2021-10-08 SM - Item 1 - Attachment 2 - Draft Coastal Hazards Adaptation Plan - tracked changes

NOOSAVILLE
Setting
The Noosaville locality is a vibrant urban setting defined by watercourses and bushland edges
including the Noosa River, Eenie Creek, Lake Weyba, and Noosa National Park. Noosaville
provides much of the commercial, retail, administrative, industrial and social needs of the coastal
urban portion of Noosa Shire and is a major focus area for visitor accommodation and services.
The Noosa River foreshore adjacent to Gympie Terrace is an important recreational space for the
local community and visitors. The area is popular for passive recreation, walking, dog exercise and
access to the Noosa River including ferry stops.

Noosaville is topographically quite flat with much of the locality having an elevation of only a few
meters above present-day high tide levels. For this reason, low-lying parts of Noosaville already
see inundation at king tides, and “daylight flooding” (due to overflowing stormwater systems) after
heavy rainfall events.

Risks to Noosaville
Significant areas of Noosaville adjacent to the Noosa River and other waters is considered at high
to very high risk from tidal inundation by the end of the planning period. The low topography of the
locality means many assets are likely to be exposed to frequent inundation. The most prominent of
these are publicly owned assets, namely foreshore recreation areas, the road network (including
footpaths) and the gravity-based stormwater network. Some residential lots are projected to be
partially inundated, though this is unlikely to include the dwellings themselves, only gardens and
driveway areas. A small number of tourism and commercial operations may also be affected by
inundation. Environmental values present across natural foreshore areas of the river20 and the
conservation parks will be affected.

Appendix 34 shows the change in risk profile across various parts of Noosaville as the area
exposed to the effects of periodic tidal inundation increases over time. Table 18 provides a
summary of the changing risk profile for six broad asset types within the locality that are projected
to be exposed to the effects of periodic tidal inundation between present day and 2100.

The most significant concerns in this locality relate to the risks to foreshore parks, given the
reliance of locals, visitors and adjacent businesses alike on them to create safe and attractive
places to spend time. Some areas of Quota and Apex Parks are can almost certainty expect to be
inundated under normal tidal conditions to depths of 10cm for at least 1 hr per day for up to 300
days per years. The exposure of Council-managed infrastructure, in particular the stormwater
network, is of significant concern as this network already affected by intrusion of saline tidal waters
onto the stormwater pipes. As sea levels increase, this is expected to occur on a daily basis.

This salt water intrusion presents two key problems. Firstly, the salt water may damage assets that
are not expected to be regularly exposed to salt water and these waters may lead to sedimentation
of the network. Secondly, the network is designed to carry a specified volume of overland flows of
water during rainfall away from developed areas and into the Noosa River. If the network capacity
is taken up by tidal waters, these overland flows cannot enter the network and flow out the river,
thus potentially leading to some increased flooding in the road network during minor rainfall events.
From mid-century onwards, it is very likely that tidal waters may flow back up the network and into
the street even under sunny day conditions. As a result, both of these scenarios may create
nuisance and disruption to the community, health and safety risks to residents and visitors, as well
as possibly leading to minor damage to public and private assets.




20 Including Keyser Island, Hay Island, and Ross Island.


Noosa Council – Coastal Hazards Adaptation Plan 2020 - 2030                                    Page 60