2016-07-18 General Committee Meeting - Item 3 - Attachment 1 - Flood Management Plan

Council provides online access to a series of River and           To provide correct advice during a flood event on the




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Storm Tide maps (in PDF format) for communicating                 current triggers and consequences requires each flood




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the progression of potential flood extents and the relative       gauge to be maintained and calibrated to transmit accurate




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depth of potential flooding within the inundation extents.        incremental signals. Also, once received by the Enviromon




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These maps are not linked to any identifiable triggers which      system, these signals then need to be translated into
might be used to inform disaster management activation            meaningful rainfall depths or water levels which can then
responses.                                                        be related to real world conditions. All gauges will require
                                                                  periodic maintenance to ensure they are functioning as
The organisation also possess a series of flood maps              expected. In addition to the maintenance of mechanical/
depicting flooding from a variety of flood trigger levels         digital infrastructure of each gauge the numerical
and covering all major waterways and at risk communities.         translations embedded into the Enviromon system should
These maps have been developed following a series of flood        also be periodically checked.
study upgrades undertaken by the Sunshine Coast Council
prior to de-amalgamation. These flood maps should be              Council has identified flood triggers for some telemetry
presented online.                                                 gauges to inform disaster management activation levels.
                                                                  These triggers currently correspond to the design event
10.1.2     Disaster management triggers                           flood levels anticipated at each telemetry gauge location for
                                                                  the 2 year (minor), 10 year (moderate), 100 year (Major)
Setting disaster management triggers is a two stage process.
                                                                  and 500 year (Extreme) average recurrence interval flood
The first stage being the correlation of the recorded (real-
                                                                  events.
time) water level (or rainfall intensity) for a gauge site with
an equivalent design flood event reference (i.e. Minor,           It is recommended that flood triggers to be set for all
Moderate, Major or Extreme). This reference enables the           telemetry gauges and that corresponding on-ground
magnitude of the event to be quantified and communicated          responses and impacts be identified for each trigger level.
effectively. The second stage is then to be able to communicate
the likely consequences to the community of each of the           10.1.3    Disaster management redundancy
design event levels. Consequences may include inundated
roads, inundated properties, isolated communities etc.            To effectively advise on flood related conditions during
The identification of possible/likely consequences from           a flood event requires access to readings or observations
each level of flood event can be informed by desktop              of current water levels and the ability to translate these
analysis and anecdotal advice received from individuals           readings into meaningful advice to other stakeholders.
in the community and stakeholders within Council and              Standard procedures for monitoring river/creek water
associated emergency services. Appropriate responses to           levels and catchment rainfall are dependent upon the
each of the consequences identified are the responsibility        functionality of each of the rainfall and river height gauges,
of each emergency services agency.                                the ability to receive signals from each gauge, the ability
                                                                  to translate these readings into meaningful references and
For efficiency of providing timely advice and                     the ability to communicate these references to a broader
communications during a flood event it is recommended             stakeholder group. To fulfil these standard procedures
that the flood triggers and associated consequences be            requires a number of critical systems to be functional.
determined prior to an event.




                                                                                       Noosa Council | Flood Management Plan | Page 34