Applicant's Information Response

The submitted information does not include a geotechnical report for the subject site, nor an Acid
Sulphate Soils Management Plan.”

Information Required

    19. Provide a site-specific Geotechnical Investigation Report, prepared by a suitably qualified
        person* that addresses, in particular (but not limited to):
            a. the impact of excavation and the construction works on the stability of nearby
               building and infrastructures;
            b. details of the proposed retaining structures;
            c. section plans indicating the location of the retaining structures and foundations
               in relation to the property boundary, the building pad, finished floor levels, etc.;
            d. the structures required to collect and convey existing overland flows that are
               impacted on by the construction of the retaining structures;
            e. any fencing to be installed on top of or beside the retaining structures;
            f. the location of any services, above or below ground, adjacent to the proposed
               retaining structures.
    20. Provide a plan of the proposed temporary and permanent structural systems and their
        construction methodology. Please note that the system must not rely on temporary or
        permanent anchors extending beyond the property boundary unless written authority
        from the land owners or controlling authority are provided.
    21. Provide a site-specific Acid Sulfate Soils investigation, including recommendations for the
        management and treatment of potential acid sulfate soils.

Applicant’s Response
A Geotechnical Investigation Report has been prepared by Tectonic and is included in Attachment F.

With regard to item 20, a preliminary design for car park level is provided on engineering plan
A6035/21/R08. This preliminary design has been reviewed by Tectonic and a letter confirming that it is
consistent with the advice in the Geotechnical Report is included in Attachment G.

An Acid Sulfate Soils Assessment has been prepared by Tectonic in response to item 21 and is included
in Attachment H.

STORMWATER

Council Issue - Water Quality Management

“PO1 of the water quality and drainage code requires development is planned and designed having
regard to the natural features of the site, to avoid impacts to ecologically important areas and
effectiveness of sediment and erosion control measures during construction. Runoff from this
development drains directly to Lake Doonella, an area of High Ecological Significance.

The development includes for the water quality treatment features, i.e. sediment basin and basins to be
located mid way along the eastern property boundary. In both construction and operation this will
necessitate a large area of the site to drain uphill for waters to be treated prior to leaving the site.

Minimum sediment and erosion control objectives for all development are detailed in Appendix 2 of the
State Planning Policy, and are guided by the International Erosion Control Association Best Practice Book
Series. In addition to water draining uphill, the proposed sediment and erosion control design does not
demonstrate that it will be possible for the construction phase stormwater management design
objectives included in Appendix 2 of the State Planning Policy to be practically incorporated into the
construction.

Construction for the bio-retention basin, as well as other drainage pipework footings etc. for the site will
necessitate excavations below the elevation of 5m AHD, which triggers the need for assessment of Acid
Sulphate Soil impacts.