Narellan Creek Overland Flood Study (Vol 1) - Flipbook - Page 16
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DATA COLLECTION AND REVIEW
2.1
Overview
A range of data were made available to assist with the preparation of the detailed overland
flow study for the Narellan Creek catchment. This included previous reports, flood models,
digital data, and engineering plans.
A description of each dataset along with a synopsis of its relevance to the current study is
summarised below.
2.2
Previous Reports
2.2.1
Harrington Park Hydrologic and Hydraulic Report (2000)
The Harrington Park Hydrologic and Hydraulic Report was prepared by SMEC for Camden
City Council in 2000. The report was prepared to support the design on the Harrington Park
Lakes water quality and flood management system.
Hydrologic modelling was completed as part of the study using the XP-RAFTS software and
the hydraulic analysis was completed using the MIKE-11 software. No calibration was
completed for either model.
Much of the information contained in this report is now outdated, most notably the
considerable changes that have occurred across the upstream catchment since the models
were originally developed. Furthermore, the 1-dimensional hydraulic modelling software
used has largely been replaced with 2-dimensional hydraulic software. Therefore, this
report is considered to be of limited value to the current study, particularly with access to
more recent flood studies, as discussed below.
2.2.2
Narellan Creek Flood Study (2015)
The Narellan Creek Flood Study was prepared by Worley Parsons for Camden City Council in
2015. The primary goal of the flood study was to quantify existing flood behaviour across
the Narellan Creek catchment. The focus was on defining mainstream flood behaviour and
major overland flow paths rather than fine scale/shallow inundation.
The study included the development of an XP-RAFTS hydrologic model and a TUFLOW
hydraulic model to assist in defining flood behaviour across the catchment. The models
were calibrated against recorded flood marks as well as anecdotal flood information
provided by the community for floods that occurred in February 2007, February 2008, and
January 2013.
The calibrated models were used to simulate a range of design floods (i.e., from the 50%
AEP flood up to the probable maximum flood). All design floods adopted a 20% AEP Nepean
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