OPW16/0021- Operational Works Application 2 of 4

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7 Conclusions!
It! can! be! seen! from! the! results! presented! in! Table! 6! that! the! treatment! train!
proposed! for! the! development! achieves! the! performance! criteria! set! by! the! NSC.!!
Annual! Load! Reductions! of! Total! Suspended! Solids! (TSS),! Total! Nitrogen! (TN)! and!
Gross!Pollutants!(GP)!have!been!met.!!
A!detention!system!consisting!of!a!Stormwater!Tank!and!a!detention!basin!tanks!is!
proposed!on!the!site!in!order!to!achieve!Council’s!nonZworsening!criteria.!Table!14!
provides!a!comparison!of!the!peak!existing,!developed!and!mitigated!flows.!!It!can!
be!seen!that!whilst!peaks!flows!increase!under!the!developed!scenario!in!Catchment!
2,!the!modelled!detention!tank!and!basin!ensure!nonZworsening!is!achieved.!!
This! plan! demonstrates! that! effective! treatment! of! stormwater! generated! by! the!
proposed!development!can!be!achieved!through!the!integration!of!Water!Sensitive!
Urban!Design!(WSUD)!principles.!!Through!the!incorporation!of!bioretention!gardens!
and!detention!system,!the!plan!successfully!demonstrates:!
•     Compliance!with!the!requirements!of!NSC’s!Water!Quality!Objectives;!
•     Ecological!sustainability!in!terms!of!the!development’s!impact!upon!receiving!
      waters;!and!
•     Compliance!with!NSC!nonZworsening!of!peak!flows!in!the!2,!5,!10,!20,!50!and!
      100!year!ARI!storm!events!(Development!Condition!28a)!
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