unless the Bidyanus bidyanus Ambassis agassizii Mogurnda adspersa Tandanus tandanus Galaxias rostratus flood work is constructed to maintain adequate flood CE = Critically endangered, E = Endangered population, V = Vulnerable (NSW Fisheries Management Act 1994) connectivity to facilitate fish passage ce = Critically endangered (Environment Protection and Biodiversity Act 1999) Semi-permanent wetlands* Shallow freshwater wetland sedgeland (PCT 53) Entire mapped spatial extent incorporated within : A flood work approval will not be granted unless Sedgeland fen wetland of spring-fed or runoff-fed creeks (PCT 361) the flood work is constructed Defined Floodways ^ to maintain adequate flood connectivity Riparian sedgeland rushland wetland (PCT 400) to ecological assets listed in Schedule 1 of the Special Protection Areas ^ Water Couch marsh grassland wetland (PCT 204) Floodplain Management Plan for the Upper Namoi Valley Floodplain* *Includes billabongs and lagoons of the Upper Namoi floodplain fed by floodwater Defined Floodways ^ Floodplain wetlands Flood Storage and Secondary Flood Discharge Areas River Cooba swamp wetland (PCT 241) Mapped Flood Fringe Areas Forest/woodland wetlands spatial extent River Red Gum riparian tall woodland / open forest wetland (PCT 78) hydraulically connected to : Special Protection Areas ^ Increasing requirement for flooding for requirement Increasing River Oak - Rough-barked Apple - red gum - box riparian tall woodland (wetland) (PCT 84) Defined Floodways ^ *under a range of flood scenarios including, at a minimum, scenarios for the relevant small and large design floods Black Tea-tree - River Oak - Wilga riparian low forest/shrubland wetland (PCT 112) Special Protection Areas ^ ^ Only flood works that are minor in nature are permitted. These Red gum - Rough-barked Apple +/- tea tree sandy creek woodland flood works are unlikely to impact flooding patterns (wetland) (PCT 339) PCT - NSW Plant Community Type Insert your logo Brisbane, Australia | 20-24 October 2019 Integration of ecological criteria to protect Upper Namoi River Valley floodplain & wetland connectivity Airborne Digital Sensor (ADS) Boggabri Image 16/8/11 Semi-permanent wetlands Shallow freshwater wetland sedgeland in depressions on floodplains on inland alluvial plains and floodplains (PCT 53) The Flood Water Couch marsh grassland wetland of frequently flooded Hill inland watercourses (PCT 204) Broadwater Forest/woodland wetlands BroadwaterLagoon Lagoon River Red Gum riparian tall woodland / open forest wetland in the Driggle Draggle Nandewar Bioregion and Brigalow Belt South Bioregion (PCT 78) Creek Black Tea-tree - River Oak - Wilga riparian low forest/shrubland Deadmans Gully wetland of rich soil depressions in the Brigalow Belt South Bioregion (PCT 112) PCT = NSW Plant Community Type Insert your logo Brisbane, Australia | 20-24 October 2019 Integration of LiDAR data to determine Upper Namoi River Valley floodplain & wetland connectivity LiDAR Digital Elevation BoggabriBoggabri Model (DEM) Semi-permanent wetlands Shallow freshwater wetland sedgeland in depressions on floodplains on inland alluvial plains and floodplains (PCT 53) The Flood Water Couch marsh grassland wetland of frequently flooded Hill inland watercourses (PCT 204) Broadwater Forest/woodland wetlands Lagoon River Red Gum riparian tall woodland / open forest wetland in the Nandewar Bioregion and Brigalow Belt South Bioregion (PCT 78) BroadwaterDriggle Draggle LagoonCreek Black Tea-tree - River Oak - Wilga riparian low forest/shrubland Deadmans Gully wetland