Stormwater Management Plan -OPW (A) · OPW25/0042

3.0    PROPOSED DEVELOPMENT

The proposed development consists of multi storey hotel buildings with basement carparking
and all buildings to be surrounded by extensive landscape areas, both hard and soft. The
northern face of the development provides for two (2) swimming pools; one at the eastern end of
the site surrounded by hardstand and landscaping and a second ‘quiet pool’ at the western end
of the site with predominantly soft-landscaped surrounds.

An ephemeral stream will provide a suitable route for conveyance of external catchment flows
through the site with minor events piped and emergency major event flows conveyed as
overland flow.

Guests’ vehicular entry to basements will be from Banksia Avenue while service vehicles will
access back of house areas via the cul-de-sac bowl at the end of Serenity Close.

Refer architectural drawings at Appendix C.


4.0    COUNCIL CONDITIONS

      46. Stormwater Drainage
      1.   Prior to the lodging of a development application for Operational Works, provide and
           have endorsed by Council updated architectural plans, preliminary engineering plans,
           and Stormwater Management Plan, which addresses the following:
           a.    Acceptance of all external catchments
           b.    Provide sizing and nominate the locations of roofwater harvesting tanks. The tanks
                 are to be sized to provide 80% reliability to supply water for landscape irrigation
                 and flushing of toilets in public/communal areas of the resort
           c.    Provide a method of removal of gross pollutants from all surface runoff (eg litter
                 baskets)
           d.    Provide treatment of internal site runoff such that the pollutant removal
                 requirements of AO6.1 and AO6.2 of the Water Quality and Drainage Code are
                 achieved prior to discharge to surface waters or infiltration to groundwater. Provide
                 MUSIC modelling to demonstrate this will be achieved by the proposed stormwater
                 treatment train
           e.    Provide in-situ hydraulic conductivity testing at the locations and depths nominated
                 for Rapid Infiltration Pits and demonstrate that the assumptions regarding
                 infiltration rates will be achieved. If not achievable, provide a revised design.
           f.    Ensure the proposed method of stormwater management achieves no net
                 reduction of rainwater infiltrating the sand dunes beneath the site. This may be
                 achieved either by infiltrating all flows up to the 10%AEP or by alternative
                 measures designed and managed in accordance with a groundwater recharge and
                 discharge management plan prepared by a suitably experienced and qualified
                 groundwater hydrologist. The groundwater recharge or discharge must
                 demonstrate that the development does not affect groundwater balances beyond
                 the property boundaries.
           g.    Updated the maintenance and management plan of the Stormwater Management
                 Plan to reflect any changes.

      __________________________________________________________________________
      A6769/25/SWMP/Rev OpW(A) – Feb 2025
      SH/PL                                                                                Page 2 of 9
                  Brah101 Pty Ltd t/as ALTA PROJECTS