Response to Information Request Letter 10-6-2025 · OPW25/0042

Such velocities are less than maximums suggested in QUDM table 9.05.3 for easily eroded soils
with 50% coverage and less than maximums recommended for vegetated channels in QUDM
table 9.05.1

The Ephemeral Stream area will enjoy interaction with hotel guests and will be regularly
maintained by hotel groundkeepers such that any damage after an overland flow event would be
promptly rectified.

ALTA notes that the stream analysis is conservative and completely ignores infiltration afforded by
RIPs located on existing external catchment sites.

Issue – Extent of Vegetation in Overland Flow Channel
The higher order development plans suggest that the trapezoidal channel will include
landscaping (beyond turf) in the Overland Flow Channel. This is Council’s preferred outcome.
However, the inclusion of vegetation within this channel is inconsistent with the current
hydraulic design assumptions and could lead to flow breaking out of the channel and cause
flooding.

Information Required
8.    Confirm the Overland Flow Channel will be vegetated to achieve a natural channel
design and meet the required hydraulic design assumptions.

Response
ALTA has relied on the above response regarding hydraulic performance and suggest it
demonstrates that a grassed or vegetated channel with 1:2 batters would provide adequate
performance and stability.

Which channel landscape treatment is adopted is subject to a future landscape OPW application to
determine.

Item – Construction Traffic
A Traffic Impact Assessment has not been provided as part of the application material.
Council recognise that the haulage operations are likely to cause impacts to the local road
network and associated road infrastructure.

Information Required
9.    Provide a Traffic Impact Assessment (TIA) to assess the impacts of construction traffic
      associated with the prescribed works. The TIA must be prepared by a suitably qualified
      person (RPEQ) with Traffic Management Design qualification, in accordance with the
      Department of Transport and Main Roads Guidelines, and must include, but not be
      limited to:
        a. a Road Safety Audit;
        b. Pavement Impact Assessment;
        c. a Traffic Management Plan – the Traffic Management Plan must be developed in
            accordance with the Queensland Manual of Uniform Traffic Control Devices
            (MUTCD) and the Queensland Guide to Temporary Traffic Management (GTTM);