240913_360CC to NC_Lot 5 Majestic Dr_OPW IR Response

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