Attachment 3 - Revised Engineering Report (rec. 7.04.2025) MCU24-0165 & OPW24-0222

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4       Earthworks
The existing site grades away from School Street sloping towards the drainage channel towards the
rear of the lot. The internal site levels range between 89.2m AHD to 91.1m AHD, with the high point
located in the north-western corner of the site.
The site is predominantly nominated for filling works to achieve compliance with flood levels, therefore
retaining walls have been proposed along the site boundary as detailed on the design drawings.
All cutting and filling are to be carried out in accordance with AS3798 Guidelines on Earthworks for
Commercial and Residential Developments. Any site filling required will be from site spoil (subject to
Geotechnical Investigation), provided it meets the requirements of AS3798 and is placed with controlled
compaction.
Impacts of proposed earthworks on overland flow conditions will not adversely affect adjacent or
downstream properties. Proposed earthworks will not encroach on adjacent properties or affect the
function of stormwater catchments external to the site.
All construction activities, including Erosion and Sediment Control (ESC) methods, would be managed
under the control measures of a Construction Environmental Management Plan (CEMP) for the
development site. The CEMP and ESC plans would be prepared for submission with the future
application for Operational Works Approval.



5       Stormwater Management
5.1     Existing Catchment
The existing site catchment drains to the rear into the environment management and conservation lot
(22 Rifle Street). A drainage channel is located south of this lot along Rifle Street which conveys flows
from the west to a culvert structure east of the development site. The subject do not directly drain to
this channel due to a high bund on the development side of the channel, however, flows generally head
easter towards Creek Street and other environmental management and conservation lots. The wider
catchment conditions are shown in Figure 3.




FIGURE 3: EXISTING STORMWATER NETWORK (SOURCE: NSC MAPPING)




 15 November 2024                                                                                          Page 6