Moreton Bay Regional Floodplain Database

Storm Tide Flooding

Version 2.1.0 (June 2015)

This theme shows potential flooding caused by abnormal increases in tide. Strong winds associated with a cyclone or intense low pressure weather system can push a raised mound of seawater, called a storm surge, onto the shoreline. This surge when combined with the astronomical tide and increased wave action is called a storm tide. Storm tide occurs in low-lying locations near the coast.

Methodology

Coastal (offshore) hydrodynamic modelling using a two-dimensional, curvilinear grid. A bathtub approach has been used to extrapolate the model results onto the landward side of the coastline. Refer technical publications available from Council's website for further detail.

Existing Conditions Cyclonic Scenario

Modelling a storm tide under existing climate conditions - cyclonic activity.

Purpose

To describe existing flood behaviour during a storm tide caused by cyclonic activity.

Methodology

Coastal (offshore) hydrodynamic modelling using a two-dimensional, curvilinear grid. For this scenario an increase in average wind speed of 10% is assumed. A bathtub approach has been used to extrapolate the model results onto the landward side of the coastline. Refer technical publications available from Council's website for further detail.

Flood Data Notes

Describes the expected reliability of the flood data including indication of specific areas where Council is of the opinion that the data has limited reliability and a reason for this limited reliability.

rfdRepresentationDescription

Modelled Probability

The probability of flooding represented by this dataset is:

0.1% Chance of Flooding in Any One Year

Likelihood: Unlikely

Annual Exceedance Probability (AEP): 0.1%

Average Recurrence Interval (ARI): 1,000 Year

A very large and very unlikely flood event. Over a very long period of time an event of similar size may occur on average once every 1,000 years. Few people will ever witness an event of this size. When an event of this size is observed it is considered to be very exceptional. A river and creek flood event of similar size occurred in the middle reaches of the North Pine River during January 2011. Whilst very unlikely, it is possible for these events to occur.

Version Notes

2.1.0 - TUFLOW modelling with a dynamic Storm Tide boundary (June 2015)

Version Resolution: 2.5m

Data Reliability: A

Indicates the flood data is of the highest available standard and has been prepared using the most recent flood model and input data

Further Information

For additional information on flooding in the Moreton Bay Region please see Council's website: http://www.moretonbay.qld.gov.au/floodcheck/