Impacts App Table 1. Activities in CSG and LCM development that potentially impact on GDEs. These activities present risks to GDEs that include altering the number of native species and species composition within GDE communities; disrupting ecological processes that deliver ecosystem services; damage aquifer geologic structure; increasing risk of exotic species invasion; removing GDE habitat; altering groundwater quality; and changing timing, duration, pressure and flow conditions of groundwater Impacting activity Type of impact Type of GDE When does this impact need to Factors to consider during affected be considered in EIA? impact assessment Aquifer dewatering Watertable All Aquifer connection to surface Magnitude, duration, lowering; change GDE; aquifer likely to have frequency, and timing of timing and stygofauna (alluvial, karstic, dewatering; how these magnitude of calcrete) with dewatering at a compare to pre-impact groundwater level magnitude and duration outside conditions fluctuations natural variability Initial watertable depth; water level fluctuation range over annual and timescales, amplitude and rate of change Watertable lowering will it – convert gaining stream/wetlands to losing ones? Aquifer Loss of artesian Springs Depressurisation of an aquifer Lost pressure; alteration of depressurisation pressure connected to a spring discharge flow rate to spring Flow rate changes affect water level, permanence, and spring water quality Excavation of Removal of upper All GDE types When overburden is an aquifer Watertable in overburden aquifer that supports GDEs overburden; aquifer porosity Alteration of subsurface flow paths with excavation Surface Alter groundwater Vegetation; Major landscape changes such as Alteration to channelling of topography changes recharge patterns wetlands; excavation of mine pit; water to or from aquifer river baseflow; subsidence of longwall panels recharge zones; availability of aquifer GDEs groundwater modelling Potential flow changes considered in groundwater modelling If GDEs have some level of reliance on surface water diversion Disconnect river River baseflow; If connection exists between If the diverted reach is and aquifer aquifer GDEs channel and aquifer dependent on groundwater, either locally or upstream
Impacts App Table 1. Activities in CSG and LCM development that potentially impact on GDEs. These activities present risks to GDEs that include altering the number of native species and species composition within GDE communities; disrupting ecological processes that deliver ecosystem services; damage aquifer geologic structure; increasing risk of exotic species invasion; removing GDE habitat; altering groundwater quality; and changing timing, duration, pressure and flow conditions of groundwater Impacting activity Type of impact Type of GDE affected When does this impact need to be considered in EIA? Factors to consider during impact assessment Aquifer dewatering Watertable lowering; change timing and magnitude of groundwater level fluctuations All Aquifer connection to surface GDE; aquifer likely to have stygofauna (alluvial, karstic, calcrete) with dewatering at a magnitude and duration outside natural variability Magnitude, duration, frequency, and timing of dewatering; how these compare to pre-impact conditions Initial watertable depth; water level fluctuation range over annual and timescales, amplitude and rate of change Watertable lowering – will it convert gaining stream/wetlands to losing ones? Aquifer depressurisation Loss of artesian pressure Springs Depressurisation of an aquifer connected to a spring Lost pressure; alteration of discharge flow rate to spring Flow rate changes affect water level, permanence, and spring water quality Excavation of overburden Removal of upper aquifer All GDE types When overburden is an aquifer that supports GDEs Watertable in overburden; aquifer porosity Alteration of subsurface flow paths with excavation Surface topography changes Alter groundwater recharge patterns Vegetation; wetlands; river baseflow; aquifer GDEs Major landscape changes such as excavation of mine pit; subsidence of longwall panels Alteration to channelling of water to or from aquifer recharge zones; availability of groundwater modelling Potential flow changes considered in groundwater modelling If GDEs have some level of reliance on surface water diversion Disconnect river and aquifer River baseflow; aquifer GDEs If connection exists between channel and aquifer If the diverted reach is dependent on groundwater, either locally or upstream
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