ASTP-Rspns_To_RFI

With respect to Information Request Item 2, Ingeniir (Attachment 1) details that the lot is located on a slight
ridge between Opal Lane and Ruby Street, with the site discharging to both street frontages.

Ingeniir confirms that the proposed development provides a preferred drainage arrangement by providing direct
surface falls to Opal Lane, rather than the current arrangement of draining to Opal Lane through the
neighbouring property to the west.



            ITEM 3:
            Provide RPEQ written certification, certifying that the proposed Earthworks and Stormwater
            Management Plan will not cause a worsening of stormwater conditions by adversely altering
            stormwater drainage characteristics external to the site, including, but not limited to:
                     a) additional ponding on neighbouring properties or on road reserve;
                     b) increased runoff onto neighbouring properties or road reserve
                     c) redirect overland flows.

Response:
With respect to Information Request Item 3, the Information Request response prepared by Ingeniir
(Attachment 1) provides the following response to the following response:

     a.   The property does not currently receive runoff from the surrounding properties as the Eastern boundary
          is fenced with a sleeper at the base, which limits stormwater from the upstream allotments. As such the
          proposed retaining along the Eastern boundary will not impact the existing flow regimes on the site or
          neighbouring properties.

          By providing positive surface drainage in the rear of the lot to Opal Lane the development will have a
          beneficial impact on the neighbouring properties to the West.

     b.   The existing impervious area in the rear portion of the allotment (fronting Opal Lane) is comprised of 2
          sheds and paved landscaping around the pool area totaling 170m2. The proposed roof area of the new
          building is 160m2 hence is less than the existing impervious area to be removed as part of the
          development, as such will be non-worsening for stormwater runoff.

     c.   The development only proposes to redirect surface flows on the rear portion of the allotment to avoid
          draining to Opal Lane through the neighbouring property to the West; and will drain to Opal Lane
          directly as a result which is considered a beneficial outcome.



            ITEM 4:
            Alternatively, provide an updated Stormwater Management Plan for the site, including,
            but not limited to:
                   4.1details of any required stormwater pipelines/flowpaths within the site to drain low
                       areas on all adjoining properties to prevent additional stormwater ponding;
                   4.2 details of any required structures to collect and convey existing overland flows that are
                       impacted on by the construction of the proposed retaining walls.




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