Attachment C - Stormwater Management Plan - 30-32 Doonella Street_SMP-revA_full (00016826)

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2 Stormwater!Quality!
2.1 Design!Objectives!
This! report! identifies! the! stormwater! quality! management! objectives! for! the!
operational! phase! (post"construction! phase)! of! the! proposed! development.!!
Construction! based! stormwater! quality! management! objectives! will! need! to! be!
addressed!as!part!of!Operational!Works!application.!
The! load! based! Water! Quality! Objectives! (WQO’s)! stipulated! in! the! State! Planning!
Policy!–!July!2014!for!the!South!East!Queensland!region!will!be!adopted!for!the!site.!!
The! applicable! water! quality! design! objectives! for! the! site! are! shown! in! Table! 1!
below.!!!
Table!1:!Site!stormwater!quality!objectives!(operational!phase)!

       Minimum!reductions!in!mean!annual!loads!from!unmitigated!development!(%)!
    Total!Suspended!     Total!Phosphorous!          Total!Nitrogen!!      Gross!pollutants!!
      Solids!(TSS)!             (TP)!                     (TN)!                >5!mm!
          80!                    60!                       45!                    90!

2.2 Stormwater!Quality!Treatment!
2.2.1 Strategy!
The! objective! of! this! report! is! to! assess! the! stormwater! quality! measures! required!
based! on! the! proposed! layout! and! is! prepared! in! order! to! support! the! Material!
Change!of!Use!(MCU)!application!for!the!site.!!The!treatment!train!for!the!proposed!
development!consists!of!runoff!from!the!roofed!area!being!collected!in!a!rainwater!
tank!for!re"use!on!site.!!Overflows!from!the!tank!and!all!other!collected!runoff!will!be!
directed! to! a! central! bioretention! system! (and! detention! tank)! located! near! the!
outlet! of! the! site! prior! to! discharging! from! the! site! to! the! drainage! system! in!
Doonella! Street.! ! A! small! catchment! associated! with! the! driveway! down! to! the!
basement!carpark!will!bypass!the!bioretention!area!due!to!the!level!difference.!!!!

2.3 Modelling!Approach!
2.3.1 MUSIC!Parameters!
An! assessment! of! stormwater! runoff! quality! from! the! proposed! development! site!
has! been! assessed! using! the! Model! for! Urban! Stormwater! Improvement!
Conceptualisation!(MUSIC)!–!Version!5.16,!released!in!2013.!!!
Climate!data!for!the!catchment!was!sourced!from!the!MUSIC!model!database.!!The!
rainfall! and! evaporation! data! template! for! this! site! has! been! based! on! data! from!
Cooroy!from!1/1/1973"!31/12/1983!with!six!(6)!minute!rainfall!duration.!

Table! 2! and! Table! 3! outline! the! adopted! source! node! parameters! from! “MUSIC'
Modeling'Guidelines”!(Water!By!Design,!2010)!that!were!used!in!the!MUSIC!model.!!!
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