Response to Info_Request_stg6 REC14 0009 2-10-14 Callaghan Toth

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Council Riparian Buffer Area on revegetation plan 1225-89a. This additional
rehabilitation south of the mapped Riparian extent provides an offset area for other
areas of Council mapping that are not practical to re-vegetate.

e Rehabilitation Plans have been prepared detailing the weed control, planting and
maintenance requirements for these riparian areas that will be rehabilitated.

e Itis considered that the Riparian Buffer Area as mapped on OM 3.1 is schematic to
indicate areas to be assessed on the ground and determine areas to be protected.

e The riparian buffer provided adjacent to Lots 14, 15 and 16 includes all the existing
riparian vegetation along this watercourse, i.e there is no riparian vegetation in Lot 14,
15 and 16. Most of the site including these lots is grassed as a result of previous
clearing and farming.

e By providing generally 10m from top of bank and rehabilitating this area the
development retains the existing habitat, maintains the existing wildlife corridor,
maintains the stability of the watercourse, and will enhance its values by removing
weeds and planting native species where infill planting is required.

e As such it is considered that the Biodiversity Overlay has been complied with by
providing a setback of a suitable distance to protect the values of the watercourse
and riparian zone. And by rehabilitating this area the biodiversity values of this
watercourse will be enhanced.

e Therefore the boundaries to Lot 14, 15 and 16 will be changed as per plan 1225-89a.

3. Please provide a proposal plan with the Noosa Plan’s Biodiversity Overlay overlaid to
provide clarity

Response:

Please refer to revegetation plan 1225-89a which shows the Biodiversity Overlay Riparian
extent.

Engineering and Hydrology
4. Provide a Flood Report for the development.

Response:
Please refer to Brisbane Stormwater Management (BSM) Flood Report dated 15-9-14.

5. The lot layout may require amending subject to Councils acceptance or other revision
of the Stormwater Detention and Flood Report.

Response:

The Flood report has been recently revised to address Council concerns so allotment layout
should not need to change.

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6. Provide a preliminary engineering design for the necessary road works. The design
must be prepared by an RPEQ and extend from the existing formation in Cordwood
Drive the the full length of ‘Masonry Street’. The design must include:

Levels (natural surface and finished design)
Cross Sections and Longitudinal Section
All banks and batters

Stormwater

Existing services

Temporary Turnaround (if required)

~D9AOTD

Response:

Please refer to enclosed layout plans 1225-61a, 1225-62a, Longitudinal Section 1225-65a,
Cross sections 1225-66 to 1225-72 inclusive (revision a).

On enclosed plan 1225-80a we show existing water main, communications, and
underground electrical that is on the western side of Masonry Street. These services
currently terminate at the southern boundary of Lot 12 SP248255. There are also existing
sewer and water mains traversing the property in easements, see 1225-60a.

It is planned to complete stages 5 and 6 in one Construction Contract therefore a temporary
turnaround is not required.

7. Provide comment on the potential affects on the flood plain created by the proposed
roadworks. Please note that the Q100 line indicated on the plans is part of the
adjoining application and has not been accepted by Council at this time.

Response:

The proposed roadworks are nearly all above the Q100 flood line therefore flood plan effect
is considered negligible. A small part of proposed cul-de-sac fill batter is in the flood plain
however this has been accounted for in the Flood Study by BSM. Please refer to enclosed
plan 1225-61a and 1225-62a which shows developed Q100 extents.

Filling to lots 13-16 adjacent to floodplain has been completed using retaining walls to avoid
negative impacts from subdivision construction works. Refer to 1225-61a and 1225-62a for
details of retaining walls and flood line.

8. Provide a preliminary engineering design for the necessary stormwater drainage
works. The design must be prepared by an RPEQ and include:
a. Stormwater drainage from the roadworks and the proposed lots.
b. Stormwater drainage to service the adjoining Lot 1 RP173883 and any
structures necessary to address runoff from the adjoining properties.
c. Stormwater detention and treatment devices for the relevant stage.

Response:

a. Please refer to enclosed Plan 1225-61a and 1225-62a which show the stormwater
layout. There is interlot drainage to lots 13-16 which do not slope towards the road.

b. Lot 1 RP173883 has been provided with a stormwater and sewer connection. There
is not considered to be a need for structures to address stormwater runoff from
adjacent properties as lots on Cordwood Drive have interlot stormwater pits.

c. Stormwater detention is referred to in BSM report dated 15-9-14 in item 1 page 5.
The bridge and bund detention referred to in the BSM report is shown on attached

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plan 1225-92a and long/cross section plan 1225-94a.

The stormwater quality treatment device for stage 5 is a bio-retention basin, refer to
plans 1225-61a and 1225-62a. The stormwater quality calculations for this bio-
retention basin were previously provided Stormwater Quality Management Plan for
REC13/0146 information request with our letter dated 24-4-14.

This basin also has a detention component which is included in BSM flood report
dated 15-9-14 Figure 12.

9. Provide amended plans that indicate the easements necessary to cater for the
proposed lots, the adjoining properties and any existing services that traverse
through the site.

Response:

Please refer to response and amended Plans from Max Watterson and Associates.

Yours faithfully,
Callaghan & Tot!

LE Wei x

A Haynes BE Civil RPEQ (civil) MIEAust CPEng

    

Please view www.callaghanandtoth.com.au for all information on our company profile and terms and conditions for services rendered

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