Original source · versioned page text
240913_360CC to NC_Lot 5 Majestic Dr_OPW IR Response
The Chief Executive Officer Noosa Council PO Box 141 Tewantin QLD 4565 Via email: - [email protected]@noosa.qld.gov.au Attention: - Mark Lewis 24 September 2024 Dear Mark, RE: OPW24/0114 - INFORMATION REQUEST RESPONSE for Lot 5 Majestic Dr, Pomona Application No: OPW24/0114 Proposal: Operational Works Street Address: Lot 5 Majestic Dr, Pomona Real Property Description: Lot 5 SP 324164 Planning Scheme: Noosa Plan 2020 (25 Sept 2020) This correspondence is in response to Council’s Information Request dated 5 August 2024. Please be advised that this response addresses all the items raised in Council’s Information Request. Information Request Item 1 – Issue: - The submitted plans do not include sufficient information about whether the reduced width of open drain at the rear of the property has the capacity to cater for the flow from the upstream catchment and if so, how the embankment is finished behind the proposed retaining wall. Information Request Item 1 – Information Required 1. Please demonstrate that the reduced width of open drain at the rear of the property functions and has the capacity to cater the flow from the upstream catchment. 2. Provide additional detail on how the area between the proposed retaining wall and the property boundary will be treated/controlled to ensure that erosion does not occur.
See the original
The page text is free to read. Viewing or downloading an original file needs an account.
Log in to see the originalFull text of the other 4 pages
Page 2
Information Request Item 1, Part 1– Response: -
A desktop study was completed to determine the impact. The information used to
determine the situation was:
1. The as-constructed survey of the original subdivision provided by Lands Surveying
Dynamics; and
2. Photo evidence of the batter for areas outside the property boundary and outside
the survey extent. Photos were provided by Axis Surveys.
An approximation of the upstream catchment has been calculated to determine the flow
rate for a 1% AEP event.
As per the image below, the upstream catchment has been calculated to be approximately
1200m2.
Figure 1 – Catchment calculations based on the as-constructed survey provided by Land
Surveying Dynamics
The Time of Concentration has been calculated as 15mins using Figure 4.4 from QUDM for
the first 100m of flow and Friend’s equation for the subsequent flow. The resulting time of
concentration is approximately 15mins. Using the Mannings equation, the 1% AEP flow rate
has been calculated to be approximately 0.065m3/s.
The channel has a longitudinal grade of approximately 7.5%. The slope of the batter on the
development side has been calculated as a 1:3 batter.
The slope on the non-development side has been calculated as a 1:6 batter based on the
image below which was taken by Axis Survey.
Page 3
Figure 2 – Image of the existing channel at the rear of Lot 5 Majestic Dr photo taken by Axis Survey Based on the above parameters and a Manning’s “n” of 0.03, the flow depth for a 1% AEP event is expected to be approximately 0.13m deep at the invert of the channel. At 0.13m deep, and a 1:3 batter, the water is expected to extend 0.39m into the property. The location of the retaining wall is located 1.4m in from the property boundary. As such the proposed retaining wall is not expected to have any impact on the proposed channel flow or the freeboard of the 1% AEP. The civil design for the original subdivision was completed by TOD Consulting and assessed and deemed compliant by Noosa Council. This letter has demonstrated that the proposed retaining wall will not impact the flow of water, and hence will not impact on the original assessment of the channel at the rear of the development. Information Request Item 1, Part 2 – Response: - As demonstrated by the response to information request item 1 part 1, stormwater flows are not impacted by the proposed retaining wall. As such, the proposed batter treatment has been designed by TOD Consulting and assessed and checked for compliance by Noosa Council. It is proposed that no changes to the batter surfaces be made as part of the proposed retaining wall for the land between the base of the retaining wall and the property boundary. Information Request Item 2 - Issue: - Removal of the existing crossover. The submitted plan mentions that the existing crossover is to be removed. Council has some concerns that the removal will impact on the ability to enter
Page 4
and exit the property opposite (Lot 6, No 8). Information Request Item 2 – Information Required: - Provide swept paths to demonstrate if the existing crossover can be removed without impacting on the access to the opposite property. Please note that if the existing access must be maintained that Council is unlikely to support its ongoing use to access Lot 5 (no 11). Information Request Item 2 – Response: - Please find attached the requested vehicle turning movement demonstrating that 8 Majestic Dr is not reliant on the existing crossover to 11 Majestic Dr, Pomona for entering or exiting movements. The attached vehicle turning movement demonstrates that the crossover to 11 Majestic Dr is not utilised to access 8 Majestic Dr. Based on this turning movement it is proposed that the removal of the existing crossover to 11 Majestic Dr will occur and that access to 11 Majestic Dr will be via the new proposed crossover detailed on 360CC drawing 03. This response to Item 2 of the Information Request has already been provided to Noosa Council along with the vehicle turning movement detailed on SK01 and Council have confirmed that this response is acceptable and that the existing crossover to Lot 5 can be removed. 360 Civil Consulting has provided all of the information requested in the Information Request and request that Council proceed with its assessment of the development application. Please do not hesitate to contact the undersigned on 0403 862 009 should Council require any further information in order to finalise this operational works application. Yours sincerely, Beatrice Gibberd Director and Principal Engineer 360 Civil Consulting Pty Ltd
Page 5
6.00m
6.00m
W
W
W
W
87.00
87.00
W
//
//
W
W
W
// W //
W
//
//
0 2 4 6 8 10m
SCALE 1:200 A3
Datum AHD Scale As Shown Status FOR APPROVAL
ABN: 13 609 593 339 Project Proposed Driveway Drawing Title Vehicle Turning Movement Plan
Date August 2024 Drawn JAG Checked BG PO Box 5028
NORTH
Maroochydore BC
© 360 Civil Consulting Pty Ltd - All Rights Reserved.
This drawing as been produced for the sole benefit of the Designed JAG Approved BG Location 11 Majestic Dr, Pomona
Client in accordance with the Terms of Agreement. QLD 4558
No responsibility or liability will be assumed to any third BEATRICE GIBBERD RPEQ 14557 Mobile: 0403 862 009
party. This document shall only be used for the site and
project specified.
Issue Date Description By Chkd
Email: [email protected] Client L. Thornton Project No. 2024038 Dwg No. SK01 of 01 Issue -