A6107 Lot9 Stormwater Management Plan (RevB) June 2022 · OPW22/0166

any significant risk to RIP function, groundwater quality or water quality in
the POSCW and surrounding areas.

Main roofed areas from both buildings will drain to a Rainwater Harvesting
Tank of 80,000 litre capacity with captured runoff utilized for landscape
irrigation. Tank overflow will be directed to catchment specific RIPs.

Runoff from main landscaped areas will be intercepted and conveyed via a
landscaped swale located along the site’s western boundary to a series of RIPs
and shallow landscaped basin at the south-western corner of the site.

 RIPs will be aggregated within the basin and flows greater than the 1% AEP
major design event will be directed toward the POSCWP as dispersed sheet
flow via a broad weir.

Refer to engineering drawings at Appendix A for details.


5.0    RAPID INFILTRATION PITS (RIP’s)

RIPs consist of a bottomless stormwater pit which promotes infiltration
through its base.

Crushed rock and multiple layers of geofabric and “sacrificial sand” are
installed at the base of the RIP to protect against clogging of dune sands
below.

RIPs are subject to routine inspection and maintenance by the building’s body
corporate as part of the building’s Community Management Scheme and such
maintenance is critical to their ongoing function. (Refer Maintenance Schedule
at Appendix B).

RIPs have been installed on all previous stages of Settlers Cove and proven to
work very well.

Refer engineering drawings at Appendix A for RIP details.




6.0    CALCULATIONS

       6.1    RIP Infiltration (100year ARI events)



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A6107/L9/SMP/RevB/Jun 2022                                                   Page 4 of 7
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                       Brah101 Pty Ltd t/as ALTA PROJECTS