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

The revised design rainfall patterns represent Duration        •   Major (100 year ARI); or




                         T
Independent Storm (DIS) patterns derived from Australian
                                                               •   Extreme (500 year ARI).




                       F
Rainfall and Runoff (AR&R) Intensity Frequency and




                     A
Duration (IFD) curves for this region.                         The Disaster Management Flood Map series cover all




                  DR
                                                               locations where Council possesses flood models and need
The SCC 2013 update also included the modifications            to be updated periodically to reflect changes within the
to cross section depths for the river bathymetry near to       catchments and upgrades to flood models.
the river mouth (as applied in the 1995 model) and the
inclusion of dynamic tailwater boundary conditions for         6.3 Online flood mapping resources
Laguna Bay.
                                                               Three forms of flood mapping can be accessed via Council’s
The dynamic tide boundary assumed the probability of the       website. These include:
river flood matched the probability of the storm tide with
the peak of the storm tide timed to coincide with the peak     •   River and Storm Tide flood map series prepared
of the rainfall.                                                   by Sunshine Coast Council and accessible via the
                                                                   Disaster and Emergencies and Get Ready web pages
The SCC 2013 model updates included model scenarios for            (http://www.noosa.qld.gov.au/river-and-storm-tide-
both existing and future climates.                                 flood-maps)

                                                               •   Noosa Plan’s Natural Hazard Landslide and Flooding
Future climate scenarios were used as the basis for the 2016
                                                                   Overlay series (OM1.3 to OM 9.3); and
amendment to the Planning Scheme flood hazard area.
                                                               •   Council’s online interactive mapping portal. The portal
The results of the SCC 2013 model updates also form the            currently presents three flood inundation layers:
basis of the current flood mapping and design event flood
                                                               1. Flood 100y Inundation Info – depicts the limit of
levels for the Noosa River.
                                                                  flood inundation mapping derived from related flood
                                                                  studies for a location.
6.2 2014 Disaster Management Flood
    Maps                                                       2. Flood 100y Inundation Area – depicts a flood
                                                                  inundation extent polygon (non transparent) for the
The 2014 Disaster Management Flood Map series are                 100 year (1% AEP) flood inundation based upon
based upon the flood inundation extents derived from the          current climate conditions and derived from the
SCC 2013 flood model updates. Flood inundation extents            Noosa River Flood Study, JWP 1995.
have been projected onto a digital elevation model of the
                                                               3. Proposed Flood Hazard Overlay 2014 – depicts the
ground surface derived from aerial laser survey.
                                                                  proposed amendment to the Planning Scheme as
Disaster management flood maps are based upon existing            advertised for public consultation. Public consultation
climate conditions.                                               ended in October 2015.

                                                               4. Final Flood Hazard Overlay 2016 Amendment
Each flood map series references the relative magnitude of
                                                                  (Pending Minister’s Approval).
the flood event as either:

•   Minor (2 year ARI);

•   Moderate (10 year ARI);




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