06/0823 - Applicant's Response to Information Request including Attachments [As Published] · 132006.823

Erosion & Sediment Controf

 

64.

65.

65.

Please provide a month by month plan of works detailing the level of disturbance for each
stage/month. It is recommended that plans showing the progressive development of the site
and the controls that will be in place for each stage be submitted. Details on the
decommissioning of sediment basins as stages are completed should also be provided.

. The earthworks sequence has been developed between the applicant and its consultants

QANTEC McWILLIAM. The basis of the design is that in the four areas of work, a sequence
will be established whereby all underground services for drainage, water and electrical mains
will be installed prior to general bulk earthworks to that zone. The bulk earthworks
component of the earthworks package will include cut and fill (where required) to that zone
with immediate installation of basecourse to building platforms and on road ways basecourse,
kerbs and one coat seal. This will give all weather access to building platform and allow
clean removal of foundation spoil. This regime of construction should result in minimising silt
runoff into silt retention ponds.

The earthworks will be sequential and disturbance of existing surface will not occur until
previous areas have been stabilised with basecourse and/or hydromulch or turfing as may be
required.

Attachment 21 contains plans detailing the staging of Civil Works.

The regime to control this work will be as was recently successful on the site stabilisation
work. The applicant's on-site representative will hold a weekly review meeting with Council
Officers and will then instruct the Contractor on any issues that the Council has raised.

The strategies proposed in the Bayview Noosa Hydrology and Stormwater Management Plan
prepared by WBM Oceanics Australia were not sufficient to contro! the level of sediment
leaving the site in small rain events and water quality objectives were not always achieved.
Please detail any further measures that are proposed for the new proposal.

It is noted that WBM’s report, titled Bayview Noosa Hydrology and Stormwater Management
Plan was not prepared to manage construction stage erosion and sediment control. Rather,
erosion and sediment control was to be effected under the Sediment and Erosion Control
Implementation Management Plan.

Nonetheless it is acknowledged that the construction contractor (Hollands) did not undertaken
work in accordance with the recommendations of this report.

Upon reflection of this previous shortcoming, a revised set of Erosion and Sediment Control
drawings have been prepared for the current proposal. It is expected that controls
tepresented within these drawings will result in better outcomes for the following reasons:

+ There will be 5 phases of bulk earthworks and civil works to ensure that works
are focused within a defined site extent. This will limit the extent of works
occurring on site at any on time. This will have benefits in limiting the amount of
exposed ground as well.

+ All upslope runoff will be either diverted or piped under the development area
Prior to majority of the bulk earthworks and civil works occurring.

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