RFI - Appendix B Civil Engineering Report · MCU22/0038

 12 May 2022




A bioretention basin will be located along the southern boundary of the site with bypass flows
discharging to the existing stormwater in the south east corner of the site. The treated flows only
will connect to the basement drainage system for pump out to the external drainage system. This is
required due to the high invert levels of the existing external stormwater network. No other flows
other than the treatment flows from the bioretention basin subsoil drains will connect to the
basement drainage system for pump out.

The basement pump system will consist of a new tank under the basement slab with submerged
pumps. The pumps and tanks will be accessed from within the basement via access cover. As the
only flows that will enter this system from the bioretention basin are the treatment flows, the flows
will be minimal. The size of the tank and pumps required will be confirmed at detail design and part
of any required operational works and plumbing applications.

The pump out system and tanks will have no impact on the basement layout.

A bioretention basin will be located on the western boundary of the site with bypass flows
discharging to the existing stormwater in the north west corner of the site. The treated flows and
overflows will discharge to the existing external network.

Stormwater treatment will be implemented to remove sediments, nutrients, gross pollutants and
hydrocarbons in accordance with the requirements of Noosa Council and the State Planning Policy.

Stormwater discharged from site is proposed to be consistent with the existing commercial
development discharge. This development sits within a lot that has been allowed for in previous
stormwater calculations with the overall Noosa Civic and Noosa Business Centre discharging to
large overland flow paths and creeks, therefore no detention is proposed for this development as
per the existing centre.

The proposed conceptual stormwater drainage layout is depicted on MPN Plan 8662-CP.1.01
attached in Appendix 3.


4.5.2 Stormwater Quantity Management Strategy

The proposed development site will connect into the existing drainage system for the Noosa Civic
Shopping Centre and Hofmann Drive drainage system. The sites minor flows will run through the
existing pipe system whilst the major overflows will overland flow down the internal roads prior to
discharging to the creek to the south of the site in accordance with the overall Noosa Civic and
Noosa Business Centre development. There will be no impacts to external properties as a result of
the development flows through the internal site system.

The proposed development site has existing stormwater infrastructure which will be utilised for
the Medihub development, with additional stormwater pits constructed as part of the subdivision
works currently under construction.




 Excellence with Economy in Engineering                                                                 9
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