Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 161
SITE REL11 PROJ Greater Paraburdoo Targeted Riparian/GDE study DATE 17-Jul-18 SEAS_COND Good SITE_TYPE Relevé SITE_DIM ~25 x 100 E_PHOTO 168-171 HABITAT Major drainage; slightly elevated (compared to main channel) side channel with depressions. SOIL Dark reddish brown clay loam. ROCK_TYPE Riverstone, ironstone gravel, pebbles and cobbles.
VEGETATION Eucalyptus camaldulensis subsp. refulgens woodland over Acacia citrinoviridis, A. ampliceps tall shrubland over Cyperus vaginatus open sedgeland over Pluchea rubelliflora low open shrubland over *Cenchrus ciliaris very open tussock grassland.
VEG_COND Very Good; low density of weeds, and low cattle activity. FIRE_AGE Very Long Unburnt. NOTES PROJ 1361_GDE SITE REL11 POSITION C DATUM WGS84 ZONE 50 EAST 576618 NORTH 7419811 EAST_GDA 576618 NORTH_GDA 7419811 LATITUDE_GDA -23.32937 LONGITUDE_GDA 117.749443
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 163
SITE REL12 PROJ Greater Paraburdoo Targeted Riparian/GDE study DATE 17-Jul-18 SEAS_COND Good SITE_TYPE Relevé SITE_DIM ~25 x 100 E_PHOTO 189-190 HABITAT Major drainage; low side channel (parallel), bed and narrow islands. SOIL Dark reddish brown sandy clay loam (bed); clay loam bank. ROCK_TYPE Riverstone’s, ironstones and calcrete platform.
VEGETATION
Eucalyptus camaldulensis subsp. refulgens (E. victrix) open forest over Melaleuca glomerata (Acacia ampliceps, A. citrinoviridis) tall open shrubland over Cyperus vaginatus scattered sedges over Samolus sp. Millstream (M.I.H. Brooker 2076), Pluchea rubelliflora low open shrubland over *Cenchrus ciliaris very open tussock grassland.
VEG_COND Very Good; low density weeds, and some cattle disturbance. FIRE_AGE Very Long Unburnt. NOTES PROJ 1361_GDE SITE REL12 POSITION C DATUM WGS84 ZONE 50 EAST 583076 NORTH 7415864 EAST_GDA 583076 NORTH_GDA 7415864 LATITUDE_GDA -23.364704 LONGITUDE_GDA 117.812825
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 165
SITE REL13 PROJ Greater Paraburdoo Targeted Riparian/GDE study DATE 18-Jul-18 SEAS_COND Good SITE_TYPE Relevé SITE_DIM E_PHOTO 8409-8410 HABITAT Major drainage; bed with minor channels of Ma, rocky sandy bed, and low minor almost dry pools with sedges. SOIL Dark reddish brown clay loam (bed), clay loam on narrow islands. ROCK_TYPE Riverstone, ironstone.
VEGETATION Melaleuca argentea (Eucalyptus camaldulensis subsp. refulgens) open forest over Acacia ampliceps tall open shrubland over Samolus sp. Millstream (M.I.H. Brooker 2076) scattered low shrubs with Cyperus vaginatus very open sedgeland.
VEG_COND Very Good; low density of *Cenchrus ciliaris, and minimal cattle disturbance. FIRE_AGE Very Long Unburnt. NOTES Dry shallow pools with dying Schoenoplectus subulatus. PROJ 1361_GDE SITE REL13 POSITION C DATUM WGS84 ZONE 50 EAST 584270 NORTH 7415303 EAST_GDA 584270 NORTH_GDA 7415303 LATITUDE_GDA -23.36971 LONGITUDE_GDA 117.824538
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 167
Appendix I: Sensitivity and significance attribution data. Ve
g ID
Veg
code
Repl
icat
e
location Sensitivity Initial Significance Final Significance
Final Significance
Number Notes
1 C1-A 1 TUREE Creek Very High Very High (To High (+)) Very High 10
OPV - SIGNIFICANT - Young to Mature M. argentea
1 C1-A 2 TUREE Creek Very High Very High (To High (+)) Very High 10
OPV - SIGNIFICANT- Semi-Mature to Mature M. argentea
3 C1-Bb 1 TUREE Creek Very High High (+) High 9 OPV - Young to Mature M. argentea
8 C2-AA-R 1 Seven Mile/Pirraburdu Creek High High High 9 Apparently ‘wettest’ vegetation within Pirraburdu Creek
2 C1-Ba 1 TUREE Creek High High High 8 Obligate Phreatophytic Vegetation (OPV) 4 C1-C 1 TUREE Creek High High High 8 Obligate Phreatophytic Vegetation (OPV) 6 C2-AA 1 Seven Mile /Pirraburdu Creek High High High 8 High (+) (to V high) Historical Persistence 5 C2-A 1 DOGGERS Gorge High Moderate (+) High 8 DOGGERS Gorge 5 C2-A 2 Seven Mile /Pirraburdu Creek High Moderate-High High 8 High Historical Persistence 5 C2-A 3 Seven Mile /Pirraburdu Creek High Moderate-High High 8 High (+) Historical Persistence
33 P 1 TUREE Creek High High (+) High 8 34 P 2 TUREE Creek High High (+) High 8 35 P-M 1 GREATER PARABURDOO High Moderate-High Moderate 8 ARTIFICIAL/MODIFIED POOL 6 C2-AA 2 Seven Mile /Pirraburdu Creek High High Moderate-High-P 7.1 High (to High +) Historical Persistence 5 C2-A 4 Seven Mile /Pirraburdu Creek High Moderate-High Moderate-High-P 7.1 High (+) (to V high) Historical Persistence 6 C2-AA 3 Seven Mile /Pirraburdu Creek High High Moderate-High 7 High (-) Historical Persistence
9 C2-A-T 1 TUREE Creek Moderate to High Moderate-High Moderate-High 7
10 C2-B 1 Seven Mile /Pirraburdu Creek Moderate to High Moderate (+) Moderate-High 7 High (-) Historical Persistence
12 C2-B-S 1 TUREE- NEERAMBAH SP High High Moderate-High 7 NEERAMBAH Spring - SIGNIFICANT
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 168
Veg
ID
Veg
code
Repl
icat
e location Sensitivity Initial Significance Final Significance
Final Significance
Number Notes
15 C2-C-MG 1 DOGGERS Gorge Moderate to High Moderate (+) Moderate-High 7
DOGGERS Gorge - M. glomerata abundant
7 C2-AA-H 1 Seven Mile /Pirraburdu Creek High Moderate-High Moderate 6 HEAVILY MODIFIED 13 C2-C 1 TUREE Creek Moderate Moderate (+) Moderate 6
15 C2-C-MG 2 Seven Mile /Pirraburdu Creek Moderate to High Moderate (+) Moderate 6 M. glomerata abundant
15 C2-C-MG 3 DOGGERS Gorge Moderate to High Moderate Moderate 6
28 D8-C-MG 2 DOGGERS - GREATER PARA Low Minor-Moderate Minor-Moderate 4 DOGGERS Gorge - M. glomerata abundant
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 170
Veg
ID
Veg
code
Repl
icat
e location Sensitivity Initial Significance Final Significance
Final Significance
Number Notes 13 C2-C 5 Seven Mile /Pirraburdu Creek Moderate Minor-Moderate Minor 3 13 C2-C 6 Seven Mile /Pirraburdu Creek Moderate Minor-Moderate Minor 3 14 C2-C-H 1 Seven Mile /Pirraburdu Creek Moderate Minor-Moderate Minor 3 HEAVILY MODIFIED 20 D7-B 9 Seven Mile /Pirraburdu Creek Moderate Minor-Moderate Minor 3 23 D7-C 3 GREATER PARABURDOO Moderate Minor (+) Minor 3 23 D7-C 4 TUREE Creek Moderate Minor (+) Minor 3
25 D8-B 3 GREATER PARABURDOO Moderate to Low Minor-Moderate Minor 3 ORIGINAL ASTRON UNIT (D7)
25 D8-B 4 GREATER PARABURDOO Moderate to Low Minor-Moderate Minor 3
27 D8-C 2 TUREE - NEERAMBAH SP Low Minor (+) Minor 3 NEERAMBAH Spring 27 D8-C 3 TUREE Creek Low Minor-Moderate Minor 3 27 D8-C 4 GREATER PARABURDOO Low Minor (+) Minor 3 29 D8-D 1 TUREE Creek Low Minor (+) Minor 3 31 D8-D-S 1 TUREE - NEERAMBAH SP Low Minor Minor 3 NEERAMBAH - Spring SHRUBLAND 17 D14 1 GREATER PARABURDOO Very Low Minor Minor 2 29 D8-D 2 GREATER PARABURDOO Low Minor Minor 2 29 D8-D 3 GREATER PARABURDOO Low Minor Minor 2 32 D9 1 TUREE Creek Very Low Minor Minor 2 Shrubland 32 D9 2 GREATER PARABURDOO Very Low Minor Minor 2 ORIGINAL ASTRON UNIT (D9) 30 D8-D-H 1 GREATER PARABURDOO Low Minor Low 1 HEAVILY MODIFIED
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 171
Appendix J: Risk mapping; Ratings and location for risk attributed to different areas (zones) within the GPO generated as part of the risk mapping process
(Orange Shading indicates risk zones dealt with in further detail as part of impact assessments conducted for 4EE dewatering within Seven Mile Creek – i.e. those areas of significant risk which can be broadly attributed to this? current proposal).
Zone Code Risk Rating Risk
Rating # Location Risk Notes - Source(s) of risk and context
Risk Source: Current operations / New Proposal
1A Very High 7 Seven Mile Creek North
Dewatering zone (direct) - 4EE Dewatering (Brockman/Wittenoom formation)
Low (Drought-dewatering Dependent) 3.1 Pirraburdu Creek
Indirect 4E dewatering, Brockman/Wittenoom formation(& Fortescue aquifer)
Broadly attributed to Current/historical operations with some low potential for change from new proposal
8C
Low (Drought-Borefield Dependent) 3.1 Turee Creek
Turee/Channar Borefield in combination with drought
Broadly attributed Current/historical operations.
7 Low (Drought Dependent) 3.1
Doggers Gorge/Geode Creek
Channar dewatering in combination with drought
Broadly attributed Current/historical operations.
5 Low 3 Western Range - Six Mile Creek
Dewatering of Western Range Pit, in combination with drought.
Attributed to New Proposal
4C Low (Town Supply) 3
Seven Mile Creek North
Paraburdoo Northern Borefield (Indirect) in combination with drought.
Broadly attributed Current/historical operations.
3B Low 3 Seven Mile Creek South
Indirect (alluvial Aquifer) - 4EE Dewatering (Brockman/Wittenoom formation), and drawdown within the Weeli Wolli Formation (Hamersley group) and Mount McGrath Member (Wyloo Group).
Broadly attributed to Current/historical operations with some low potential for change from new proposal (particularly from changed discharge location)
A combination of old operations with low levels of potential change
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 173
Zone Code Risk Rating Risk
Rating # Location Risk Notes - Source(s) of risk and context
Risk Source: Current operations / New Proposal from new proposal (and discharge relocation)
GPO-A Very Low 2 Greater Paraburdoo
Widespread zone - Multiple potential influences and sources
Broadly attributed Current/historical operations, with some potential in certain areas for very low levels of change as a result of the new proposal.
8D Very Low 2 Channar Discharge Augmentation based Risk (following cessation of discharge)
Broadly attributed Current/historical operations.
GPO-B Minimal 1 Greater Paraburdoo
Widespread zone - Multiple potential influences and sources
Broadly attributed Current/historical operations.
GPO-C Negligible 0 Greater Paraburdoo
Widespread zone - Multiple potential influences and sources
Broadly attributed Current/historical operations.
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 174
Appendix K: Riparian features identified by the contextual assessment of the distribution of 'Mesic' Riparian Formations (and known/potential GDE’s) within a 100 km Radius of the Paraurdoo operations
Feature ID
Feature Name or Study Derived Name Broad Location Drainage System
Located In Study Area/
National Park
Size Class of System
Notes - Where applicable
MGA Zone 50 (GDA 94) (centrepoint)
Easting Northing
19 Upper Turee Creek - Billingarra Springs
Southern Central Hamersley Ranges Turee Creek Main KNP Large Medium to large 613259.9 7426606
20 Upper Turee Creek West - Syncline Pools
Southern Central Hamersley Ranges Turee Creek West KNP Large
Riparian formations & Pools 610182.8 7440564
21 Upper Turee Creek west - Pools
Central Hamersley Ranges Turee Creek West KNP Large
Riparian formations & Pools 617205 7461535
58 Turee Creek - Pools - Neerambah Corner
Southern Central Hamersley Ranges Turee Creek Main Study Area 1 Large large - SIGNIFICANT 574808.3 7419625
59 Turee Creek - Nanjilgardy Pool area
Southern Central Hamersley Ranges Turee Creek Main Study Area Large large - SIGNIFICANT 583819.5 7415639
60 Turee Creek - Windell/ Kalkamunda Pool areas
Southern Central Hamersley Ranges Turee Creek Main Study Area Large large - SIGNIFICANT 598820.3 7414964
2 Hardy River - Central Pools Southern Central Hamersley Ranges Hardy River Large ? Significant 520693.8 7459118
13 Hardy River - Upper pools Southern Central Hamersley Ranges Hardy River Large ? Significant 539633.9 7462501
63 Turee Creek east Branch - Kooinana Pool
Southern Central Hamersley Ranges Turee Creek East Large ? Significant 630582.2 7424487
67 Angelo River - Extensive Riparian formations
Southern Central Hamersley Ranges Angelo River Large
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 179
Appendix L: Table presenting the hydrological Impact assessment and predicted outcomes for vegetation by risk zone within the key impact zone of Seven Mile Creek.
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 180
Zone
Risk
Rating
Base
line
Dept
h to
Wat
er (r
ange
)
Description of Vegetation structure/composition/modi
fication in relation to Baseline conditions Hy
drol
ogic
al
influ
ence
zone
Likely hydrological impacts Relevant to impacting or sustaining riparian vegetation
Relevant Vegetation Stressors
(and predicted magnitude of influence). Potential Impact to present day Riparian Vegetation
Indication of the role the alluvial aquifer might play in this Biotic/hydrologic
interaction (see Section 3.5 for Biotic/hydrologic Interaction notes)
Key changes likely to come from the interaction between all listed stressors, with the interaction likely peaking late in the dry season (early wet season).
1A
Very
Hig
h (7
)
1-6 m
Present day vegetation likely has a similar structure/composition (previously Open forest/Mesic) to Baseline vegetation (pre-mining - Pre 1970's) but now displaying discharge augmentation (moderate degree) which together with disturbance (moderate to high; including ponding related disturbance) has led to a moderate degree of modification in vegetation from its baseline state.
Ove
rlyin
g Di
rect
Dew
ater
ing
influ
ence
zone
(m
inin
g)
Groundwater in the underlying lithology likely perennially dry or punctuated by 1-2 month periods where it is rehydrated by surface flows. The SMC alluvial aquifer will generally be out of reach of riparian vegetation, however seasonal surface water flows will provide temporary recharge and some potential mitiagtive influence (minimal). Surface water recharge in the alluvials will likely have minimal residence time in the order of 1-3 months (1+ months for phreatic water, 2-3 months for the bulk of vadose water), thus the alluvial aquifer is likely to be broadly dry outside surface flow periods. Discharge may* supplement.
(1) Lithological drawdown (High), (2) Alluvial drawdown (High), (3) Baseline Root clipping (High), (4) Vegetation augmentation (low to moderate), (5) 'Mesic' understorey constituents (High to Moderate), (6) Decreased residence time of surface water recharge events (High), (7) removal of surplus water discharge (Low). . SMC alluvial aquifer unlikely to provide a sustaining influence to vegetation outside the surface flow recharge events of the wet season.
Vegetation is likely to transition from a 'Mesic' to an 'ephemeral' state. Through severe canopy decline, and cavitation related mortality; this process has the potential to reduce 'vegetation cover' (i.e. vegetation density) of the Upper and Mid-strata (within the established vegetation association) by up to two structural formation classes** (e.g. Open Forest reduced to Woodland or Open Woodland). However cover changes equivalent to one structural formation class change in both overstorey and understorey are most likely, with increasing potential for change by two classes in the understorey. This cover change is likely to be accompanied by compositional changes within associated**** and dominant**** taxa. These changes are most likely represented by the removal of Sesbania formosa, Acacia ampliceps and Melaleuca bracteata within the Mid-storey.
2A
Hig
h (6
)
2-7 m
Present day vegetation likely has a similar structure/composition (previously Open Forest/'Mesic') to Baseline vegetation state but now displaying significant discharge augmentation (particularly at the north eastern end of the zone)(now; Forest to Open Forest/'Mesic' conditions) which together with disturbance has led to a moderate degree (Moderate to high in the eastern portions) of modification in vegetation from its baseline state.
Indi
rect
influ
ence
Zon
e (m
inin
g) -
SMC
allu
vial
aqu
ifer
Groundwater in the underlying lithology likely to remain unchanged by the proposal. Within the dry season, drawdown within the SMC alluvial aquifer, where it overlies the Wittenoom formation, is likely to propagate upstream and throughout Zone 2A, particularly late in the dry season. The ability (and magnitude) of this to occur depends on the degree of hydraulic connectivity between the Wittenoom formation, the clayey weathered bedrock basement, deeper alluvial layers and the SMC alluvial aquifer. Another important factor is the amount of throughflow within the alluvial aquifer (i.e. inputs) coming from upstream of this zone. This throughflow input is most likely to be lowest at the time of year when alluvials are at their driest (late dry-season/early wet-season), and thus when upstream propagtion of drawdown is likely to be at its highest. This may result in the SMC alluvial aquifer being seasonally inaccessible (at least partially). Surface water recharge events within the alluvials will likely have minimal to moderate residence time in the order of 2-6 months (1+ months for phreatic water, 2-6 months for the bulk of vadose water). Discharge may* supplement.
(2) Alluvial drawdown (High to moderate), (3) Baseline Root clipping (High to Moderate), (4) Vegetation augmentation (Moderate), (5) 'Mesic' understorey constituents (high), (6) Decreased residence time of surface water recharge events (Moderate to Low). (7) removal of surplus water discharge (Moderate). . SMC alluvial aquifer likely providing low to negligible sustaining influence to vegetation outside the surface flow recharge events of the wet season.
Vegetation is likely to transition from a 'mesic' to 'Semi Mesic' (and in places 'ephemeral'; i.e. downstream end) state. Through severe canopy decline, and cavitation related mortality; this process has the potential to reduce 'vegetation cover' of the Upper and Mid-strata (within the established vegetation association) by at least one structural formation class**. However while there is potential for one class change in the whole zone (particularly in the understorey); equivalent and potentially greater cover changes are most likely in the downstream extents of the zone (e.g. Open Forest to Woodland). This cover change is likely to be accompanied by compositional changes within 'associated' vegetation taxa. Changes within dominant taxa**** is is also possible, particularly in the understorey. These changes are most likely represented by the removal of Sesbania formosa, Acacia ampliceps, and less so Melaleuca bracteata. Removal of discharge* likely to play a key role in these changes to structure and composition.
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 181
Zone
Risk
Rating
Base
line
Dept
h to
Wat
er (r
ange
)
Description of Vegetation structure/composition/modi
fication in relation to Baseline conditions Hy
drol
ogic
al
influ
ence
zone
Likely hydrological impacts Relevant to impacting or sustaining riparian vegetation
Relevant Vegetation Stressors
(and predicted magnitude of influence). Potential Impact to present day Riparian Vegetation
Indication of the role the alluvial aquifer might play in this Biotic/hydrologic
interaction (see Section 3.5 for Biotic/hydrologic Interaction notes)
Key changes likely to come from the interaction between all listed stressors, with the interaction likely peaking late in the dry season (early wet season).
2B
Mod
erat
e (5
)
2-8 m
Present day vegetation has likely experienced a moderate degree of change in both structure and composition (Woodland converted to Open Forest/'Semi-mesic' converted to 'mesic') from the baseline state via discharge augmentation (moderate to low degree) and disturbance (moderate).
Indi
rect
influ
ence
Zon
e (m
inin
g) -
SMC
allu
vial
aq
uife
r
Groundwater in the underlying lithology unlikely to be influenced by the adjacent dewatered Wittenoom formation (may be in parts). Dry season propagation of dewatering within the alluvial aquifer in the adjacent zone (2A) is likely to propagate (to a low degree) upstream and through at least parts of this Zone. Seven Mile alluvial aquifer likely providing insufficient (low to moderate) sustaining influence to vegetation outside the recharge events of the wet season. Uncertainty surrounding basement morphology and its influence on the propagation of change within the seven mile aquifer upstream of its interface with the Wittenoom formation may be an important determining factor to this process. Discharge may* supplement. If discharge removed; propagation potential will increase.
(2) Alluvial drawdown (moderate to low), (3) Baseline Root clipping (Moderate to High (west end)), (4) Vegetation augmentation (Moderate to high (west end)), (5) 'Mesic' understorey constituents (moderate to high), (7) removal of surplus water discharge (Low to Moderate). . SMC alluvial aquifer likely providing insufficient (low to moderate) sustaining influence to vegetation outside the recharge events of the surface flow season.
Vegetation is likely to transition from 'mesic'/'semi-mesic' to a 'semi-mesic'/'ephemeral' state (Semi-Mesic at downstream end). Through severe canopy decline, and cavitation related mortality; this process has the potential to reduce 'vegetation cover' of the Upper and Mid-strata (within the established vegetation association) by one structural formation class**, particularly in the downstream half of this zone (eg. Open Forest to Woodland). However cover changes equivalent to less than (but approaching) one structural formation class change in both overstorey and understorey, are most likely (particularly in the understorey at the downstream end). This cover change is likely to be accompanied by compositional changes within 'associated'**** vegetation taxa. There is a low potential for changes within dominant**** taxa to occur, mainly in the wetter downstream extents, particularly in the understorey. These changes are most likely represented by the removal of Sesbania formosa, and less so Acacia ampliceps. Removal of discharge* likely to play a substantial role in these changes to structure and composition due to the potential role of discharge in the maintenance of a shallow SMC aquifer in this vicinity.
1B
Mod
erat
e to
Low
(4)
8-15 m
Present day vegetation likely has a similar structure/composition (Open woodland to Scattered Trees/'Ephemeral') to the baseline vegetation state, but there is potential for some level of augmentation (minor degree) and modification to have occurred. Physical disturbance through this zone is high, and so overall modification is considered high.
Ove
rlyin
g Di
rect
Dew
ater
ing
influ
ence
zone
(m
inin
g)
Groundwater in the underlying lithology likely perennially dry or punctuated by 1-2 month periods where it is rehydrated by surface flows. Outside periods where surface flows lift the SMC alluvial aquifer to a point where it is accessible to riparian vegetation, the SMC alluvial aquifer will generally be inaccessible to riparian vegetation. Seasonal surface water flows will provide temporary recharge and some potential mitiagtive influence (minimal). Surface water recharge in the alluvials will likely have minimal residence time in the order of 1-4 months (1+ months for phreatic water, 2-4 months for the bulk of vadose water), thus the alluvial aquifer is likely to be broadly dry outside surface flow periods. Discharge may* supplement.
(1) Lithological drawdown (High), (2) Alluvial drawdown (High), (5) 'Mesic' understorey constituents (Low), (6) Decreased residence time of surface water recharge events (High). . Outside the surface flow recharge events of the wet season, vegetation will not be able to access the SMC alluvial aquifer.
It’s unclear whether vegetation in this zone has noticbly changed from its baseline state. Available information suggests that if vegetation change as a result of groundwater abstraction has occurred, it is most likely to be relatively low in magnitude. Vegetation may be impacted (or further impacted) following the proposed hydrological change, but how much is unclear. New and significant changes to groundwater access by vegetation are unlikely in this zone. As a result; the relatively low degrees of baseline riparian 'vegetation cover' within this zone determines that vegetation structural formation changes in this zone are unlikely but possible. However; there is potential for the overstorey dominance of Eucalyptus camaldulensis to be reduced in this zone. This would likely manifest in a 10-30% 'canopy cover' reduction and increased overstorey mortality of up to 10% of the population. Furthermore; some degree of compositional change within associated**** taxa could potentially occur (most likely among more 'mesic' Mid and Ground strata components).
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 182
Zone
Risk
Rating
Base
line
Dept
h to
Wat
er (r
ange
)
Description of Vegetation structure/composition/modi
fication in relation to Baseline conditions Hy
drol
ogic
al
influ
ence
zone
Likely hydrological impacts Relevant to impacting or sustaining riparian vegetation
Relevant Vegetation Stressors
(and predicted magnitude of influence). Potential Impact to present day Riparian Vegetation
Indication of the role the alluvial aquifer might play in this Biotic/hydrologic
interaction (see Section 3.5 for Biotic/hydrologic Interaction notes)
Key changes likely to come from the interaction between all listed stressors, with the interaction likely peaking late in the dry season (early wet season).
2C
Mod
erat
e to
Low
(4)
4-8 m
Present day vegetation (both structure and composition) is likely similar to that at baseline, with some areas having received a low degree of augmentation. In augmented areas Structure/composition has likely changed from Open woodland/Woodland to Woodland more broadly, with composition slightly more mesic than the baseline state. Changes broadly a result of discharge augmentation and associated mounding in the alluvial aquifer.
Indi
rect
influ
ence
Zon
e (m
inin
g) -
Seve
n M
ile C
reek
allu
vial
aqu
ifer
Groundwater in the underlying lithology highly unlikely to be influenced by the downstream dewatered wittenoom formation. Dry season propagation of dewatering within the alluvial aquifer in the adjacent zone (2B) has the potential to propagate (to a low degree) upstream and through at least parts of this Zone in the late Dry season. Uncertainty surrounding basement morphology (and associated bathtubs) and its influence on the propagation of drawdown upstream within the SMC alluvial aquifer may be an important determining factor to this process. The upstream limit of this zone at Kelly's pool is attributed to evidence for either a basement (bathtub)) or structural barrier (dyke) to upstream propagation. Discharge unlikely to significantly supplement aquifer in this zone, but may indirectly influence this area. Discharge* removal therefore may influence vegetation.
(2) Alluvial drawdown (low), (3) Baseline Root clipping (Moderate to low), (4) Vegetation augmentation (low), (5) 'Mesic' understorey constituents (moderate to low). (7) removal of surplus water discharge (Very Low). . Seven Mile alluvial aquifer may produce reduced sustaining influence to vegetation outside the surface flow recharge events of the wet season.
There is potential for the vegetation of this zone to transition from a 'Semi Mesic' to a more 'ephemeral' state. Through extended canopy decline, and cavitation related mortality; this process has the potential to reduce vegetation cover in both the Upper and Mid-strata (within the established vegetation association) by less than (or equal to) one structural formation class**. However cover changes equivalent to (but approaching) one structural formation class change are unlikely in the overstorey and possible in the understorey. Reductions in 'Canopy Cover' in the order of 10-20% are like to acompany potential vegetation cover changes in this zone; mostly in the south western half of this zone, particularly if discharge is ceased. In the north eastern half, reduced potential for drawdown propagation also means reduced potential for impact to vegetation. There is some potential for compositional changes (associated**** species only) within more 'mesic' vegetation types of this zone. In the western half of this zone, vegetation cover changes may result from the removal of discharge given its potential role in the maintenance of a shallow SMC aquifer in this vicinity.
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 183
Zone
Risk
Rating
Base
line
Dept
h to
Wat
er (r
ange
)
Description of Vegetation structure/composition/modi
fication in relation to Baseline conditions Hy
drol
ogic
al
influ
ence
zone
Likely hydrological impacts Relevant to impacting or sustaining riparian vegetation
Relevant Vegetation Stressors
(and predicted magnitude of influence). Potential Impact to present day Riparian Vegetation
Indication of the role the alluvial aquifer might play in this Biotic/hydrologic
interaction (see Section 3.5 for Biotic/hydrologic Interaction notes)
Key changes likely to come from the interaction between all listed stressors, with the interaction likely peaking late in the dry season (early wet season).
2D (N)
Low
(3)
2-8 m
Present day vegetation likely possesses equivalent structure/composition to the baseline state i.e. open woodland to woodland and broadly ephemeral to semi-‘mesic’ in places. However, discharge sourced augmentation (low to moderate) appears likely in parts (particularly the nothern half). Physical disturbance based modification is observed to be moderate.
Indi
rect
influ
ence
Zon
e (m
inin
g) -
SMC
allu
vial
aqu
ifer
In the Northern half of this zone; groundwater in the underlying lithology is highly unlikely to be influenced by the adjacent dewatered Wittenoom formation. Dry season propagation of dewatering within the alluvial aquifer in the adjacent zones (2A-2B) has the potential to propagate (to a low degree) upstream and through at least parts of the northern half of this Zone. Uncertainty surrounding basement-morphology/hydraulic-connectivity and its influence on this propagation is high and likely to influence the outcome. As zone 2D North is on the periphery of SMC and extends up into some of the smaller tributaries of SMC, the ability for this propogation to extend into and significantly influence hydration in such areas is likely limited. Surface water recharge events will likely have reduced residence time in the alluvials; in the order of 1-6 months (1+ months for phreatic water, 2-6 months for the bulk of vadose water). Discharge may* supplement the aquifer in the northern half of this zone. If discharge removed; propagation potential may increase.
(2) Alluvial drawdown (low to moderate (closer to 2B)), (3) Baseline Root clipping (Moderate), (4) Vegetation augmentation (Moderate), (5) 'Mesic' understorey constituents (Low to Moderate). . SMC alluvial aquifer likely providing low sustaining influence to vegetation outside the surface flow recharge events of the wet season.
Vegetation has the potential to transition from a 'semi-mesic'/'ephemeral' to generally 'ephemeral' state. Such changes would likely be accompanied by a reduction in 'canopy cover'*** in the order of 10-30% and increased mortality in the order of <5% of the overstorey population. Compositional changes within associated**** taxa are generally unlikely but possible in some cases changes in dominant**** taxa are of very low potential.
2D (S)
In the southern half of this zone; the Brockman formation will be significantly dewatered. As a result the alluvial aquifer will generally be drawn down to the point where it is inaccessible to vegetation. During the wet season, surface water flows typically lift it to a point where it is accessible for short periods of time. Surface water recharge events will likely have reduced residence time in the alluvials; in the order of 1-5 months (1+ months for phreatic water, 2-6 months for the bulk of vadose water). Discharge may* supplement.
(1) Lithological drawdown (moderate), (2) Alluvial drawdown (moderate), (6) Decreased residence time of surface water recharge events (Moderate), (7) addition of surplus water discharge (Moderate). . SMC alluvial aquifer likely providing low to negligible sustaining influence to vegetation outside the surface flow recharge events of the wet season.
Vegetation has the potential to transition to a slightly more ephemeral state (particularly at the southern end of this zone), however given that vegetation is currently broadly ephemeral such changes are likely to be minimal overall. As a result, these changes are likely to be accompanied by reduced 'canopy cover'***, in the order of 5-20% and increased mortality in the order of <8% of the overstorey population. There is some potential for compositional changes within associated**** taxa (most likely in the ground strata), with dominant taxa changes highly unlikely.
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 184
Zone
Risk
Rating
Base
line
Dept
h to
Wat
er (r
ange
)
Description of Vegetation structure/composition/modi
fication in relation to Baseline conditions Hy
drol
ogic
al
influ
ence
zone
Likely hydrological impacts Relevant to impacting or sustaining riparian vegetation
Relevant Vegetation Stressors
(and predicted magnitude of influence). Potential Impact to present day Riparian Vegetation
Indication of the role the alluvial aquifer might play in this Biotic/hydrologic
interaction (see Section 3.5 for Biotic/hydrologic Interaction notes)
Key changes likely to come from the interaction between all listed stressors, with the interaction likely peaking late in the dry season (early wet season).
3A
Low
(3)
2-8 m
Present day vegetation likely posesses equivalent structure/composition to the baseline state i.e. Woodland to Open forest and broadly semi-mesic to Mesic. Augmentation unlikely, physical disturbance based modification is low.
Indi
rect
influ
ence
Zon
e (T
own
supp
ly a
nd m
inor
min
ing
influ
ence
pot
entia
l) - S
MC
allu
vial
aqu
ifer
Groundwater in the underlying lithology will not be influenced by dewatering within the Wittenoom formation. Based on average groundwater heights just upstream and downstream of this zone; dry season propagation of dewatering within the alluvial aquifer in the adjacent zones (2C-2B) has a very low potential to propagate into parts of this zone. There is still significant uncertainty surrounding basement-morphology and the presence of any structural boundaries on the potential for drawdown to propagate within the SMC aquifer upstream of the pinch point of Kelly's pool (and into Zone 3A). Despite this, the downstream limit of this zone at Kelly's pool is attributed to evidence for a structural barrier (dolerite dyke) helping form Kelly's pool, and a basement bathtub occurring upstream of the pool (both of which should limit upstream drawdown propagation). Surplus water discharge from the Paraburdoo town waste water treatment facility may help mitigate some of this potential.
(2) Alluvial drawdown (low to negligible), (3) Baseline Root clipping (Moderate), (4) Vegetation augmentation (low to moderate), (5) 'Mesic' understorey constituents (moderate (to high in places)). . Within the dry season and in average years the SMC alluvial aquifer should provide sufficient sustaining influence to vegetation. In significant drought, upstream and downstream abstraction activities may compromise this influence.
In light of the low potential for meaningful drawdown to propagate into zone 3A (from 4East), the potential for significant 'vegetation cover' impacts are also predicted to be low. However; vegetation in the low flow channel of this zone is quite 'mesic', so hydrological sensitivity is also elevated. As a result there is potential (low) for vegetation to transition to a more 'ephemeral'/'semi-mesic' state in such areas. This would likely be accompanied by reduced 'canopy cover' in the order of 10-30%, and increased mortality in the order of <8% of the overstorey population. There is potential (low) for compositional changes within associated**** taxa to occur (most likely in the Mid or Ground strata); with dominant taxa changes highly unlikely.
3B
Low
(3)
2-8 m
Present day vegetation Likely posesses equivalent structure/composition to the baseline state i.e. open woodland to woodland and broadly Ephemeral (to semi-Mesic in places). Discharge sourced augmentation is considered unlikely although possible in places. Physical disturbance based modification is observed to be low.
Indi
rect
influ
ence
Zon
e (m
inin
g) -
SMC
allu
vial
aqu
ifer
Underlying lithology is highly unlikely to be influenced by drawdown in the Brockman formation upstream. The SMC alluvial aquifer will generally be out of reach of riparian vegetation which at the northern end will be partly a result of alluvial drawdown in zone 1B-2D. Towards the southern end of this zone the SMC alluvial aquifer is potentially accessible to mature trees. Seasonal surface water flows will provide temporary recharge and some potential mitagative influence (minimal). Surface water recharge in the alluvials will likely have moderate residence time in the order of 2-8 months (1-2 months for phreatic water, 2-8 months for the bulk of vadose water). Discharge may* supplement once relocated.
(2) Alluvial drawdown (moderate to low), (6) Decreased residence time of surface water recharge events (Low), (7) addition of of surplus water discharge (Moderate to Low). . Outside the surface flow recharge events of the wet season, there is low potential for vegetation to be sustained by to access the SMC alluvial aquifer.
Increasing upstream drawdown of the alluvial aquifer (in zones 1B and 2D (S)) may be accompanied by reduced alluvial aquifer access by vegetation in this zone. As a result there is potential for the vegetation in this zone to transition to a slightly more ephemeral state. However; given that vegetation is currently broadly ephemeral such changes are likely to be minimal overall. There is low potential for significantly reduced 'vegetation cover', but reduced 'canopy cover'*** in the order of 5-20% is likely. In addition, increased mortality in the order of <5% of the overstorey population would potentially occur. There is potential for compositional changes within associated**** taxa (most likely in the Mid and Ground strata), with dominant taxa changes highly unlikely.
* Surplus mine water discharge from the Paraburdoo Mine is proposed to be relocated to south of the range (to Joes crossing); if so removal of discharge from the current outlet is likely reduce water availability in the alluvials within Zones 1A, 2A, 2B, especially in light of the proposed hydrogeological changes. Vice versa; discharge relocation to Joes crossing will provide some mitigation to vegetation in zones 2D (south) and 3B once relocated. The timing of this relacation is still unclear and so impacts which may be associated with this relacation have similar uncertainty. Despite the relocation, there is still good potential for small amounts of discharge to be maintained into the current discharge area from the adjacent wet plant and turkeys nest.
** Changes to 'vegetation cover' in the form of structural changes within one of the three traditional strata (Upper, Mid and Ground; as per NVIS vegetation 'association' level) by one (or more) structural formation class. This generally involves a negative transition from any of the following cover abundance classes/ranges to the adjacent lower class/range; 0-2%, 2-10%, 10-30%, 30-70% used to attribute/describe vegetation structure.
See more Over Page:
Riparian Vegetation and Associated Groundwater Dependent Ecosystems – Targeted Survey of the Greater Paraburdoo Operations Greater Paraburdoo Iron Ore Proposal 185
*** Changes to 'Canopy Cover' in the form of reduced Leaf Area Index (LAI), reduced huber value, reduced canopy stature and height are all generally associated with changes to the canopy which invole modification of the individuals present rather than larger scale removal/death of individuals as implied to occur in situations of 'vegetation cover'** change associated with stronger magnitude water stress. However; broader changes in canopy characters will invariably be associated with small scale increases in mortality within the overstorey population. Where increased mortality impacts associated with longer term reductions in canopy cover are predicted in the above table, the increases are indicative of stratum mortality above and beyond that which naturally occurs within similar fluvial systems under average degrees of climatic variability.
**** A compositional change to the dominant species assemblage for a particular vegetation association (in this study refferd to as Vegetation Types) infers that one or more of the species listed as dominants within any of the relavant vegetation strata reffered to in the vegetation description (and thus interpreted to be a dominant component of the vegetation), may be impacted to the point where it no longer persists (or can be detected) within the relevant vegetation. Alternatively changes to the 'associated species' assemblage only relates to potential for removal of any species commonly recorded (in at least 2 baseline sampling points) in the vegetation association in question.
