Albert River Catchment Hydraulic Study · 2019. 6. 23. · TRACKS-#50669992-v2-ALBERT_RIVER_CATCHMENT_HYDRAULIC_STUDY_2015.docx Page 8 of 36 3. Background 3.1 Catchment Description

Albert River Catchment

Hydraulic Study July 2015

TRACKS-#50669992-v2-ALBERT_RIVER_CATCHMENT_HYDRAULIC_STUDY_2015.docx Page 2 of 36

Title: Albert River Catchment Hydraulic Study

Author:

Study for: City Planning Branch

Planning and Environment Directorate

The City of Gold Coast

File Reference: WF15/44/02(P6)

TRACKS #50669992

Version history

Version Comments/Change Changed by &

date Reviewed by &

date

1.0 Draft

2.0 Grammar Review

Distribution list

Name Title Directorate Branch


1. Executive Summary

In 2014, the Natural Hazards Team of the City Planning Branch undertook a hydraulic of all the

catchments within the Gold Coast area. The main purpose of these studies was to generate

Designated Flood Levels (DFLs) for the upcoming planning scheme which is scheduled for

release in 2015. This report documents the development, calibration and design event

simulations of the Albert River catchment hydrodynamic model.

The Albert River catchment is one of major catchments in the Gold Coast. It is a major tributary of

Logan River, with a catchment area of approximately 781 km2 up to Stanmore Road, Luscombe.

The Albert River headwaters rise in the mountains of the Lamington National Park and

discharges into the Logan River at Alberton. The Albert River is mostly narrow and shallow in the

upper regions of the catchment, and becomes wider and deeper closer to the Logan River

confluence. The lower reaches of the Albert River are tidally affected.

A hydraulic model of the Albert River catchment has been developed using DHI’s MIKE 11

software. The model is developed using the latest available data sets, standards and engineering

practices. The model was calibrated to January 1974, January 2008, January 2012 and January

2013 historical flood events. The recorded water level at Wolffdene gauging station was only

available data for model calibration for these flood events. A good calibration has been achieved

for the January 1974 and January 2013 flood events. The calibration for the flood events January

2008 and January 2012 were reasonable.

The calibrated model was then used to setup and simulate the design flood events for a range of

flood events. The hydrological input of this study was sourced from Logan River Catchment

Hydrological Study Addendum 2015. The tailwater boundary for the design events are based on

the Semidiurnal Tidal Planes 2014 and the Gold Coast City Council - Storm Tide Study, February

2013. An Arc GIS tool developed by Council officer was used to generate flood surfaces from the

MIKE 11 model results.


Table of Contents 1. Executive Summary ...................................................................................................................... 3

2. Introduction ................................................................................................................................... 6

2.1 Overview .............................................................................................................................. 6

2.2 Limitation Statement ............................................................................................................ 6

General ....................................................................................................................... 6 2.2.1

Hydraulic Model .......................................................................................................... 6 2.2.2

2.3 Acknowledgement ............................................................................................................... 7

3. Background ................................................................................................................................... 8

3.1 Catchment Description ........................................................................................................ 8

3.2 Previous Studies .................................................................................................................. 9

Albert River Hydraulic Study (City 2014a) .................................................................. 9 3.2.1

Logan River Catchment Hydrological Study Addendum (City 2015a) ........................ 9 3.2.2

Logan River (Woongoolba) Catchment Hydraulic Study (City 2015b) ....................... 9 3.2.3

Logan River Catchment Hydrological Study (City 2014b) .......................................... 9 3.2.4

Logan River Catchment Hydraulic Study (GCCC 2012) ............................................. 9 3.2.5

Logan River Flood Study–Hydrological Modelling (WRM 2009) ................................ 9 3.2.6

Logan River Catchment Hydraulic Study (GCCC 2007) ........................................... 10 3.2.7

Logan and Albert Rivers Mike 11 Flood Warning Model (PB 2004) ......................... 10 3.2.8

Logan and Albert Rivers Flood Plain Modelling Study (AWE 1997) ......................... 10 3.2.9

4. Hydraulic Model Development ................................................................................................... 11

4.1 Hydraulic Modelling Approach ........................................................................................... 11

4.2 Datum ................................................................................................................................ 11

Horizontal Datum ...................................................................................................... 11 4.2.1

Vertical Datum .......................................................................................................... 11 4.2.2

4.3 Available Data .................................................................................................................... 12

Bathymetric and Cross Section Survey .................................................................... 12 4.3.1

Structure Survey ....................................................................................................... 13 4.3.2

Gauging Station ........................................................................................................ 13 4.3.3

Reconnaissance Survey ........................................................................................... 14 4.3.4

Maximum Height Gauges and Debris Mark Survey Data ......................................... 14 4.3.5

Digital Terrain Model (DTM) ..................................................................................... 14 4.3.6

4.4 Model Extent ...................................................................................................................... 15

4.5 Model Network ................................................................................................................... 15

4.6 Hydrological Input .............................................................................................................. 15

4.7 Boundaries ......................................................................................................................... 15

4.8 Tailwater ............................................................................................................................ 16

4.9 Model Parameters ............................................................................................................. 16

4.10 Hydraulic Structures .......................................................................................................... 17

5. Model Calibration ........................................................................................................................ 18


5.1 January 1974 Calibration ................................................................................................... 18




6. Design Events .............................................................................................................................. 23

6.1 Introduction ........................................................................................................................ 23

6.2 Design Event Setup ........................................................................................................... 23

7. Mapping ........................................................................................................................................ 24

8. Conclusion ................................................................................................................................... 25

9. References ................................................................................................................................... 26

10. Appendices .................................................................................................................................. 27

Appendix A - Semidiurnal Tidal Plans ......................................................................................... 27

Appendix B – Hydrological Inputs and Sub Areas ...................................................................... 28

Appendix B1 - Hydrologic Output and Hydraulic Input Location ........................................ 28

Appendix B2 - Logan River Hydrologic Catchment and Subareas .................................... 28

Appendix C: Structures Photo ..................................................................................................... 29

Appendix D: Arc GIS Mapping Tool Interface ............................................................................. 34


2. Introduction

2.1 Overview

The Natural Hazards Team of the City Planning Branch undertook a hydraulic study for the Albert River catchment to develop the City of Gold Coast’s (City’s) designated flood level (DFL) for the City Plan 2015. A hydraulic model in MIKE 11 modelling software was developed and calibrated in this study. This study utilized the model from the City 2014a (Ref 1) with the following updates/modifications:

The low flow pipes under Stanmore Causeway have been included in the model.

The Chardon Bridge has been modelled.

The model has been recalibrated.

The hydrological input in the model is sourced from the Logan River Catchment Hydrological Addendum, 2015 (Ref 2).

Cross sections were enlarged based on DTM where deemed necessary.

Elevations of structures and cross sections have been extended high enough to exceed the maximum anticipated water level. The extensions were based on survey and DTM data.

This report documents available data, calibration, design events simulation and results from this study.

2.2 Limitation Statement

The limitations are discussed below:

General 2.2.1

The hydraulic report was prepared based on available information at the time of model development.

The analysis and overall approach adopted in this study is specifically prepared for internal use. For this reason, any third parties not authorised to use any contents from this report are prohibited unless a written approval from the City is obtained.

The City believes the assessment is accurate for its intended purpose and disclaims any responsibility for any loss or damage suffered as a result of placing reliance upon information provided in this report.

Hydraulic Model 2.2.2

The hydraulic model does not include stormwater drainage system (e.g. manhole, pipe, inlet pits, etc.) which may influence local flooding path and inundation extent. The City has a separate overland flow path hydraulic model to determine the local or flush flooding characteristics of the catchment.

The MIKE 11 Bridge modelling is based on the simplistic Energy Equation.


2.3 Acknowledgement

The City would like to acknowledge Bureau of Meteorology (BOM) and Maritime Safety Queensland for providing invaluable calibration data for this project.


3. Background

3.1 Catchment Description

The Albert River catchment is one of the major catchments in the Gold Coast. It is a major tributary of Logan River with a catchment area of approximately 781 km2 up to Stanmore Road, Luscombe. The Albert River headwaters rise in the mountains of Lamington National Park and discharges into Logan River at Alberton.

The Albert catchment is generally linear and includes three significant tributaries, Cainbable Creek, Canungra Creek and Cedar Creek. The Albert River is mostly narrow and shallow in the upper regions of the catchment, and becomes wider and deeper closer to the Logan River confluence. The lower reaches of the Albert River are tidally affected. Figure 1 below shows the locality map including the hydraulic model extent.

Figure 1: Albert River catchment within the MIKE 11 model extent,


3.2 Previous Studies

A number of hydraulic and hydrologic studies have been carried out for the Logan-Albert River catchment in the past. Brief descriptions of the most relevant studies are presented below:

Albert River Hydraulic Study (City 2014a) 3.2.1

A hydraulic model in MIKE 11 was developed in this study. The model was calibrated to January 1974, January 2008, January 2012 and January 2013 flood events. Finally the model was setup for the 1 in 100 year Average Recurrence Interval (ARI) flood for the storm durations 9, 24 and 72 hour.

Logan River Catchment Hydrological Study Addendum (City 2015a) 3.2.2

In July 2015, the 2014 calibrated Logan hydrological model (Ref 3) was used to run for a range of design events from 2 to 2000 year ARI’s using rainfall obtained from the BOM’s new IFD 2013 tables. The model estimated design discharges were compared with the design peak discharges obtained from the Flood Frequency Analysis (FFA) and original 2014 study. Monte Carlo simulation was undertaken to verify design discharges obtained from the URBS model. The model was also used to simulate Probable Maximum Precipitation Design Flood (PMPDF) and Probable Maximum Flood (PMF) with the rainfall losses obtained from the study.

Logan River (Woongoolba) Catchment Hydraulic Study (City 2015b) 3.2.3

The City developed a MIKE Flood hydraulic model in this study. The model starts from Stanmore Road, Luscombe to the South Moreton Bay. The model was calibrated to January 1974, January 2008, January 20012 and January 2015 flood events. The calibrated model was then used to setup for design and storm surge flood scenarios for a range of ARIs.

Logan River Catchment Hydrological Study (City 2014b) 3.2.4

In 2014, the City undertook a hydrological study for the Logan River catchment to review the WRM (2009) hydrological model. A hydrological model in URBS software was developed and calibrated to January 1974, April 1990, February 1991, January 2008 and January 2013 floods and verified against May 1980, April 1988, March 2004 and January 2012 historical flood events in the study. The calibrated model was used to estimate design flood discharges for 2 to 2000 year ARI, PMPDF and PMF for storm durations of up to 120 hours.

Logan River Catchment Hydraulic Study (GCCC 2012) 3.2.5

A hydraulic model for the Logan River catchment was developed through MIKE Flood software in this study. The model extent starts from Stanmore Road, Luscombe, and extends to South Moreton Bay. The model grid was sourced from the airborne laser survey, photogrammetric and bathymetric survey undertaken in different years. The model was calibrated to historical flood events against available data. The calibrated model was then used to simulate for a range of storm duration for different ARIs for flooding and storm surge scenarios and for the present (2010), 2050, 2070 and 2100 planning horizons and Probable Maximum Flood (PMF).

Logan River Flood Study–Hydrological Modelling (WRM 2009) 3.2.6

The City commissioned WRM Water and Environment to undertake a hydrological study for the Logan-Albert River catchment. In the study, a hydrological model was developed in URBS software and calibrated to available historical flood events (April 1990, February 1991 and January 2008), and verified against January 1974, May 1980 and April 1988 historical flood events. A Flood frequency analysis was also undertaken with available data at different gauging stations within the catchment. The calibrated model was used to estimate design flood discharges for 2 to 2000 year ARI and PMF for up to 120 hour storm durations.


Logan River Catchment Hydraulic Study (GCCC 2007) 3.2.7

A hydraulic model of the Logan River catchment was developed using MIKE Flood software. A 40 m resolution grid was used in the study. The model was calibrated to observed maximum water levels for the 1974 flood. Two sensitivity analyses were carried out by increasing and decreasing resistance by 20% compared to calibration. The calibrated model was used to simulate design flood events with 2 to 500 years ARI and storm durations ranging from 1 to 72 hours.

Logan and Albert Rivers Mike 11 Flood Warning Model (PB 2004) 3.2.8

The City commissioned Parsons Brinckerhoff to develop a MIKE11 model of the Logan and Albert River flood plain system for the purpose of real time flood forecasting and mapping of this area. The model was set up to allow forecast inflow hydrographs, generated by the BOM’s URBS model. This model was calibrated against January 1974 flood event and then was validated against 1976, 1991 and 1996 flood events.

Logan and Albert Rivers Flood Plain Modelling Study (AWE 1997) 3.2.9

In December 1997, the Australian Water Engineering (AWE) undertook a floodplain modelling study of the Logan and Albert Rivers for the Southern Region of Councils (comprising Logan City Council, Gold Coast City Council, Beaudesert Shire Council and Redland Shire Council). Hydrological and hydraulic models were developed in this study.

The hydrological modelling for this study was undertaken using the RAFTS model. This study updated two earlier studies undertaken using the RORB model in 1992 and 1994 for the Logan City Council by the same consultant. The RAFTS model was calibrated against the January 1974 and April 1990 flood events, and verified against the February 1976 and February 1991 flood events, at three gauging stations (Yarrahappini on the Logan River, and Bromfleet and Wolffdene on the Albert River). The calibrated model was then used to estimate 10, 20, 50 and 100 year ARI design discharges as inflows into a hydraulic model (2007) of the lower Logan-Albert River system.

The hydraulic modelling in this study was undertaken using EXTRAN software. This study was updated and combined two earlier studies undertaken using the WILCELL hydraulic models in 1992 and 1994 for the Logan region by the same consultants. The model was calibrated to recorded water level data of 1974 and 1990 flood events. The calibrated model was then used to simulate design flood for 10, 20, 50 and 100 year Average recurrence Interval. The City’s current designated flood level is based on this study.


4. Hydraulic Model Development

4.1 Hydraulic Modelling Approach

The Albert River catchment hydraulic model is developed using the MIKE 11 software (Version 2014, Service Pack 4). The MIKE 11 hydrodynamic module uses an implicit, finite difference scheme for the computation of unsteady flows in rivers and estuaries. The module can describe sub-critical as well as supercritical flow conditions through a numerical scheme that adapts according to the local flow conditions (in time and space). Advanced computational methods are included for description of hydraulic structures (weirs and culverts). MIKE 11 can be applied to looped networks and quasi two-dimensional flow simulation on floodplains. The computational scheme is applicable for vertically homogeneous flow conditions extending from steep river flows to tidal influenced estuaries.

Local storm water drainage networks, i.e. the pipes, inlet pits, manholes and outlets are not included in this model as they have a relatively small impact on the regional flooding characteristics.

4.2 Datum

Figure 2: Map Grid of Australia

Horizontal Datum 4.2.1

All horizontal coordinates that are used in this report are in Map Grid of Australia (MGA) Zone 56.

Vertical Datum 4.2.2

The vertical coordinates are referenced to Australian Height Datum (AHD) 1992.


4.3 Available Data

The following data were available for this study:

Bathymetric and Cross Section Survey 4.3.1

There are two bathymetric and cross sectional survey campaigns that have been undertaken within the Albert River catchment (Figure 3). These are:

Survey for Albert River from downstream of Stanmore Road, Luscombe, to confluence of Logan River was conducted in 2006.

The City Planning Directorate commissioned a consultant in 2014 to undertake cross sectional survey including major structures within the model extent. A total of 200 cross sections approximately at an interval of 100 metres were surveyed in September 2014 for Albert River and Cedar Creek. A structural survey for all the bridges, culverts, weirs and causeways along the surveyed section were also undertaken (section 4.3.2 ).

Figure 3: Structure and cross section Survey


Structure Survey 4.3.2

A structural survey has been undertaken in September 2014 for all structures within the study area along with cross sectional bathymetric survey (section 4.3.1 ). The structural survey included:

Six bridges were surveyed to include the structures dimensions (width/diameter, length), top level - road, bottom of deck level, a cross section immediately upstream/ downstream and centre of bridge, upstream and downstream invert levels;

One weir and one causeway to include a cross section immediately upstream/downstream and centreline of the structure, top level and dimensions of spillway.

Figure 3 shows all the structures surveyed in 2014.

Gauging Station 4.3.3

The Wolffdene Alert station is located within the study area. The gauging station has been operated by BOM since 1969. The station was malfunctioned during the flood event of January 2013.

Figure 4: Alert Station and maximum height gauges


Reconnaissance Survey 4.3.4

A site inspection was undertaken in August 2014 for all the major structures (Figure 3) in the study area. Photographs for structures were taken during the filed visit (Appendix C: Structures Photo).

Maximum Height Gauges and Debris Mark Survey Data 4.3.5

Two Maximum Height Gauges (MHGs) are available within the study area without any flood data for any flood event (Figure 3). The MHG 714, which is located just upstream of Stanmore Road causeway, was overtopped during the January 2008 flood event. In 2011, the gauge was reinstalled at a higher location to catch up future flood level. No debris mark survey data was available for this study.

Digital Terrain Model (DTM) 4.3.6

The City develops and maintains a DTM for the city using Airborne Laser Survey (ALS) and surveyed information. The DTM of the study area within the City was based on ALS 2009 and bathymetric survey undertaken in 2006. The ALS of the western side of the Albert River was obtained from Logan City Council where the survey was undertaken in 2013.

Figure 5: DTM data sources


4.4 Model Extent

The hydrodynamic model is extended from Tamborine to downstream of Stanmore Road, Luscombe (Figure 1). The upper extent of Cedar Creek was identified based on available data and field inspection conducted in August 2014 (Section 4.3.4 ). The upstream of the model extent (at Rowe Lane) of the creek was found to be very narrow and without any definite channel (refer Photo 8 and Photo 9 of Appendix C: Structures Photo). Catchment Areas downstream of Stanmore Road are covered by the Logan Hydraulic Study 2015 (Ref 4).

4.5 Model Network

The Albert MIKE 11 hydraulic model has two branches (Figure 6): Albert River and Cedar Creek. The length of the Albert River and Cedar Creek branches are 12.683 km and 5.235 km respectively. The cross sections were Included at an interval of less than 100 metres along the branches. The cross section data of the study is based on bathymetric and cross section surveys undertaken in 2006 and 2014 (Section 4.3.1 ). The Council’s DTM (Section 4.3.6 ) was supplemented to survey data where cross sections were required to extend beyond the banks of surveyed sections.

4.6 Hydrological Input

The hydrological inputs of this study are sourced from the Logan River Hydrological Study Addendum (Ref 2). The Logan River hydrological study included the Albert River, Logan River and Teviot Brook catchments.

4.7 Boundaries

Figure 6 shows the Albert MIKE 11 boundaries. The hydrodynamic model has three open boundaries. Two of them are assigned at the upstream end of the Albert River (Sc443_TH) and Cedar Creek (Sc446_TH). These boundaries are sourced from the Logan Hydrological Study Addendum 2015. The tailwater boundary is assigned at the downstream end of the Albert River branch (Section 4.8 ).

The four inflows assigned as point or distributed sources to the hydrodynamic model are also based on the Logan Hydrological Study Addendum 2015 (Figure 6). Appendix B shows locations and details of inflow hydrographs and Logan hydrological sub catchment delineation.


Figure 6: Model extent, MIKE 11 boundaries

4.8 Tailwater

The tailwater of this study was extracted from the Logan River Hydraulic Study 2015 (Ref 2). The Logan hydraulic model’s hydrological inputs were sourced from the same hydrological model as this study (section 4.6 ), and the tailwater was sourced from the GHD study 2013 and Marine Safety Queensland’s (MSQ) semidiurnal tidal planes (Appendix A - Semidiurnal Tidal Plans).

4.9 Model Parameters

Hydrodynamic parameters for the models are important to control model initialisation and model stability. The defaults values were kept standard except for Delta. The Delta value was modified from 0.5 to 0.75 to promote stability. The key calibration parameter for the hydraulic model is the channel roughness or Manning’s n roughness coefficient. In this study, Manning’s roughness


value 0.045 was adopted for Cedar Creek. Manning’s roughness values 0.045 and 0.03 were assigned at upstream and downstream respectively for Albert River.

The Initial water level of the model was set to 0.5 m AHD.

4.10 Hydraulic Structures

The City Planning Directorate commissioned a consultant in 2014 to undertake a survey of major structures within the model extent (Section 4.3.2 ). The survey included structure sizes, lengths, upstream and downstream invert levels, upstream and downstream cross sections and crowns of roads. All those surveyed structures were included in the MIKE 11 model for simulating flow constriction. The data for low flow pipe culverts under Stanmore Road causeway (Figure 7) were based on Council’s GIS database. The simplistic energy equation calculation method was chosen for all bridges with submerged, overflow and piers options. The MIKE 11 weir option was used for any overflow on top of bridges. The weir was chosen because the energy equation option for bridge overflow was not working, and the flow over bridges was constrained leading to water accumulating upstream of the bridges and generating unrealistically high affluxes.

Figure 7: Luscombe causeway


5. Model Calibration

5.1 January 1974 Calibration

A severe flood occurred during the January 1974 flood event in the Logan-Albert River Catchment along with other areas within the Gold Coast. Data is available only for the Wolffdene Alert station for the study for this flood event. This is the worse flood event on record in the area.

Figure 8 shows recorded and modelled flood levels at the Wolffdene Alert station for the January 1974 flood event. This calibration plot shows a good agreement between the modelled and recorded water level in terms of flood peak, timing and shape of the hydrograph.

Figure 8: Calibration plot, Wolffdene Alert, January 1974

Figure 9 shows the recorded and modelled discharges at the Wolffdene Alert station for the January 1974 event. As it can be seen from the figure, a good agreement has been achieved between the modelled and recorded discharge hydrographs.


Figure 9: Modelled and recorded discharges @ Wolffdene Alert, January 1974


The recorded data for the January 2008 flood event is only available at the Wolffdene Alert station. Figure 10 shows the modelled and recorded water levels at the gauging station. The calibration plot shows that the hydrograph shape is reasonable; however, the model did not perform well in terms of peak and timing. This is because of poor rainfall representation in hydrology (Figure 11) for this flood event.



Figure 11: Modelled and recorded discharges at Wolffdene Alert, January 2008


The recorded water level data at Wolffdene Alert station is available for the January 2012 flood event. The calibration plot (Figure 12) shows a reasonable hydrograph shape and perfect match from the water levels 0.5 to 3.0 m AHD. However the model result is not as good for the rest of the hydrograph. This is probably due to:

The recorded data is erroneous at the start and above 3 m AHD of the rising limb of hydrograph. The reason behind this assumption is that the water level of recorded data suddenly dropped after 24 January 2012 at 1 PM.

Poor rainfall representation in hydrology for this event (Figure 13).



Figure 13: Modelled and Recorded Discharge at Wolffdene Alert, January 2012



A very intense rainfall, caused by Ex-Tropical Cyclone Oswald, fell in the upper reaches of the Logan River catchment along with other areas of the Gold Coast. The rainfall caused minor flooding in and around the Logan River catchment. The Wolffdene Alert station malfunctioned during the January 2013 flood event (Figure 14). However few manual readings were available from BOM for the model calibration. The calibration plot shows a good match of peak values. However the timing of model peak did not match because of poor rainfall representation in hydrology or an error in recorded data.



6. Design Events

6.1 Introduction

Design floods are hypothetical statistical floods used for flood planning and designing of structures. They are based on a probability of occurrence, either as:

ARI – Average Recurrence Interval; or

AEP – Annual Exceedance Probability.

For example, a 100 year ARI or 0.1 AEP flood has an average recurrence interval of 100 years, or, the flood has a 1% probability of being equalled or exceeded in any one year.

With ARI expressed in years, the relationship is:

The different design events and corresponding AEPs are shown in Table 1.

Table 1 - ARI and AEP design floods

ARI (in Years)

AEP (as Percentage)

2 39.3%

5 18.1%

10 9.5%

20 4.9%

50 2.0%

100 1.0%

200 0.5%

500 0.2%

1000 0.1%

2000 0.05%

6.2 Design Event Setup

The calibrated Albert River MIKE11 hydrodynamic model was used to simulate a range of design flood events including 100 year ARI. The design simulation includes storm durations of 9, 12, 18, 24, 36, 48 and 72 hours. The hydrology of these simulations is sourced from the Logan River Catchment Hydrological Addendum 2015 (Ref 2). The sources of tailwater are discussed in section 4.8 .

The City’s Designated Flood Level for City Plan 2015 for the Albert River catchment is being developed using this model


7. Mapping

The results of MIKE 11 are a series of points located along the water course that have water level (m AHD), x and y coordinates. That means it does not automatically generate grid like MIKE 21 to map to a flood surface. An Arc GIS mapping tool was developed by Council officers was used to generate flood surfaces from the MIKE 11 model output. The main inputs of the tool are the model results in an excel spreadsheet and Digital Terrain Model (Appendix D: Arc GIS Mapping Tool Interface. The sources of the DTM data for this study are discussed in Section 4.3.6 . An example of the generated map is given in Figure 15.

Figure 15: An example of flood surface from 1 in 100 years flood


8. Conclusion

A MIKE11 hydraulic model for the Albert River catchment has been developed using DHI software version 2014 (service pack 3). The model has been reasonably calibrated against January 1974, January 2008, January 2012 and January 2013 historical flood events.

The calibrated model was subsequently used to simulate the design flood events. The hydraulic model has been developed using the latest available information. Council’s Designated Flood Level for City Plan 2015 for the Albert River catchment is being developed using this model.


9. References

1. City (2014a). Albert River Hydraulic Study, Report prepared by the City of Gold Coast, November 2014. TRACKS-#46601789-ALBERT RIVER CATCHMENT HYDRAULIC STUDY

2. City (2015a). Logan River Hydrological Study Addendum, Report prepared by the City of Gold Coast, July 2015. TRACKS-#50056335-LOGAN RIVER HYDROLOGICAL STUDY ADDENDUM REPORT JULY 2015

3. City (2014b). Logan River Hydrological Study, Report prepared by the City of Gold Coast, December 2014. TRACKS-#45737331-LOGAN_RIVER_HYDROLOGICAL_STUDY_DECEMBER_2014

4. City (2015b). Logan River (Woongoolba) Hydraulic Study, Report prepared by the City of Gold Coast, July 2015. TRACKS-#46776485-WOONGOOLBA (LOGAN RIVER CATCHMENT) HYDRAULIC STUDY DECEMBER 2014

5. GCCC (2013). Gold Coast City Council Storm Tide Study, Report prepared by GHD for Gold Coast City Council, February 2013. TRACKS-#39733283-STORM TIDE STUDY GHD - 412243 FEBRUARY 2013 ADDENDUM+APPENDICES

6. GCCC (2012). Logan River Catchment Hydraulic Study, Report prepared by the Council of the City of Gold Coast, June 2012. TRACKS-#30263231-LOGAN HYDRAULIC STUDY REPORT 2009

7. GCCC (2009). Logan River Flood Study–Hydrological Modelling Report prepared by the WRM, September 2009. TRACKS-#26580210-WRM LOGAN RIVER FLOOD STUDY HYDROLOGICAL REPORT 2009

8. GCCC (2007). Logan River Catchment Hydraulic Study Report prepared by the Council of the City of Gold Coast, August 2007. TRACKS-#19746090-REPORT LOGAN RIVER CATCHMENT - HYDRAULIC STUDY AUGUST 2007

9. PB (2004). Logan and Albert Rivers Mike 11 Flood Warning Model Report prepared by Parsons Brinckerhoff, May 2004. TRACKS-#44211387-LOGAN AND ALBERT RIVERS MIKE11 FLOOD WARNING MODEL AND TECHNICAL REPORT MAY 2004

10. AWE (1997). Southern Region of Council, Logan and Albert Rivers Flood Plain Modelling Study Report prepared by AWE, December 1997. TRACKS-#44187478-SOUTHERN REGION OF COUNCILS LOGAN AND ALBERT RIVERS FLOOD PLAIN MODELLING STUDY FINAL REPORT FS665


10. Appendices

Appendix A - Semidiurnal Tidal Plans


Appendix B – Hydrological Inputs and Sub Areas

Appendix B1 - Hydrologic Output and Hydraulic Input Location

Hydrologic Output

Hydraulic Input Location MIKE11

Branch Chainage (m) Type of Input

SC446_TH Cedar Creek 5000 Open Inflow

SC443_TH Albert River 20000 Open Inflow

SC444_LH Albert River 21359 Point Source



SC345_LH Albert River 30720 to 31902 Distributed Source

Appendix B2 - Logan River Hydrologic Catchment and Subareas


Appendix C: Structures Photo

Photo 1 Alan Wilke bridge at Stanmore Road, Luscombe

Photo 2 Stanmore causeway, Luscombe


Photo 3 Luscombe bridge at Beaudesert-Beenleigh Road, Luscombe

Photo 4 Luscombe weir


Photo 5 Chardon bridge at Chardon Bridge Road, Cedar Creek

Photo 6 Cedar Creek Road Bridge, Cedar Creek


Photo 7 Beaudesert-Beenleigh Road, Cedar Creek

Photo 8 Culverts at Rowe Lane, Cedar Creek


Photo 9 Photo down stream of culverts at Rowe Lane, Cedar Creek


Appendix D: Arc GIS Mapping Tool Interface

M11 Mapping Tool Parameters:

Mapping_DTM: The DTM that the flood surface is mapped too.

Adjusted_Centreline: As series of polylines connecting the M11 surface points.

IDW Breakline Radius: The extent that the IDW process will map too.

Expansion Inundation Threshold: A value that is the minimum amount that the water level must be above a dry cell in order to make it wet in the expansion/looping process. Default is 0.03.

XL_Results_File: The M11 XLS results file to be mapped.

File Name: The file name associated with the mapped flood surface. It must be enclosed in double quotations, i.e. “Albert_M11”.

Outer Radius: This value must be a negative value that is less than the IDW Breakline Radius. For most operations it should be the same value as the IDW Breakline Radius but negative.

Working Files.gdb: The default gdb where the working files are located and the results written too.


The tool produces four outputs:

The Flood Surface: This is the final output of the tool. The final mapped surface of the M11 Results file.

Base Main: This is the base flood map created before the expansion process has started.

Breaklines: These are the breaklines used to create the base flood map.

Num_Iterations.txt: A txt file that records the number of iterations the Loop Module ran.


For more information P 1300 GOLDCOAST (1300 465 326) W cityofgoldcoast.com.au

Documents

Albert River Catchment Hydraulic Study · 2019. 6. 23. · TRACKS-#50669992-v2-ALBERT_RIVER_CATCHMENT_HYDRAULIC_STUDY_2015.docx Page 8 of 36 3. Background 3.1 Catchment Description