Serious and irreversible impacts of development on biodiversity

Serious and irreversible impacts of development are determined to protect threatened species, ecological communities, populations and habitat.

The concept of serious and irreversible impacts is fundamentally about protecting threatened entities that are most at risk of extinction from potential development. The Biodiversity Offsets Scheme recognises that there are some types of serious and irreversible impacts that the community expects will not occur except where the consent authority considers that this type of impact is outweighed by the social and economic benefits that the development will deliver to the State.

Effect of a serious and irreversible impact

The following table sets out the effect of a serious and irreversible impact for different types of development and activities (if they require assessment under the Biodiversity Offsets Scheme):

Type of development or activity

Effect of serious and irreversible impacts

  • Clearing proposals
  • Part 4 development (that is not State Significant Development or State Significant Infrastructure)

The approval authority must not grant approval if they determine the proposal is likely to have a serious and irreversible impact on biodiversity values.

  • State Significant Development
  • State Significant Infrastructure
  • Part 5 activities (where a proponent chooses to opt in to the Biodiversity Offsets Scheme)
  • Biodiversity Certification

The approval authority can approve a proposal which is likely to have serious and irreversible impacts.

The approval authority must take those impacts into consideration and determine whether there are any additional and appropriate measures that will minimise those impacts if approval is to be granted.

Deciding whether an impact is serious and irreversible

The approval authority is responsible for deciding whether an impact is serious and irreversible. This decision is to be made in accordance with principles set out in clause 6.7 of the Biodiversity Conservation Regulation 2017.

The Guidance to assist a decision-maker to determine a serious and irreversible impact includes criteria and supporting information to assist with the application of these principles.

Information about serious and irreversible impacts will be included in the Biodiversity Assessment Report for the proposal. This report must be prepared by an accredited assessor using the Biodiversity Assessment Method.

The current list of species (and their habitat) and threatened ecological communities that are at risk of a serious and irreversible impact can be viewed below or searched in the BioNet Threatened Biodiversity Data Collection. The list is updated periodically (approximately quarterly). Accredited assessors and subscribing local government officers are notified when changes occur to the list in BAM Assessor updates and Biodiversity Offsets Scheme Local Government updates. To receive Local Government updates, subscribe to the mailing list.

Ecological communities Principle
  1 2 3 4
Agnes Banks Woodland in the Sydney Basin Bioregion  
Allocasuarina luehmannii Woodland in the Riverina and Murray-Darling Depression Bioregions    
Araluen Scarp Grassy Forest in the South East Corner Bioregion      
Artesian Springs Ecological Community in the Great Artesian Basin    
Blue Gum High Forest in the Sydney Basin Bioregion  
Blue Mountains Basalt Forest in the Sydney Basin Bioregion      
Brigalow within the Brigalow Belt South, Nandewar and Darling Riverine Plains Bioregions      
Byron Bay Dwarf Graminoid Clay Heath Community      
Cooks River/Castlereagh Ironbark Forest in the Sydney Basin Bioregion    
Coolac-Tumut Serpentinite Shrubby Woodland in the NSW South Western Slopes and South Eastern Highlands Bioregions    
Cumberland Plain Woodland in the Sydney Basin Bioregion    
Dry Rainforest of the South East Forests in the South East Corner Bioregion      
Duffys Forest Ecological Community in the Sydney Basin Bioregion      
Eastern Suburbs Banksia Scrub in the Sydney Basin Bioregion  
Elderslie Banksia Scrub Forest      
Fuzzy Box Woodland on alluvial soils of the South Western Slopes, Darling Riverine Plains and Brigalow Belt South Bioregions  
Genowlan Point Allocasuarina nana Heathland      
Gnarled Mossy Cloud Forest on Lord Howe Island    
Grey Box—Grey Gum Wet Sclerophyll Forest in the NSW North Coast Bioregion      
Hunter Floodplain Red Gum Woodland in the NSW North Coast and Sydney Basin Bioregions  
Hunter Valley Weeping Myall Woodland in the Sydney Basin Bioregion  
Hygrocybeae community of Lane Cove Bushland Park in the Sydney Basin Bioregion    
Illawarra Lowlands Grassy Woodland in the Sydney Basin Bioregion  
Illawarra Subtropical Rainforest in the Sydney Basin Bioregion      
Kincumber Scribbly Gum Forest in the Sydney Basin Bioregion      
Lagunaria Swamp Forest on Lord Howe Island  
Low woodland with heathland on indurated sand at Norah Head      
Mallee and Mallee-Broombush dominated woodland and shrubland, lacking Triodia, in the NSW South Western Slopes Bioregion      
Maroota Sands Swamp Forest      
Marsh Club-rush sedgeland in the Darling Riverine Plains Bioregion  
Melaleuca armillaris Tall Shrubland in the Sydney Basin Bioregion  
Milton Ulladulla Subtropical Rainforest in the Sydney Basin Bioregion      
Mount Kaputar high elevation and dry rainforest land snail and slug community in the Nandewar and Brigalow Belt South Bioregions      
Mount Canobolas Xanthoparmelia lichen community      
Monaro Tableland Cool Temperate Grassy Woodland in the South Eastern Highlands Bioregion  √    
New England Peppermint (Eucalyptus nova-anglica) Woodland on Basalts and Sediments in the New England Tableland Bioregion    
Pittwater and Wagstaffe Spotted Gum Forest in the Sydney Basin Bioregion      
Porcupine Grass—Red Mallee—Gum Coolabah hummock grassland/low sparse woodland in the Broken Hill Complex Bioregion      
Quorrobolong Scribbly Gum Woodland in the Sydney Basin Bioregion      
Robertson Basalt Tall Open-forest in the Sydney Basin and South Eastern Highlands Bioregions      
Robertson Rainforest in the Sydney Basin Bioregion      
Shale Sandstone Transition Forest in the Sydney Basin Bioregion    
Snowpatch Feldmark in the Australian Alps Bioregion      
Snowpatch Herbfield in the Australian Alps Bioregion      
Southern Highlands Shale Woodlands in the Sydney Basin Bioregion    
Sun Valley Cabbage Gum Forest in the Sydney Basin Bioregion  
Sydney Turpentine-Ironbark Forest    
Tableland Basalt Forest in the Sydney Basin and South Eastern Highlands Bioregions    
The Shorebird Community occurring on the relict tidal delta sands at Taren Point      
Umina Coastal Sandplain Woodland in the Sydney Basin Bioregion      
Warkworth Sands Woodland in the Sydney Basin Bioregion      
Werriwa Tablelands Cool Temperate Grassy Woodland in the South Eastern Highlands and South East Corner Bioregions  √ √     
Western Sydney Dry Rainforest in the Sydney Basin Bioregion      
White Box Yellow Box Blakely’s Red Gum Woodland    
Windswept Feldmark in the Australian Alps Bioregion      


Species Species Principle
(scientific name) (common name) 1 2 3 4
Acacia acrionastes Pindari wattle      
Acacia atrox Myall Creek wattle    
Acacia bakeri Marblewood      
Acacia carneorum Purple-wood wattle      
Acacia chrysotricha Newry golden wattle      
Acacia constablei Narrabarba wattle    
Acacia courtii North Brother wattle      
Acacia dangarensis        
Acacia jucunda Yetman wattle      
Acacia meiantha        
Acacia pendula population in the Hunter catchment        
Acacia petraea Lancewood      
Acacia phasmoides Phantom wattle      
Acacia pubifolia Velvet wattle      
Acacia rivalis Creek wattle      
Acronychia littoralis Scented Acronychia      
Adelotus brevis Tusked frog population in the Nandewar and New England Tableland bioregions    
Aldrovanda vesiculosa Waterwheel plant      
Alexfloydia repens Floyd's grass      
Allocasuarina glareicola      
Allocasuarina portuensis Nielsen Park she-oak    
Allocasuarina simulans Nabiac casuarina      
Amyema plicatula      
Amytornis barbatus barbatus Grey grasswren      
Amytornis modestus obscurior Thick-billed grasswren (north-west NSW subspecies)      
Amytornis striatus Striated grasswren      
Angiopteris evecta Giant fern    
Angophora exul Gibraltar rock apple    
Anthochaera phrygia Regent honeyeater    
Anthosachne kingiana subsp. Kingiana Philip Island wheat grass    
Aponogeton queenslandicus        
Archidendron hendersonii White lace flower      
Argynnis hyperbius Laced fritillary    
Arthropteris palisotii Lesser creeping fern      
Asterolasia buxifolia        
Asterolasia elegans        
Asterolasia beckersii Dungowan starbush    
Astrotricha cordata Heart-leaved star hair      
Astrotricha crassifolia Thick-leaf star-hair  
Astrotricha sp. Wallagaraugh Merimbula star-hair      
Austrostipa nullanulla A spear-grass      
Baeckea kandos      
Baloghia marmorata Jointed baloghia    
Banksia conferta subsp. conferta Banksia conferta subsp. conferta      
Banksia vincentia Banksia vincentia  
Bertya ingramii Narrow-leaved bertya    
Bertya opponens Coolabah bertya      
Bertya sp. (Chambigne NR, M. Fatemi 24) Chambigne bertya      
Boronia boliviensis Bolivia Hill boronia      
Boronia inflexa subsp. torringtonensis    
Boronia repanda Granite rose      
Boronia ruppii Rupp's boronia    
Bossiaea bombayensis Bombay bossiaea      
Bossiaea fragrans Bossiaea fragrans    
Brachyscome ascendens Border Ranges daisy    
Brachyscome muelleroides Claypan daisy      
Bulbophyllum globuliforme Hoop Pine orchid      
Caesalpinia bonduc Knicker nut      
Caladenia arenaria Sand-hill spider orchid    
Caladenia attenuata Duramana fingers    
Caladenia concolor Crimson spider orchid    
Caladenia tessellata Thick lip spider orchid    
Calidris ferruginea Curlew sandpiper      
Calidris tenuirostris Great knot      
Callistemon megalongensis Megalong Valley bottlebrush      
Callistemon purpurascens      
Callitris baileyi Bailey's cypress pine      
Calochilus pulchellus Pretty beard orchid    
Calomnion complanatum    
Calotis glandulosa Mauve burr-daisy      
Calotis moorei A burr-daisy      
Calyptorhynchus banksii banksii Red-tailed black-cockatoo (coastal subspecies)  
Calystegia affinis    
Camarophyllopsis kearneyi        
Capparis canescens Wild orange  
Caretta caretta Loggerhead turtle      
Carex archeri Archer's carex      
Carex klaphakei Klaphake's sedge      
Cassia marksiana      
Casuarina obesa Swamp she-oak  
Chalinolobus dwyeri Large-eared pied bat      
Cheilanthes sieberi subsp. pseudovellea        
Chiloglottis anaticeps Bird orchid    
Choricarpia subargentea Giant ironwood  
Commersonia rosea        
Convolvulus tedmoorei Bindweed      
Coprosma inopinata Small-leaved currant bush    
Corchorus cunninghamii Native jute      
Corokia whiteana Corokia      
Correa lawrencean avar. genoensis Genoa River correa    
Corunastylis sp. Charmhaven (NSW896673)    
Corynocarpus rupestris subsp. rupestris Glenugie karaka      
Crotalaria cunninghamii Green bird flower      
Cucumis althaeoides      
Cupaniopsis serrata Smooth tuckeroo      
Cyclopsitta diophthalma coxeni Coxen's fig-parrot    
Cyperus rupicola Cliff sedge      
Cyperus semifertilis Missionary nutgrass      
Daphnandra johnsonii Illawarra Socketwood      
Darwinia peduncularis        
Davidsonia johnsonii Smooth davidson's plum    
Dermochelys coriacea Leatherback turtle      
Deyeuxia appressa      
Diospyros mabacea Red-fruited ebony      
Diploglottis campbellii Small-leaved tamarind      
Dipteracanthus australasicus subsp. corynothecus        
Diuris arenaria Sand doubletail      
Diuris bracteata      
Diuris byronensis Byron Bay diuris  
Diuris disposita Willawarrin doubletail    
Diuris flavescens Pale yellow doubletail    
Diuris ochroma Pale golden moths    
Diuris sp. (Oaklands, D.L. Jones 5380) Oaklands diuris      
Dodonaea sinuolata subsp. Acrodentata A hopbush      
Dodonaea stenozyga Desert hopbush    
Dracophyllum macranthum        
Drynaria rigidula Basket fern    
Dysphania plantaginella        
Egernia roomi Kaputar Rock Skink      
Eidothea hardeniana Nightcap oak    
Elaeocarpus williamsianus Hairy quandong  
Elionurus citreus Lemon-scented grass      
Endiandra muelleri subsp. bracteata Green-leaved rose walnut      
Epacris sparsa Sparse heath    
Eriocaulon australasicum Austral pipewort      
Eriocaulon carsonii Salt pipewort    
Erodiophyllum elderi Koonamore daisy      
Erythrotriorchis radiatus Red goshawk    
Esacus magnirostris Beach stone-curlew      
Eucalyptus alligatrix subsp. Alligatrix        
Eucalyptus approximans Barren Mountain mallee      
Eucalyptus aquatica Broad-leaved sally      
Eucalyptus boliviana Bolivia stringybark      
Eucalyptus camphora subsp. Relicta Warra broad-leaved sally      
Eucalyptus canobolensis Silver-Leaf candlebark      
Eucalyptus castrensis Singleton mallee      
Eucalyptus copulans    
Eucalyptus corticosa Creswick apple box      
Eucalyptus dissita Gibraltar mallee      
Eucalyptus fracta Broken back ironbark      
Eucalyptus imlayensis Imlay Mallee  
Eucalyptus kartzoffiana Araluen gum      
Eucalyptus langleyi Albatross mallee      
Eucalyptus microcodon Border mallee    
Eucalyptus oresbia Small-fruited mountain gum      
Eucalyptus pachycalyx subsp. Banyabba Banyabba shiny-barked gum      
Eucalyptus pumila Pokolbin mallee      
Eucalyptus recurva Mongarlowe mallee
Eucalyptus robertsonii subsp. hemisphaerica Robertson's peppermint    
Eucalyptus scoparia Wallangarra white gum      
Eucalyptus sp. Cattai Eucalyptus sp. Cattai      
Eucalyptus sp. Howes Swamp Creek        
Eulamprus leuraensis Blue Mountains water skink      
Euphorbia sarcostemmoides Climbing caustic      
Euphrasia arguta Euphrasia arguta      
Euphrasia bella Pretty eyebright    
Euphrasia bowdeniae        
Euphrasia collina subsp. muelleri Mueller's eyebright    
Euphrasia orthocheila subsp. peraspera Tenterfield eyebright      
Euphrasia scabra Rough eyebright      
Floydia praealta Ball nut    
Fontainea oraria Coastal fontainea    
Galium australe Tangled bedstraw      
Geniostoma huttonii Hutton's geniostoma    
Genoplesium baueri Bauer's midge orchid      
Genoplesium insigne Variable midge orchid    
Genoplesium littorale Tuncurry midge orchid      
Genoplesium plumosum Tallong midge orchid      
Genoplesium rhyoliticum Rhyolite midge orchid      
Genoplesium superbum Superb midge orchid      
Gentiana baeuerlenii Baeuerlen's gentian    
Gentiana bredboensis Bredbo gentian
Gentiana wingecarribiensis Wingecarribee gentian  
Gentiana wissmannii New England gentian    
Geophaps scripta scripta Squatter pigeon (southern subspecies)  
Gingidia rupicola      
Glycine latrobeana        
Goodenia occidentalis Western goodenia      
Grevillea acanthifolia subsp. paludosa Bog grevillea    
Grevillea caleyi Caley's grevillea      
Grevillea divaricata Grevillea divaricata    
Grevillea kennedyana Flame spider flower      
Grevillea hilliana White yiel yiel    
Grevillea iaspicula Wee jasper grevillea      
Grevillea ilicifolia subsp. ilicifolia Holly-leaf grevillea    
Grevillea masonii Mason's grevillea      
Grevillea mollis Soft grevillea      
Grevillea molyneuxii Wingello grevillea      
Grevillea obtusiflora Wingello grevillea      
Grevillea renwickiana Nerriga grevillea      
Grevillea rhizomatosa Gibraltar grevillea      
Grevillea rivularis Carrington Falls grevillea      
Grevillea shiressii        
Grevillea wilkinsonii Tumut grevillea      
Gudeoconcha sophiae magnifica Magnificent helicarionid land snail      
Gyrostemon thesioides      
Hakea pulvinifera Lake Keepit hakea  
Haloragodendron lucasii    
Hibbertia circinata      
Hibbertia fumana        
Hibbertia sp. Bankstown Hibbertia sp. Bankstown    
Hibbertia spanantha Julian's hibbertia    
Hibbertia tenuifolia Narrow-leaved guinea flower  
Homoranthus bebo        
Homoranthus binghiensis Binghi homoranthus      
Homoranthus bruhlii        
Homoranthus croftianus Bolivia homoranthus      
Homoranthus elusus      
Hoplocephalus bungaroides Broad-headed snake      
Hygrocybe anomalavar. ianthinomarginata        
Hygrocybe aurantipes        
Hygrocybe austropratensis        
Hygrocybe collucera        
Hygrocybe griseoramosa        
Hygrocybe lanecovensis        
Hygrocybe reesiae        
Hygrocybe rubronivea        
Indigofera efoliata Leafless indigo    
Indigofera helmsii Indigo      
Indigofera leucotricha Silver indigo      
Indigofera longibractea Showy indigo      
Ipomoea diamantinensis Desert cow-vine      
Ipomoea polymorpha Silky cow-vine    
Irenepharsus magicus Elusive cress    
Isopogon fletcheri Fletcher's drumsticks      
Jalmenus eubulus Pale imperial hairstreak  
Kardomia prominens        
Kardomia silvestris Woodland babingtonia    
Kennedia retrorsa        
Kippistia suaedifolia Fleshy minuria      
Lasiopetalum behrii Pink velvet bush    
Lastreopsis hispida Bristly shield fern    
Lathamus discolor Swift parrot      
Leionema lachnaeoides        
Leionema westonii    
Lenwebbia sp. Main Range    
Lepiderema pulchella Fine-leaved tuckeroo      
Lepidium peregrinum Wandering pepper cress    
Lepidium pseudopapillosum Formbe peppercress      
Lepidorrhachis mooreana Little mountain palm    
Lepidosperma evansianum Evans sedge      
Leptorhynchos waitzia Button immortelle      
Leucopogon confertus Torrington beard-heath      
Lindernia alsinoides Noah's false chickweed      
Lindsaea fraseri Fraser's screw fern      
Litoria castanea Yellow-spotted tree frog
Litoria piperata Peppered tree frog    
Litoria spenceri Spotted tree frog  
Litoria subglandulosa Glandular frog      
Lysimachia vulgaris var. davurica Yellow loosestrife    
Macrozamia humilis Inverell cycad    
Manorina melanotis Black-eared miner  
Melaleuca deanei Deane's paperbark      
Melichrus sp. Gibberagee Narrow-leaf melichrus      
Melicope vitiflora Coast euodia    
Micromyrtus grandis Severn River heath-myrtle      
Micromyrtus minutiflora
Microtis angusii Angus's onion orchid      
Miniopterus australis Little bent-winged bat      
Miniopterus orianae oceanensis Large bent-winged bat      
Mitrasacme pygmaea Pygmy bishop's Hat    
Mixophyes balbus Stuttering frog      
Mixophyes fleayi Fleay's barred frog      
Monotoca rotundifolia Trailing monotoca      
Muellerina myrtifolia Myrtle-leaf mistletoe      
Myriophyllum implicatum Myriophyllum implicatum    
Myrsine richmondensis Ripple-leaf muttonwood    
Mystivagor mastersi Masters charopid land snail      
Myuchelys georgesi Bellinger River snapping turtle    
Nematolepis rhytidophylla Nalbaugh nematolepis    
Neoastelia spectabilis Silver sword lily      
Neophema chrysogaster Orange-bellied parrot    
Niemeyera chartacea Smooth-leaved plum      
Nitella parooensis        
Nitella partita        
Numenius madagascariensis Eastern curlew      
Oberonia complanata Yellow-flowered king of the fairies    
Ochrosia moorei Southern ochrosia    
Oldenlandia galioides      
Olearia flocktoniae Dorrigo daisy bush      
Osteocarpum scleropterum Squash bush      
Owenia cepiodora Onion cedar      
Pachycephala rufogularis Red-lored whistler      
Pedionomus torquatus Plains-wanderer      
Pelargonium sp. Striatellum Omeo storksbill      
Peristeranthus hillii Brown Fairy-chain orchid      
Persoonia hindii        
Persoonia hirsuta Hairy geebung      
Persoonia pauciflora North Rothbury persoonia    
Petalura gigantea Giant dragonfly      
Petalura litorea Coastal petaltail      
Petrogale penicillata Brush-tailed rock-wallaby      
Petrogale xanthopus Yellow-footed rock-wallaby    
Phebalium bifidum      
Phebalium glandulosum subsp. Eglandulosum Rusty desert phebalium      
Phebalium speciosum        
Pherosphaera fitzgeraldii Dwarf mountain pine      
Pilularia novae-hollandiae Austral pillwort      
Pimelea axiflora subsp. Pubescens Bungonia rice-flower    
Pimelea bracteata        
Pimelea cremnophila      
Pimelea serpyllifolia subsp. serpyllifolia Thyme rice-flower      
Pimelea venosa Bolivia Hill pimelea    
Platyzoma microphyllum Braid fern      
Plectranthus alloplectus Narrow-leaved plectranthus    
Plinthanthesis rodwayi Budawangs wallaby grass    
Polycarpaea spirostylis subsp. glabra        
Polystichum moorei Rock shield fern    
Pomaderris adnata Sublime point pomaderris      
Pomaderris cocoparrana        
Pomaderris delicata Delicate pomaderris      
Pomaderris gilmourii var. cana Grey deua pomaderris    
Pomaderris pallida Pale pomaderris      
Pomaderris reperta Denman pomaderris      
Pomaderris sericea Silky pomaderris      
Pomaderris walshii Carrington Falls pomaderris    
Potorous longipes Long-footed potoroo      
Prasophyllum affine Jervis Bay leek orchid      
Prasophyllum bagoense Prasophyllum bagoense      
Prasophyllum canaliculatum Summer leek orchid    
Prasophyllum fuscum Slaty leek orchid    
Prasophyllum innubum Prasophyllum innubum      
Prasophyllum keltonii Kelton's leek orchid      
Prasophyllum sp. Majors Creek Majors Creek leek orchid
Prasophyllum sp. Moama Prasophyllum sp. Moama      
Prasophyllum sp. Wybong        
Prostanthera discolor      
Prostanthera gilesii    
Prostanthera marifolia Seaforth mintbush    
Prostanthera palustris Swamp mint-bush      
Prostanthera sejuncta      
Prostanthera staurophylla sensu stricto      
Pseudanthus ovalifolius Oval-leafed pseudanthus      
Pseudocharopa ledgbirdi Mount Lidgbird charopid land snail      
Pseudocharopa whiteleggei Whitelegge's land snail      
Pseudomys desertor Desert mouse    
Pseudomys fumeus Smoky mouse    
Pseudophryne corroboree Southern corroboree frog
Pseudophryne pengilleyi Northern corroboree frog      
Psilotum complanatum Flat fork fern    
Pterostylis bicornis Horned greenhood    
Pterostylis despectans Pterostylis despectans    
Pterostylis metcalfei Metcalfe's greenhood      
Pterostylis nigricans Dark greenhood      
Pterostylis oreophila Blue-tongued greenhood    
Pterostylis pulchella Waterfall greenhood      
Pterostylis riparia        
Pterostylis sp. Botany Bay Botany Bay bearded orchid    
Pterostylis ventricosa Pterostylis ventricosa      
Pterostylis vernalis Pterostylis vernalis      
Pultenaea elusa Elusive bush-pea  
Pultenaea parrisiae Parris' bush-pea    
Pultenaea sp. Genowlan Point Pultenaea sp. Genowlan point  
Randia moorei Spiny gardenia      
Rhizanthella slateri Eastern australian underground orchid      
Rhodamnia rubescens Scrub turpentine      
Rhodomyrtus psidioides Native guava      
Rotala tripartita        
Rytidosperma pumilum Feldmark grass      
Rytidosperma vickeryae Perisher wallaby-grass      
Sarcochilus dilatatus Brown butterfly orchid      
Sarcochilus weinthalii Blotched sarcochilus      
Scaevola collaris Fan flower      
Senecio linearifolius var. dangarensis        
Senecio squarrosus Swamp groundsel    
Solanum armourense
Solanum limitare Border Ranges nightshade  
Solanum sulphureum Manning yellow solanum      
Stackhousia clementii        
Styphelia perileuca Montane green five-corners      
Swainsona adenophylla Violet swainson-pea      
Swainsona flavicarinata Yellow-keeled swainsona      
Swainsona viridis Creeping Darling pea      
Synemon plana Golden sun moth      
Syzygium moorei Durobby      
Tasmannia glaucifolia Fragrant pepperbush      
Thelymitra adorata Wyong sun orchid    
Thelymitra atronitida Black-hooded sun orchid    
Thelymitra kangaloonica Kangaloon sun orchid    
Thersites mitchellae Mitchell's rainforest snail    
Thinornis cucullatus cucullatus Eastern Hooded Dotterel      
Threlkeldia inchoata Tall bonefruit      
Triflorensia cameronii Cameron's tarenna    
Triplarina imbricata Creek triplarina      
Turnix melanogaster Black-breasted button-quail      
Typhonium sp. aff. brownii Stinky lily    
Tyto tenebricosa Sooty owl      
Vespadelus troughtoni Eastern cave bat      
Wollemia nobilis Wollemi pine    
Xanthosia scopulicola      
Xerothamnella parvifolia      
Xylosma parvifolia Mountain xylosma    
Xylosma terrae-reginae Queensland xylosma      
Zieria adenodonta Wollumbin zieria      
Zieria adenophora Araluen zieria    
Zieria baeuerlenii Bomaderry zieria      
Zieria buxijugum Box range zieria  
Zieria citriodora Lemon zieria      
Zieria covenyi Coveny's zieria    
Zieria floydii Floyd's zieria      
Zieria formosa Shapely zieria    
Zieria lasiocaulis Willi Willi zieria      
Zieria obcordata        
Zieria odorifera subsp. copelandii      
Zieria odorifera subsp. warrabahensis      
Zieria parrisiae Parris' zieria    
Zieria tuberculata Warty zieria      

Principles for determining serious and irreversible impacts

An impact is to be regarded as serious and irreversible if it is likely to contribute significantly to the risk of a threatened species or ecological community becoming extinct because:

  • it will cause a further decline of a species or ecological community that is currently observed, estimated, inferred or reasonably suspected to be in a rapid rate of decline
  • it will further reduce the population size of the species or ecological community that is currently observed, estimated, inferred or reasonably suspected to have a very small population size
  • it is an impact on the habitat of the species or ecological community that is currently observed, estimated, inferred or reasonably suspected to have a very limited geographic distribution
  • the impacted species or ecological community is unlikely to respond to measures to improve its habitat and vegetation integrity and therefore its members are not replaceable.

These principles are set out in clause 6.7 of the Biodiversity Conservation Regulation 2017.

Thresholds for serious and irreversible impacts

The guidance indicates that each entity at risk of a serious and irreversible impact (SAII) will have an impact threshold identified. Please note that the requirement to identify impact thresholds only applies under the BAM 2017. Thresholds for SAII are not included in the assessment requirements under the new BAM 2020, which came into force on 22 October 2020.

Transitional arrangements allow an accredited person to prepare a Biodiversity Assessment Report (BAR) based on the BAM 2017. When reviewing a BAR based on the BAM 2017, the impact thresholds will be one factor that the approval authority will consider, alongside other information provided in the BAR, to determine whether a serious and irreversible impact is likely to occur.

Impact thresholds for some entities at risk of a SAII are available in the Threatened Biodiversity Data Collection hosted by BioNet. For other entities, thresholds have not been developed. For example, thresholds have not been assigned to any threatened ecological communities. In the absence of thresholds, the consent authority can disregard references to considering thresholds in the guidance when making their determination.

For BAM 2020, the impact assessment criteria for entities at risk of serious and irreversible impacts now align with the Principles defined in the Biodiversity Conservation Regulation 2017. Assessors are required to address these criteria. This information will aid the decision-maker in forming an opinion on whether the impact will be serious and irreversible.