2015-04-28 Planning and Organisation Committee Agenda

PLANNING & ORGANISATION COMMITTEE MEETING AGENDA                                  28 APRIL 2015


10    FLOOD DATA COLLECTION AND ANALYSIS FROM CYCLONE MARCIA
Author            Principal Strategic Planner, Rebecca Britton
                  Planning & Infrastructure Department

Index             ECM/Subject/Flood Management/Flood Studies

Attachments       1.   Cyclone Marcia Hydrologic Data Collection and Analysis


EXECUTIVE SUMMARY
Not applicable.

RECOMMENDATION
That Council note the report by the Principal Strategic Planning to the Planning &
Organisation Committee Meeting dated 28 April 2015 on flood data collection and analysis
as a result of Cyclone Marcia.


REPORT

The after-effects of flooding often provide the opportunity to collect data to help improve
Council’s understand of flooding characteristics in the Noosa Shire. Collection of flood level
data provides a useful historical reference of flood magnitude and frequency and is used for
future validating of flood modelling. The process involves measuring and collecting
observable peak flood levels in the field (from debris, water stains etc) and analysing the
rainfall intensity data recorded at the various rainfall gauges throughout the Noosa Shire.

Ex-tropical cyclone Marcia resulted in moderate precipitation throughout much of the Noosa
Shire with greater intensities in the hinterland areas. This caused minor to moderate flooding
in several areas, with Cooran being the most heavily affected.

The attached report documents that the Annual Exceedence Probability (AEP) peak average
intensities for the various localities in the hinterland were around the 5%AEP (1 in 20 year)
and 20%AEP (1 in 5 year).

This information has been recorded and incorporated into Noosa Council’s GIS layer which
contains data for all recordings associated with previous historic flood events. The data is
therefore readily available for future flood studies and Council flood searches.

Previous Council Consideration

Nil

Finance & Risk

Collection of flood data is seen as good practice for ensuring up to data flood level
information for managing flood risk through planning, development regulation and works
design and for increasing Council’s preparedness for future disasters.




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