Engineering Report · MCU18/0094

       The subject site represents a very small percentage of the Cooroy Creek
       catchment conveyed by Garnet Street. The proposed development will
       create an inconsequential increased discharge into Cooroy Creek of 1.3%
       for a Q100 event and 1.37% for a Q10.

       Existing infrastructure is adequate to convey additional discharge from
       the proposed development via Garnett Street. Hence formal on-site
       attenuation of stormwater is not proposed.


       6.3     Stormwater Quality Management

       The subject site is below the 2,500m2 threshold which triggers the need for
       compliance with water quality objectives as outlined in the State Planning
       Policy guidelines (Dec 2013) and hence formal on-site treatment of runoff
       is not proposed.




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A6265 -18- Engineering Report – Garnet Street, Cooroy                       Page 5 of 4
Mar 2018    SH/tk
                                      Alta Projects P/L