Large trees Trees within the Construction Deep-rooted tree species in that may project boundary areas of shallow Precinct 1 access are not groundwater should be (tunnels between groundwater considered to be identified and their CBD and groundwater dependence on Domain stations) dependent (see groundwater should be Linlithgow – Technical assessed. If found to be Avenue shaft Appendices R groundwater dependent, the construction and S). Trees trees within the area of Precinct 6 - CBD outside the drawdown should be South station project boundary irrigated throughout the have not been period of drawdown Precinct 8 - assessed but Eastern portal trees in low lying areas such as near watercourses or waterbodies are considered potentially groundwater dependent Beneficial Moderate risk of Construction Likely to involve further uses of impact on third investigation and/or Precinct 1 - groundwater party properties mitigation measures, for Tunnels at third party based on land example: CBD North properties use, presence of Site specific risk station to CBD degraded by Groundwater assessment of South station migration of Quality contaminant location contaminant Restricted Use Domain station to and concentrations plumes Zones and/or eastern portal Use of temporary anthropogenic (shaft in recharge or discharge contaminants corner of bores to prevent within predicted Fawkner Park) contaminant migration area of impact Precinct 2 - Minimisation of Western portal drawdown through Precinct 3 - Arden construction techniques station such as construction using a TBM or Precinct 4 - grouting of the tunnels Parkville station Precinct 5 - CBD station Precinct 8 - Eastern portal
Large trees that may access groundwater Trees within the project boundary are not considered to be groundwater dependent (see Technical Appendices R and S). Trees outside the project boundary have not been assessed but trees in low lying areas such as near watercourses or waterbodies are considered potentially groundwater dependent Construction Precinct 1 (tunnels between CBD and Domain stations) – Linlithgow Avenue shaft construction Precinct 6 - CBD South station Precinct 8 - Eastern portal Deep-rooted tree species in areas of shallow groundwater should be identified and their dependence on groundwater should be assessed. If found to be groundwater dependent, the trees within the area of drawdown should be irrigated throughout the period of drawdown Beneficial uses of groundwater at third party properties degraded by migration of contaminant plumes Moderate risk of impact on third party properties based on land use, presence of Groundwater Quality Restricted Use Zones and/or anthropogenic contaminants within predicted area of impact Construction Precinct 1 - Tunnels CBD North station to CBD South station Domain station to eastern portal (shaft in corner of Fawkner Park) Precinct 2 - Western portal Precinct 3 - Arden station Precinct 4 - Parkville station Precinct 5 - CBD station Precinct 8 - Eastern portal Likely to involve further investigation and/or mitigation measures, for example: Site specific risk assessment of contaminant location and concentrations Use of temporary recharge or discharge bores to prevent contaminant migration Minimisation of drawdown through construction techniques such as construction using a TBM or grouting of the tunnels
MMRP_Chapter-18_Groundwater.docx