Z40770_Response to InformationRequest_NC_final

1 November 2016
SCG Ref: 26232(L1)

By email: [email protected]


Att: Stephen Vlatko-Rulo
Raftsea P/L
C/- Downes Survey Group Pty Ltd
PO Box 39
NAMBOUR QLD 4560


Dear Sir

     Re: Proposed Development – Lot 4 (#85) Rene Street, Noosaville, (Council Ref: OPW16/0209)

As the Civil, Structural and Geotechnical Engineers for the above project we confirm we have reviewed
Council’s recent request for information dated 20 October 2016.

We comment regarding Council’s issues as follows: -

Issue 1

      a) The bio-retention basin(s) have been sized in accordance with the ‘Deemed to Comply Solutions –
         Stormwater Quality (South East Queensland)’, by Water by Design. The deemed to comply solution
         for commercial/industrial development without new road, site area less than 12500m 2 has been used
         with a minimum bio-retention filter media area of 2.2%.

           In addition, we have specified the use of vegetated swales to convey stormwater within the site and
           the inclusion of a water storage tank for use of captured stormwater. These measures further
           increase the level of stormwater treatment beyond the ‘deemed to comply’ minimum requirement.

      b) We have revised our plan SCG 26232-SW1 to include pipe invert levels (copy attached).

      c) We have specified a minimum filter depth of 600mm which satisfies the Water by Design
         requirements of 400-1000mm. We have nominated a ponding depth of 200mm within the bio-
         retention bed to be formed by timber sleepers. This information is presented in the Bio-retention Pit
         Detail shown on our plan SCG 26232-SW1.

      d) We have conducted soil testing on the site for our structural design. Results confirm that the fill depth
         ranges from 1.0m-1.2m in the areas tested. Excavation for the bio-retention beds will not extend
         beyond this depth. We have included a copy of soils report for the site which confirms this
         information.