Client Ref:
City of Darebin
Site Address:
42 James Street, NORTHCOTE, VIC 3070
Site Inspection and comparison of photographs
A site inspection of the subject land was carried out by Stephen Muldoon, Senior Forensic Engineer at
FMG, on 13 October 2021, in the presence of the City of Darebin representative s.33(1)
. The
owners of 42 James Street (Simon) and 3 Campbell Grove (Jason) were present at the beginning of the
inspection.
FMG notes the following relevant information following a comparison of the photographs from the
most recent inspection against those taken during the previous inspections:
•
Significant vegetation growth has occurred between November 2020 and October 2021,
hence it was difficult to compare all areas of the subject land.
•
It is unclear as to whether erosion of the steep slope to the eastern end of the subject land,
directly adjacent to the existing concrete crib retaining wall has occurred between November
2020 and October 2021 [5 – 6]. However localised erosion of the land has occurred since April
2019 [2 – 6].
•
Erosion of the ground has occurred between November 2020 and October 2021, to the
western end of the subject land, adjacent to the concrete retaining wall at the north-west
corner of 1 Campbell Grove, Northcote (retaining wall located at the north-east corner of 1A
Campbell Grove, Northcote) [7 – 12].
•
Erosion / movement of the land along the southern side of the subject land (i.e. adjacent to
the northern boundaries of 1 and 3 Campbell Grove, Northcote) does not appear to have
occurred. Localised outcrops of rock are currently visible in this area, similar to November
2020, with no evidence of loose / displaced soil at the toe of the rock outcrops [13 – 17].
•
No evidence of movement and / or damage to the brickwork wall along the south boundary
of 42 James Street, at the top of the battered ground to the subject land [18 – 20].
Along with the above, during the recent inspection, a localised void was evident beneath the south-east
corner of the property boundary to 42 James Street, with the void appearing to extend beneath the
south-west corner of property to the east of 42 James Street [21]. FMG notes that this void was evident
during the inspection in November 2020, however it is unclear as to whether this void has increased in
size. Based on the location of the void, stormwater run-off can enter the void and enter beneath the
property at 42 James Street and the neighbouring site to the east.
Based on the above, it is FMG’s opinion that localised erosion of the ground to the eastern and western
ends of the subject land has occurred between November 2020 and October 2021.
FMG Ref: 273632 - S44580
Page 2 of 22
Client Ref:
City of Darebin
Site Address:
42 James Street, NORTHCOTE, VIC 3070
Proposed rectification works
FMG previously provided the City of Darebin with 3no. site retention options for the subject land via
email on 22 April 2021. FMG provided the following options to the City of Darebin (refer to sketches
SK01 to SK03, dated 22 April 2021, in Appendix B for more information):
•
Option 1 – Installation of a permanent stabilised batter
The batter would be required to be given a uniform fall, with a maximum slope of 30o. A
shotcrete capping could then be installed over the batter to prevent erosion of the batter.
New surface and sub-surface drainage would also be required.
•
Option 2 – Installation of retaining walls to create usable space for 3no. properties (retaining
wall option A)
Install a retaining wall in an east-west direction, starting adjacent to the existing concrete
retaining wall at the top of the batter and extend the wall across to the existing crib wall at the
bottom of the batter. A second retaining wall can then be installed in a north-south direction
from the first retaining wall to the corner of the property at 42 James Street, Northcote.
•
Option 3 – Installation of retaining walls to create usable space for 3no. properties (retaining
wall option B)
Install a retaining wall in an east-west direction, starting adjacent to the existing concrete
retaining wall at the top of the batter and extend the wall east. The wall would then change
direction and extend north, towards the property at 42 James Street, Northcote
Following discussions with the owners of 42 James Street and 3 Campbell Grove, their main concern is
that erosion / movement of the subject land is continuing to occur, which may cause damage to their
properties in the future if not addressed. FMG understands that remediation works that will address
the long-term stability of the subject land is their main concern and that creation of usable land for
the various properties is not considered to be a key factor in the remediation of the subject land.
Based on the above, it is FMG’s opinion that Options 1 and 2 would be the most suitable remediation
options for the subject land. FMG previously issued a letter (ref: 273632 – S44580, dated 21
September 2021) that outlined the benefits and constraints associated with each option. In summary,
it is expected that that works involved with Option 1 will be simpler to undertake (both economically
and physically), however the land will remain unusable following the works as there would be a slope
to the land with a concrete topping to it, so it couldn’t be used for car parking, garden areas etc.
Whereas Option 2 will result in usable land being created for the adjoining properties, however the
expected works involved are more extensive and intrusive than the work required for Option 1.
FMG Ref: 273632 - S44580
Page 3 of 22
Client Ref:
City of Darebin
Site Address:
42 James Street, NORTHCOTE, VIC 3070
FMG notes that alterations could be made to Option 2 to create usable land for 42 James Street only,
with no usable land created for 1 and 3 Campbell Grove. Stepping the height of the retaining wall in
different areas to suit the natural ground levels could be undertaken and then regrading of the land to
the east of 42 James Street could be undertaken to reduce the extend of the remediaiton works if
required.
FMG notes that the attached Options are schematic remediation options only and further
geotechnical investigations will be required to be undertaken along with structural design and
documentation to determine the exact nature of the remediation options required. The proposed
remedation solutions may change depending on the additional information obtained during the
geotechnical investigation and final design process.
Recommendations
As outlined above, it is FMG’s opinion that localised erosion of the ground to the eastern and western
ends of the subject land has occurred between November 2020 and October 2021. Whilst FMG did
not observe any evidence that there is a risk of an imminent collapse of the subject land, FMG
recommends that the City of Darebin undertake remediation works to the land as soon as practically
possible to ensure that further deterioration of the land does not occur, which may result in a
destabilisation of the land and potential localised collapse of the land and damage to the adjoining
properties.
FMG notes that it is expected that the processes involved in deciding upon and implementing the
proposed remediation solution will occur in the coming months. Therefore, FMG recommends that
the City of Darebin implement an on-going monitoring process of the subject land, until such a time
that the remediation works commence, to assess the condition of the land and to ensure a significant
deterioration of the land does not occur in this timeframe. FMG recommend that the subject land is
inspected on a regular basis (i.e. monthly) and a comparison of the photographs from these
inspections is undertaken against photographs from the previous inspections to assess the condition
of the land.
If significant deterioration is identified, FMG notes that urgent make-safe / stabilisation works may be
required to be undertaken to prevent damage to the adjacent properties.
FMG Ref: 273632 - S44580
Page 4 of 22
Client Ref:
City of Darebin
Site Address:
42 James Street, NORTHCOTE, VIC 3070
© Koukourou Pty Ltd trading as FMG Engineering
The work carried out in the preparation of this document has been performed in accordance with the requirements of FMG
Engineering’s Quality Management System which is certified by a third party accredited auditor to comply with the requirements
of ISO9001.
This document is and shall remain the property of FMG Engineering. The document is specific to the Client and site detailed in
the document. Use of the document must be in accordance with the Terms of Engagement for the commission and any
unauthorised use of this document in any form whatsoever is prohibited. No part of this document including the whole of same
shall be used for any other purpose nor by any third party without the prior written consent of FMG Engineering.
The opinions expressed in this document are based upon a visual inspection conducted with reasonable care. Areas not reasonably
accessible and not readily viewed without disturbing the existing structure, finishes or furnishings have not been inspected, unless
noted otherwise.
FMG Engineering has not carried out a review with respect to combustibility, fire resistance or fire safety provisions of the external
insulation and finishing system, wall panelling, cladding or façade material or any associated fixing system that is to be or that
may be applied to this project. Cladding systems must comply with the Building Code of Australia, the NCC, relevant Australian
Standards and any other applicable regulations and test requirements. FMG advises that project specific advice with respect to
fitness for purpose and statutory compliance of any proposed cladding materials shall be sought from a suitably qualified and
experienced Materials or Fire Services Engineer.
FMG Engineering reserves the right to append, amend and / or modify the contents of this document upon receipt of additional
information.
The document is not a guarantee or warranty, but is a professional assessment of the condition of the premises, or part thereof,
at the time of inspection.
Document Status
REV
AUTHOR
REVIEWER
ISSUE DATE
Stephen Muldoon
Anthony Perkin
0
BEng MIEI
BEng CEng MIEI MIEAust CPEng NER
15 October 2021
Senior Forensic Engineer
Senior Forensic Engineer
FMG Ref: 273632 - S44580
Page 6 of 22
Client Ref:
City of Darebin
Site Address:
42 James Street, NORTHCOTE, VIC 3070
Appendix A
Photographs
Client Ref:
City of Darebin
Site Address:
42 James Street, NORTHCOTE, VIC 3070
Appendix B
Sketches
