Compiled Approved Plans OPW25/0042.02

                               3. All infiltration devices to be located within the “residential high density
                               building envelope” as shown on Ken Hicks and Associates drawing 1128
                               Master.
                               4. Surcharge runoff from storms greater than the capacity of infiltration
                               devices to be directed toward ecological restoration areas and roadways as
                               dispersed sheet flow rather than concentrated flows.
                               5. Stormwater runoff from landscaped and hardstand areas to be pretreated
                               prior to infiltration.
                               6. Runoff from roadways and landscaped areas to be directed to landscaped
                               swales or ephemeral streams for biological treatment including vegetative
                               plantings in accordance with the Landscape Master Plan.
                               7. Areas of swales and ephemeral streams shall be lined with a soil layer to
                               retard infiltration and allow biological treatment of runoff. Soils will be
                               remediated by mixing with loams to achieve a hydraulic conductivity of
                               100mm/hr.
                               8. Swales and ephemeral streams to be planted in accordance with approved
                               Landscape Master Plan in order to promote biological treatment of runoff.


                     Consequently, and in order to counteract the effect of significant impervious
                     areas being constructed, the design approach will see stormwater runoff from
                     the proposed development’s roofs, hardstand and landscaped areas
                     infiltrated into the natural sands via a series of Rapid Infiltration Pits (RIPs)
                     and a consolidated Rapid Infiltration Culvert (RIC) in order to achieve no net
                     reduction in rainwater infiltration.

                     Discrete RIPs are to be located along the northern and eastern edges of the site
                     accepting runoff from relatively minor nearby impervious and landscaped
                     areas.
                      Treatment of runoff prior to infiltration by RIPs will be via small bioretention
                     basins adjacent individual RIPs with low flows (< 3 month ARI) directed to
                     the bioretention surface.

                     Major event surcharge of RIPs would be directed to adjacent roadways (legal
                     point of discharge) as dispersed overland flow.

                     Runoff from approximately 7,532m2 (80%) of roofed areas will be piped to the
                     abovementioned rainwater harvesting tank at the south-western corner of the
                     site with tank overflow discharging to an adjacent Bioretention Basin and
                     Rapid Infiltration Culvert (RIC).

                     A weir and splitter pit arrangement will be employed within the tank such
                     that flows of 3 month ARI or lower will be directed to the bioretention basin
                     surface for formal treatment with larger event flows piped directly into the
                     RIC.

                     __________________________________________________________________________

                     A6769/25/SWMP/Rev OpW(A) – Feb 2025
                                                                                                      Page 6 of 9
                     SH/PL
                                                  Brah101 Pty Ltd t/as ALTA PROJECTS
Document Set ID: 24143616
                  23646596
Version: 1, Version Date: 24/09/2025
                          21/03/2025